MedWorm.com provides a medical RSS filtering service. Over 6000 RSS medical sources are combined and output via different filters. This feed contains the latest items from the 'Hormones and Behavior' source. Fri, 19 Mar 2010 15:17:41 +0100 http://www.medworm.com/index.php?rid=3374968&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20226788%26dopt%3DAbstract Authors: Puts DA, Cárdenas RA, Bailey DH, Burriss RP, Jordan CL, Breedlove SM Multiple studies report relationships between circulating androgens and performance on sexually differentiated spatial cognitive tasks in human adults, yet other studies find no such relationships. Relatively small sample sizes are a likely source of some of these discrepancies. The present study thus tests for activational effects of testosterone (T) using a within-participants design by examining relationships between diurnal fluctuations in salivary T and performance on a male-biased spatial cognitive task (Mental Rotation Task) in the largest sample yet collected: 160 women and 177 men. T concentrations were unrelated to within-sex variation in mental rotation performance in both sexes. Further, betw... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3374968 Wed, 10 Mar 2010 00:00:00 +0100 3374968 http://www.medworm.com/index.php?rid=3363164&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20223236%26dopt%3DAbstract Authors: Wu D, Gore AC Reproductive aging in males is characterized by a diminution in sexual behavior beginning in middle age. We investigated the relationships among testosterone, androgen receptor (AR) and estrogen receptor alpha (ERalpha) cell numbers in the hypothalamus, and their relationship to sexual performance in male rats. Young (3months) and middle-aged (12months) rats were given sexual behavior tests, then castrated and implanted with vehicle or testosterone capsules. Rats were tested again for sexual behavior. Numbers of AR and ERalpha immunoreactive cells were counted in the anteroventral periventricular nucleus and the medial preoptic nucleus, and serum hormones were measured. Middle-aged intact rats had significant impairments of all sexual behavior measures compared t... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3363164 Mon, 08 Mar 2010 00:00:00 +0100 3363164 http://www.medworm.com/index.php?rid=3363163&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20223237%26dopt%3DAbstract Authors: Sprague RS, Breuner CW Fledging is a major life transition for birds, when juveniles move from the safety of a nest into an environment where they must find food and avoid predators. The timing of fledging within a season can have significant effects on future survival and breeding success. Proximate triggers of fledging are unknown: though wing development is likely a primary factor, other physiological changes, such as elevated plasma corticosterone (CORT), may affect fledging behavior. Laysan Albatross (Phoebastria immutabilis) chicks have an extended post-hatching period during which they reach 150% of adult mass. However, approaching fledging, chicks fast for days to weeks and lose mass while still putting energy into feather growth. We evaluated chick morphology and phys... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3363163 Mon, 08 Mar 2010 00:00:00 +0100 3363163 http://www.medworm.com/index.php?rid=3363162&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20223238%26dopt%3DAbstract Authors: Guptarak J, Sarkar J, Hiegel C, Uphouse L The selective serotonin reuptake inhibitor (SSRI), fluoxetine (Prozac(R)), is an effective antidepressant that is also prescribed for other disorders (e.g. anorexia, bulimia, and premenstrual dysphoria) that are prevalent in females. However, fluoxetine also produces sexual side effects that may lead patients to discontinue treatment. The current studies were designed to evaluate several predictions arising from the hypothesis that serotonin 1A (5-HT(1A)) receptors contribute to fluoxetine-induced sexual dysfunction. In rodent models, 5-HT(1A) receptors are potent negative modulators of female rat sexual behavior. Three distinct experiments were designed to evaluate the contribution of 5-HT(1A) receptors to the effects of fluoxetine. I... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3363162 Mon, 08 Mar 2010 00:00:00 +0100 3363162 http://www.medworm.com/index.php?rid=3350656&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20211183%26dopt%3DAbstract Authors: Wetherington CL PMID: 20211183 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3350656 Fri, 05 Mar 2010 00:00:00 +0100 3350656 http://www.medworm.com/index.php?rid=3350655&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20211184%26dopt%3DAbstract Authors: Landys MM, Goymann W, Schwabl I, Trapschuh M, Slagsvold T Plasma testosterone increases during breeding in many male vertebrates and has long been implicated in the promotion of aggressive behaviors relating to territory and mate defense. Males of some species also defend territories outside of the breeding period. For example, the European nuthatch (Sitta europaea) defends an all-purpose territory throughout the year. To contribute to the growing literature regarding the hormonal correlates of non-breeding territoriality, we investigated the seasonal testosterone and corticosterone profile of male (and female) nuthatches and determined how observed hormone patterns relate to expression of territorial aggression. Given that non-breeding territoriality in the nuthatch relates t... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3350655 Fri, 05 Mar 2010 00:00:00 +0100 3350655 http://www.medworm.com/index.php?rid=3350657&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20206628%26dopt%3DAbstract In this study, we examined the prevalence of proactive/reactive stress coping styles in wild-caught short-tailed singing mice (Scotinomys teguina). We compared stress responses to spontaneous singing, a social and reproductive behavior that characterizes this species. To establish proactive/reactive profiles for singing mice, we measured exploratory and anxiety behavior using an open-field behavioral test. We examined correlations between open-field behaviors and fecal corticosterone (CORT) metabolites, baseline plasma CORT and stress-induced CORT. Mice with proactive behavioral responses in the open-field had higher fecal CORT titers than reactive males, but did not differ in baseline or stress-induced plasma CORT. We suggest that individual differences in CORT metabolism may contribute t... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3350657 Wed, 03 Mar 2010 00:00:00 +0100 3350657 http://www.medworm.com/index.php?rid=3350658&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20206181%26dopt%3DAbstract Authors: Xu XH, Zhang J, Wang YM, Ye YP, Luo QQ Bisphenol-A (BPA) has been shown to influence development of the brain and behaviors. The purpose of the present report was to investigate the effects of perinatal exposure to BPA on learning/memory and its mechanism of action, especially focusing on N-methyl-D-aspartate receptor (NMDAR). Perinatal maternal exposure to BPA at 0.5, 5, and 50mg/kg/d significantly extended the escape length to find the hidden platform in Morris water maze, and BPA at 0.5 or 5mg/kg/d markedly decreased the percentage of time spent in the quadrant where the platform had been during training both in postnatal day (PND) 21 and PND56 mice. The results of passive avoidance test showed that the error frequency to step down from a platform after received footshock w... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3350658 Tue, 02 Mar 2010 00:00:00 +0100 3350658 http://www.medworm.com/index.php?rid=3332048&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20193686%26dopt%3DAbstract We examined fat pad weight (brown, retroperitoneal, inguinal & epididymal); inguinal adipocyte size and number; and leptin, adiponectin, corticosterone & creatinine levels. We also examined body weight, feeding efficiency and spontaneous intake. Early voluntary exercise reduced intake, adiposity and leptin in the OLETF males following a sharp reduction in adipocyte size despite a significant increase in fat cell number. Exercising males from the lean LETO control strain presented stable intake, but reduced body fat, feeding efficiency and increased plasma creatinine, suggesting an increment in muscle mass. OLETF females showed reduced feeding efficiency and liver fat, and a significant increase in brown fat. Exercising LETO control females increased intake, body weight and creatini... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3332048 Fri, 26 Feb 2010 00:00:00 +0100 3332048 http://www.medworm.com/index.php?rid=3323253&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20188733%26dopt%3DAbstract Effects of social experience on subsequent sexual performance in naïve male Japanese quail (Coturnix japonica). Horm Behav. 2010 Feb 24; Authors: Cornil CA, Ball GF On their first sexual encounter, naïve male Japanese quail will attend to and approach a female; they sometimes mount but they do not always copulate. During the second encounter, most males successfully copulate. Although sexual experience facilitates subsequent sexual interactions, sensory cues provided by females, independent of any sexual encounter, may also enhance sexual performance. To investigate whether previous exposure to a conspecific affects subsequent sexual behavior, we allowed inexperienced males to observe an empty box, or a conspecific consisting of either an experienced female or male fo... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3323253 Wed, 24 Feb 2010 00:00:00 +0100 3323253 http://www.medworm.com/index.php?rid=3323254&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20188104%26dopt%3DAbstract Authors: Ganswindt A, Muenscher S, Henley M, Henley S, Heistermann M, Palme R, Thompson P, Bertschinger H Sexual activity in mature male African elephants is predominantly associated with the occurrence of musth, a state or condition which refers to a set of physical, physiological and behavioral characteristics, including an elevation in androgen levels. Although musth appears to be energetically costly, the degree to which it is associated with changes in adrenal endocrine function (e.g., glucocorticoid output) is still unclear. To investigate the possible effect of musth on adrenocortical function, and the impact of socioecological changes on androgen and glucocorticoid levels, six adult African elephant bulls were followed for 13months in the Kruger National Park, South Africa, and... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3323254 Tue, 23 Feb 2010 00:00:00 +0100 3323254 http://www.medworm.com/index.php?rid=3298806&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20171966%26dopt%3DAbstract We examined cocaine's acute neuroendocrine effects on P and 3alpha, 5alpha-THP levels, as well as its effects on acute psychomotor stimulation, anxiety, and sexual behaviors. Among rats that had P and/or 3alpha, 5alpha-THP levels increased in response to cocaine, enhanced acute psychomotor stimulation was observed. Results suggest that cocaine produces U-shaped curves for progestogens, and anxiety-like behaviors. Male rats were less susceptible to these effects of cocaine than were proestrous or diestrous female rats. However, cocaine's disruption of sexual behaviors was similar among males and proestrous females. These data suggest a complex interaction between hormonal milieu and the neuroendocrine and behavioral effects of cocaine. PMID: 20171966 [PubMed - as supplied by publisher] ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3298806 Thu, 18 Feb 2010 00:00:00 +0100 3298806 http://www.medworm.com/index.php?rid=3298805&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20171967%26dopt%3DAbstract Authors: Henley CL, Nunez AA, Clemens LG In the rat, neonatal administration of testosterone propionate to a castrated male causes masculinization of behavior. However, if an intact male is treated neonatally with testosterone (hyper-androgen condition), male sexual behavior in adulthood is disrupted. There is a possibility that the hyper-androgen treatment is suppressing male sexual behavior by altering the male's partner preference and thereby reducing his motivation to approach the female. If so, this would suggest that exposure to supra-physiological levels of androgen during development may result in the development of male-oriented partner preference in the male. To test this idea, male rats were treated either postnatally or prenatally with testosterone, and partner preference a... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3298805 Thu, 18 Feb 2010 00:00:00 +0100 3298805 http://www.medworm.com/index.php?rid=3298807&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20171225%26dopt%3DAbstract Authors: Tilgar V, Saag P, Külavee R, Mänd R The extended secretion of stress hormones in fully developed animals is known to have profound consequences. However, little is known about the effects of stress on the behaviour and physiology of free-living young animals, and how such responses relate to each other. We repeatedly (during five consecutive days, one hour per day) exposed the nestlings of a passerine bird, the pied flycatcher (Ficedula hypoleuca), to recordings of nestling distress calls and examined their behavioural and physiological responses to the stressor on the first and the last day of the experiment (on days 9 and 13 post-hatch, respectively). In comparison with control siblings, stressed nestlings reduced the amount of time that they devoted to vocalizatio... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3298807 Wed, 17 Feb 2010 00:00:00 +0100 3298807 http://www.medworm.com/index.php?rid=3288570&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20156440%26dopt%3DAbstract Authors: Clinton SM, Bedrosian TA, Abraham AD, Watson SJ, Akil H Selective breeding of rats exhibiting differences in novelty-induced locomotion revealed that this trait predicts several differences in emotional behavior. Bred High Responders (bHRs) show exaggerated novelty-induced locomotion, aggression, and psychostimulant self-administration, compared to bred Low Responders (bLRs), which are inhibited and prone to anxiety- and depression-like behavior. Our breeding studies highlight the heritability of the bHR/bLR phenotypes, although environmental factors like maternal care also shape some aspects of these traits. We previously reported that HR vs. LR mothers act differently, but it was unclear whether their behaviors were genetically driven or influenced by their pups. The present... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3288570 Fri, 12 Feb 2010 00:00:00 +0100 3288570 http://www.medworm.com/index.php?rid=3288569&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20156441%26dopt%3DAbstract We examined fat pad weight (brown, retroperitoneal, inguinal & epididymal); inguinal adipocyte size and number; and plasma leptin, oxytocin & creatinine levels. We also examined body weight, feeding efficiency and spontaneous intake after release from food-restriction. The results showed that chronic food restriction produced significant reductions in adiposity parameters, hormones and body weight, while early food restriction successfully reduced long term body weight, intake and adiposity, without affecting plasma measurements. Early (and chronic) dieting produced promising long term effects that may imply the reorganization of both peripheral and central mechanisms that determine energy balance and further support the theory suggesting that early interventions may effectively mo... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3288569 Fri, 12 Feb 2010 00:00:00 +0100 3288569 http://www.medworm.com/index.php?rid=3288568&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20156442%26dopt%3DAbstract Authors: Balthazart J, Pradhan DS, Newman AE, Wacker DW, Wingfield JC, Schlinger BA, Soma KK PMID: 20156442 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3288568 Fri, 12 Feb 2010 00:00:00 +0100 3288568 http://www.medworm.com/index.php?rid=3258718&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20138885%26dopt%3DAbstract Authors: Pan YF, Chen XR, Wu MN, Ma CG, Qi JS Amyloid beta protein (Abeta) is thought to be responsible for loss of memory in Alzheimer's disease (AD). A significant decrease in [Arg(8)]-Vasopressin (AVP) has been found in the AD brain and in plasma; however, it is unclear whether this decrease in AVP is involved in Abeta-induced impairment of spatial cognition and whether AVP can protect against Abeta-induced deficits in cognitive function. The present study examined the effects of intracerebroventricular (i.c.v.) injection of AVP on spatial learning and memory in the Morris water maze test and investigated the potential protective function of AVP against Abeta-induced impairment in spatial cognition. The results were as follows: (1) I.C.V. injection of 25nmol Abeta(25-35) resulted in... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3258718 Thu, 04 Feb 2010 00:00:00 +0100 3258718 http://www.medworm.com/index.php?rid=3240214&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20122934%26dopt%3DAbstract Authors: Kuzawa C, Gettler LT, Huang YY, McDade TW Testosterone (T) is lower among fathers and men in committed relationships, suggesting that the hormone mediates the trade-off between mating and parenting effort. The function of T in women, and responses of the hormone to relationships or motherhood, are less well understood. Here we report relationships between T and pairbonding and motherhood in a random sample of 67 women (20.9 to 22.4 years old) participating in a population-based birth cohort study in the Philippines. Testosterone was measured in saliva collected at bedtime and at waking the following morning to capture circadian dynamics. Compared to non-mothers and non-pairbonded women, mothers and pairbonded women had 32% (p<0.0001) and 23% (p<0.004) lower waking T, res... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3240214 Fri, 29 Jan 2010 00:00:00 +0100 3240214 http://www.medworm.com/index.php?rid=3232288&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20116379%26dopt%3DAbstract Authors: Pradhan DS, Newman AE, Wacker DW, Wingfield JC, Schlinger BA, Soma KK In male song sparrows (Melospiza melodia), territorial challenges during the breeding season can rapidly increase circulating levels of testosterone (T). During the non-breeding season, male song sparrows are highly aggressive, but the gonads are regressed and plasma T levels are non-detectable and unaffected by territorial challenges. The pro-hormone dehydroepiandrosterone (DHEA) is elevated in song sparrow plasma and brain during the non-breeding season and may be locally converted to sex steroids in the brain to regulate aggression. The enzyme 3beta-hydroxysteroid dehydrogenase/Delta5-Delta4 isomerase (3beta-HSD) converts DHEA to androstenedione (AE) using the cofactor NAD(+), and this is a critical rate-... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3232288 Wed, 27 Jan 2010 00:00:00 +0100 3232288 http://www.medworm.com/index.php?rid=3221444&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20109458%26dopt%3DAbstract Authors: Keller M, Pawluski JL, Brock O, Douhard Q, Bakker J In rodent species, sexual differentiation of the brain for many reproductive processes depends largely on estradiol. This was recently confirmed again by using the alpha-fetoprotein knockout (AFP-KO) mouse model, which lacks the protective actions of alpha-fetoprotein against maternal estradiol and as a result represents a good model to determine the contribution of prenatal estradiol to the sexual differentiation of the brain and behavior. Female AFP-KO mice were defeminized and masculinized with regard to their neuroendocrine responses as well as sexual behavior. Since parental behavior is also strongly sexually differentiated in mice, we used the AFP-KO mouse model here to ask whether parental responses are differentiated ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3221444 Mon, 25 Jan 2010 00:00:00 +0100 3221444 http://www.medworm.com/index.php?rid=3221443&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20109459%26dopt%3DAbstract Authors: Kouzakova M, Baaren RV, Knippenberg AV As inherently social animals, humans are very sensitive to behavioral signals from other members of their group. Nonconscious imitation of conspecifics' behavior (also called social mirroring) is a common manner in which people express their sense of similarity and affiliation with others. This evolutionary important behavioral repertoire has been referred to as 'social glue' as it cultivates pro-social behaviors that foster one's acceptance by the group as well as sustain societal unity. Lack of behavior imitation therefore serves a subtle cue signaling rejection by others. Because being rejected is a stressful experience that is known to raise cortisol levels in humans and other primates such as baboons, we reasoned that not being imita... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3221443 Mon, 25 Jan 2010 00:00:00 +0100 3221443 http://www.medworm.com/index.php?rid=3214702&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20100486%26dopt%3DAbstract Authors: Gabor CR, Grober MS Hormones play a critical role in the regulation of vertebrate mating behavior, including receptivity, and several components of mate choice. However, less is known about the role of these chemical messengers in mediating behavior associated with premating reproductive isolation. The bisexual-unisexual mating complex of sailfin mollies, Poecilia latipinna, and Amazon mollies, Poecilia formosa (sexual parasites of sailfins) has been a model system for studying ultimate mechanisms of species recognition. However proximate mechanisms, such as variation in hormone levels, have not been examined. We paired male sailfin mollies with either female conspecifics or Amazon mollies and obtained water-borne hormone samples before and after mating for all fish. We measur... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3214702 Fri, 22 Jan 2010 00:00:00 +0100 3214702 http://www.medworm.com/index.php?rid=3214701&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20100487%26dopt%3DAbstract Authors: Viveros MP, Díaz F, Mateos B, Rodríguez N, Chowen JA Pathological outcomes, including metabolic and endocrine disturbances, of maternal deprivation (MD) in Wistar rats depend on gender and the timing of deprivation during development. We analyzed the effect of MD between postnatal days 9 and 10, a critical period in hypothalamic development, on circulating hormones and local production of trophic factors involved in this process, as well as on markers of cell turnover and maturation. Males and females were studied 12 and 24 hours after MD and 12 hours (MD36) after returning the dam to her pups. Circulating corticosterone levels were increased and glucose and leptin levels decreased throughout the study in both sexes. Hypothalamic mRNA levels of leptin receptor increa... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3214701 Fri, 22 Jan 2010 00:00:00 +0100 3214701 http://www.medworm.com/index.php?rid=3214700&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20100488%26dopt%3DAbstract Authors: Schmidt MV, Scharf SH, Liebl C, Harbich D, Mayer B, Holsboer F, Müller Major depression is one of the most prevalent stress-related psychiatric diseases. Next to environmental influences such as chronic social stress, gender is among the strongest risk factors for major depression, with women having a twice as high risk to develop the disease compared to men. While there is abundant literature on the effects of chronic social stress in male rodents, there is a serious lack of information on gender-specific effects. Especially in mice, which due to the wide availability of transgenic lines offer a unique opportunity to study geneenvironment interactions, there is no existing model of chronic social stress that is applicable to both sexes. We here describe the effects of c... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3214700 Fri, 22 Jan 2010 00:00:00 +0100 3214700 http://www.medworm.com/index.php?rid=3208814&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20096699%26dopt%3DAbstract Authors: Wei L, David A, Duman RS, Anisman H, Kaffman A A better understanding of the molecular and cellular mechanisms by which early life stress (ELS) modifies brain development and adult behavior is necessary for diagnosing and treating psychopathology associated with exposure to ELS. For historical reasons most of the work in rodents has been done in rats and attempts to establish robust and reproducible paradigms in the mouse have proven to be challenging. Here we show that under normal rearing conditions, increased levels of postnatal maternal care are associated with a decrease in anxiety-like behavior in BALB/cByj offspring. Brief daily pup-dam separation (BDS) during the postnatal period was associated with increased postnatal maternal care but was surprisingly associated with... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3208814 Wed, 20 Jan 2010 00:00:00 +0100 3208814 http://www.medworm.com/index.php?rid=3190008&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20080100%26dopt%3DAbstract This study investigates how OT interacts with two well-studied determinants of cooperative behavior: incentives and social information. Participants received OT or a placebo and played two economic games: a Coordination Game (with strong incentives to cooperate) and a Prisoner's Dilemma (with weak cooperative incentives). OT enhanced cooperation only when social information was present, and this effect was significantly more pronounced in the Coordination Game. When social information was lacking, OT surprisingly decreased cooperation. Consistent with the well-established role of OT in trust-building and in social cognition, social information appears to be crucial for OT to boost cooperative expectations in an interdependent social interaction that provides incentives to cooperate. When t... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3190008 Thu, 14 Jan 2010 00:00:00 +0100 3190008 http://www.medworm.com/index.php?rid=3190012&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20079739%26dopt%3DAbstract This study sheds light on when and under what circumstances estradiol gains control over spatial navigation behavior in the female rat. PMID: 20079739 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3190012 Wed, 13 Jan 2010 00:00:00 +0100 3190012 http://www.medworm.com/index.php?rid=3190011&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20079740%26dopt%3DAbstract This study was undertaken to examine the relationship between endogenous sex hormone levels and cognitive functioning in healthy older men using a comprehensive battery of neuropsychological tests and measurement of serum sex hormone levels. Verbal learning and memory, visual-motor processing, spatial abilities, working memory and attention, and levels of testosterone and estradiol were evaluated in fifty-four healthy older men. Regression analyses revealed significant curvilinear associations between working memory function and both free and bioavailable testosterone levels, suggesting that an optimal hormone level may exist for maximal performance on tasks of executive/frontal lobe functioning. However, no other relationships were evident between either estradiol or testosterone levels a... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3190011 Wed, 13 Jan 2010 00:00:00 +0100 3190011 http://www.medworm.com/index.php?rid=3190010&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20079741%26dopt%3DAbstract Authors: Azpeleta C, Martínez-Álvarez RM, Delgado MJ, Isorna E, Pedro ND The present study focused on the effects of a subchronic melatonin treatment on locomotor activity and cortisol plasma levels in goldfish. We compared two different administration routes: peripheral (10 microg/g body weight) versus central (1 microg/microl) injections of melatonin for 7 or 4 days, respectively. Daily locomotor activity, including both diurnal and nocturnal activities, food anticipatory activity and circulating cortisol at 11:00 (under 24 h food deprivation and 17 h postinjection) were significantly reduced after repeated intraperitoneal injections with melatonin for 7 days, but not after intracerebroventricular treatment. Taking in mind the anoretic effect of melatonin in this species, w... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3190010 Wed, 13 Jan 2010 00:00:00 +0100 3190010 http://www.medworm.com/index.php?rid=3190009&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20079742%26dopt%3DAbstract Authors: Arndt SS, Lohavech D, Van't Klooster J, Ohl F Co-species housing of mice and rats is common practice at most breeding facilities and research laboratories, neglecting the possible effects on the animals. We investigated physiological as well as behavioral stress-reactivity in mice and rats which were either derived from a co-species or species-separated housing condition at the breeding facilities. The animals were kept under the housing condition they were used to or assigned to the opposite one. Co-species housing had a significant impact on acute stress reactivity in mice and rats but only if they were used to this housing condition throughout their lives. Moreover, the stress-effects appeared to be long lasting. Assigning animals, derived from a species-separated housing c... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3190009 Wed, 13 Jan 2010 00:00:00 +0100 3190009 http://www.medworm.com/index.php?rid=3190013&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20079357%26dopt%3DAbstract Authors: Arakawa H, Arakawa K, Deak T Infected animals are avoided by conspecifics, suggesting that the inflammatory cascade may play a significant role in odor communication. Injection of male rats with the bacterial mimetic, lipopolysaccharide (LPS, 100 microg/kg, i.p.), decreased investigation through a wire-mesh partition between healthy male partners. This avoidance response was observed in adult males in response to soiled bedding collected from sick rats, regardless of whether LPS was injected peripherally (100 microg/kg, i.p.) or centrally (0.25 or 2.5 microg, icv). The release of sickness-related odor cues was dose-dependently blocked by icv infusion of the anti-inflammatory cytokine, Interleukin-10 (IL-10; 20 or 200 ng), and reproduced by icv infusion of pro-inflammatory cyto... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3190013 Tue, 12 Jan 2010 00:00:00 +0100 3190013 http://www.medworm.com/index.php?rid=3167533&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20060000%26dopt%3DAbstract Authors: Bergman K, Glover V, Sarkar P, Abbott D, O'Connor TG Fetal programming is emerging as a major conceptual model for understanding developmental origins of health and disease, including behavioral outcomes. As part of a larger study of prenatal stress and child development, we examined the association between prenatal hormone exposure and fear reactivity, a temperament dimension that is a predictor of long-term behavioral adjustment. Amniotic fluid was collected from a sample of women undergoing clinically indicated amniocentesis for later analysis of cortisol and testosterone. Children with normal birth outcomes were recalled for follow-up assessment at 17 months, at which time we administered an observational assessment of temperament (lab-TAB; n=108). Information on pregnancy... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3167533 Tue, 05 Jan 2010 00:00:00 +0100 3167533 http://www.medworm.com/index.php?rid=3156859&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20053349%26dopt%3DAbstract Authors: Menke LA, Sas TC, Visser M, Kreukels BP, Stijnen T, Zandwijken GR, de Muinck Keizer-Schrama SM, Otten BJ, Wit JM, Cohen-Kettenis PT The weak androgen oxandrolone (Ox) increases height gain in growth-hormone (GH) treated girls with Turner syndrome (TS), but may also give rise to virilizing side effects. To assess the effect of Ox, at a conventional and low dosage, on behavior, aggression, romantic and sexual interest, mood, and gender role in GH-treated girls with TS, a randomized, placebo-controlled, double-blind study was conducted. 133 patients were treated with GH (1.33 mg/m(2)/day) from baseline, combined with placebo (Pl), Ox 0.03 mg/kg/day, or Ox 0.06 mg/kg/day from the age of eight, and with estrogens from the age of twelve. The child behavior checklist (CBCL), Junior D... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3156859 Sun, 03 Jan 2010 00:00:00 +0100 3156859 http://www.medworm.com/index.php?rid=3156858&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20053350%26dopt%3DAbstract Authors: Ball ER, Caniglia MK, Wilcox JL, Overton KA, Burr MJ, Wolfe BD, Sanders BJ, Wisniewski AB, Wrenn CC Endocrine disruptors, chemicals that disturb the actions of endogenous hormones, have been implicated in birth defects associated with hormone-dependent development. Phytoestrogens are a class of endocrine disruptors found in plants. In the current study we examined the effects of exposure at various perinatal time periods to genistein, a soy phytoestrogen, on reproductive development and learning in male rats. Dams were fed genistein-containing (5 mg/kg feed) food during both gestation and lactation, during gestation only, during lactation only, or during neither period. Measures of reproductive development and body mass were taken in the male offspring during postnatal develop... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3156858 Sun, 03 Jan 2010 00:00:00 +0100 3156858 http://www.medworm.com/index.php?rid=3143294&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20045413%26dopt%3DAbstract This study aimed to evaluate neuroendocrine and cardiovascular responses together with changes in brain asymmetry following an anger mood induction laboratory task. Previous research has shown an increase in heart rate and blood pressure when anger is experienced. Increased Testosterone and decreased Cortisol in response to anger and aggressive behavior have also been reported. With regard to asymmetrical frontal brain activity and emotion, the valence model links negative affect (as anger) to the right hemisphere while the motivational direction model links approach-related emotions (as anger) to the left hemisphere. From the subjective perception and from the neuroendocrine and cardiovascular response of the subjects, we can conclude that the self-referent statements Anger Induction meth... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3143294 Wed, 30 Dec 2009 00:00:00 +0100 3143294 http://www.medworm.com/index.php?rid=3143293&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20045414%26dopt%3DAbstract This study analyzes the effect of OT administration (at 0830 and 1430h) on the consumption of water and hypertonic NaCl (1.5%). In the first experiment, injections of OT increased the intake of hypertonic NaCl (but not of water) in food-deprived rats but not in ad lib-fed animals during the second 12 h (2030 to 0830) of the treatment day. The net concentration of the fluid consumed by OT/deprived animals was close to isotonic. In the second experiment, the initial effect of OT administration was an increase in urine volume and urinary sodium excretion and concentration by food-deprived animals during the first 12 h (0830 to 2030). These findings suggest that in food-deprived animals, systemic administration of OT induces NaCl intake as a consequence of previous urine loss and urinary sodiu... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3143293 Wed, 30 Dec 2009 00:00:00 +0100 3143293 http://www.medworm.com/index.php?rid=3143295&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20044999%26dopt%3DAbstract Authors: Shah SN, Nyby JG Ghrelin is a peptide hormone released by the stomach that stimulates hunger. Ghrelin also suppresses reproductive physiology by inhibiting the HPG axis. However, to our knowledge, our results are the first to demonstrate ghrelin's quick suppression of sex-hormone-regulated behaviors. In Experiment 1, 2 orexigenic i.p. ghrelin injections (0.165 mg/kg and 0.33 mg/kg) suppressed male courtship behavior (ultrasonic calling to a female) and intermale aggression (latency to attack a stimulus male) 20 min following administration. Experiment 2 (examining only the 0.33 mg/kg dose ) replicated ghrelin's suppression of ultrasonic calling and intermale aggression, however a third behavior, preference for volatile female odors (20 min following administration), was not si... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3143295 Tue, 29 Dec 2009 00:00:00 +0100 3143295 http://www.medworm.com/index.php?rid=3126985&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20036242%26dopt%3DAbstract In this study, we measured testosterone levels in plasma throughout the reproductive cycle of the Mongolian gerbil. Testosterone concentrations were correlated with paternal care as well as aggression. We also examined whether there is a trade-off between paternal behavior and aggression in this mammal. Our results show that Mongolian gerbil testosterone levels do not decrease when the males give paternal care. Likewise, male Mongolian gerbils exhibit high levels of aggression while displaying paternal behavior, indicating that there is no trade-off between aggression and paternal behavior. More studies are needed to determine whether testosterone is involved in the regulation of paternal behavior in this rodent. PMID: 20036242 [PubMed - as supplied by publisher] (Source: Hormones and ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3126985 Wed, 23 Dec 2009 00:00:00 +0100 3126985 http://www.medworm.com/index.php?rid=3123612&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20034495%26dopt%3DAbstract This study investigated whether women's interest in visual sexual stimuli varied with their hormonal state. Viewing times of 30 women, 15 normal cycling (NC) and 15 oral contracepting (OC), to sexually explicit photos were measured at three different times. NC Women were tested during their menstrual, periovulatory, and luteal phases, and OC Women were tested at equivalent temporal intervals. Subjects viewed stimuli as long as desired, thus viewing time measured subject interest. Subjective ratings of stimulus sexual attractiveness were obtained on each test. There was no overall relationship between menstrual cycle phase and viewing time. However the participant's menstrual cycle phase during first exposure to sexual stimuli predicted subsequent interest in sexual stimuli during the next ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3123612 Mon, 21 Dec 2009 00:00:00 +0100 3123612 http://www.medworm.com/index.php?rid=3115868&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20026119%26dopt%3DAbstract Authors: Segarra AC, Agosto-Rivera JL, Febo M, Lugo-Escobar N, Menéndez-Delmestre R, Puig-Ramos A, Torres-Diaz YM PMID: 20026119 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3115868 Thu, 17 Dec 2009 00:00:00 +0100 3115868 http://www.medworm.com/index.php?rid=3115870&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20025881%26dopt%3DAbstract Authors: Smith AS, Agmo A, Birnie AK, French JA The establishment and maintenance of stable, long-term male-female relationships, or pair bonds, are marked by high levels of mutual attraction, selective preference for the partner, and high rates of sociosexual behavior. Central oxytocin (OT) affects social preference and partner-directed social behavior in rodents, but the role of this neuropeptide has yet to be studied in heterosexual primate relationships. The present study evaluated whether the OT system plays a role in the dynamics of social behavior and partner preference during the first three weeks of cohabitation in male and female marmosets, Callithrix penicillata. OT activity was stimulated by intranasal administration of OT, and inhibited by oral administration of a non-pept... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3115870 Tue, 15 Dec 2009 00:00:00 +0100 3115870 http://www.medworm.com/index.php?rid=3115869&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20025882%26dopt%3DAbstract Authors: Guarraci FA Preclinical and clinical research investigating female sexual motivation has lagged behind research on male sexual function. The present review summarizes recent advances in our understanding of the specific roles of various brain areas, as well as our understanding of the role of dopaminergic neurotransmission in sexual motivation of the female rat. A number of behavioral paradigms that can be used to thoroughly evaluate sexual behavior in the female rat are first discussed. Although traditional assessment of the reflexive, lordosis posture has been useful in understanding the neuroanatomical and neurochemical systems that contribute to copulatory behavior, the additional behavioral paradigms described in this review have helped us expand our understanding of appe... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3115869 Tue, 15 Dec 2009 00:00:00 +0100 3115869 http://www.medworm.com/index.php?rid=3101279&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20006614%26dopt%3DAbstract Authors: Saridjan NS, Huizink AC, Koetsier JA, Jaddoe VW, Mackenbach JP, Hofman A, Kirschbaum C, Verhulst FC, Tiemeier H Dysregulation of diurnal cortisol secretion patterns may explain the link between adversities early in life and later mental health problems. However, few studies have investigated the influence of social disadvantage and family adversity on the hypothalamic-pituitary-adrenal (HPA) axis early in life. In 366 infants aged 12-20 months from the Generation R Study, a population-based cohort from fetal life onwards, parents collected saliva samples from their infant at 5 moments during one day. The area under the curve (AUC), the cortisol awakening response (CAR) and the diurnal cortisol slope were calculated as different composite measures of the diurnal cortisol rhythm... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3101279 Fri, 11 Dec 2009 00:00:00 +0100 3101279 http://www.medworm.com/index.php?rid=3101280&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D20004662%26dopt%3DAbstract Authors: Frohmader KS, Pitchers KK, Balfour ME, Coolen LM Drugs of abuse act on the brain circuits mediating motivation and reward associated with natural behaviors. There is ample evidence that drugs of abuse impact male and female sexual behavior. First, the current review discusses the effect of drugs of abuse on sexual motivation and performance in male and female humans. In particular, we discuss the effects of commonly abused drugs including psychostimulants, opiates, marijuana/THC and alcohol. In general, drug use affects sexual motivation, arousal, as performance, and is commonly associated with increased sexual risk behaviors. Second, studies on effects of systemic administration of drugs of abuse on sexual behavior in animals are reviewed. These studies analyze effects on sex... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3101280 Tue, 08 Dec 2009 00:00:00 +0100 3101280 http://www.medworm.com/index.php?rid=3068046&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19968991%26dopt%3DAbstract Authors: Hubbard CS, Dolence EK, Rose JD Stress-induced release or central administration of corticotropin-releasing factor (CRF) enhances locomotion in a wide range of vertebrates, including the roughskin newt, Taricha granulosa. Although CRF's stimulatory actions on locomotor behavior are well established, the target neurons through which CRF exerts this effect remain unknown. To identify these target neurons, we utilized a fluorescent conjugate of CRF (CRF-TAMRA 1) to track this peptide's internalization into reticulospinal and other neurons in the medullary reticular formation (MRF), a region critically involved in regulating locomotion. Epifluorescent and confocal microscopy revealed that CRF-TAMRA 1 was internalized by diverse MRF neurons, including reticulospinal neurons retrogr... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3068046 Fri, 04 Dec 2009 00:00:00 +0100 3068046 http://www.medworm.com/index.php?rid=3068047&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19962378%26dopt%3DAbstract Authors: Edelstein RS, Stanton SJ, Henderson MM, Sanders MR Estradiol has been linked with attachment and caregiving processes in humans and other mammals; however, relations between estradiol and personality constructs relevant to intimate relationships have not yet been explored. In the present sample of 100 adult participants (52 men, 48 women), we examined endogenous estradiol levels in relation to two personality constructs that predict comfort with and desire for close, intimate relationships-attachment style and implicit intimacy motivation. In both men and women, estradiol levels were predicted by an interaction between a dimension of attachment style-attachment avoidance-and implicit intimacy motivation. Specifically, the highest estradiol levels were observed among participan... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3068047 Wed, 02 Dec 2009 00:00:00 +0100 3068047 http://www.medworm.com/index.php?rid=3060001&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19958772%26dopt%3DAbstract In conclusion, our data are consistent with the notion that genetic damage in the form of DNA breakage in brain cells induced by sleep deprivation overrides the effects related to endogenous female sex hormones. PMID: 19958772 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3060001 Mon, 30 Nov 2009 00:00:00 +0100 3060001 http://www.medworm.com/index.php?rid=3052879&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19948175%26dopt%3DAbstract Authors: Waldherr M, Nyuyki K, Maloumby R, Bosch OJ, Neumann ID Beneficial effects of sexual activity and mating on the responsiveness to environmental stress can be observed in humans and other mammalian species alike, but the underlying neurobiological mechanisms are largely unknown. Sexual activity and mating with a receptive female has recently been shown to reduce the subsequent emotional stress response via activation of the brain oxytocin system. Therefore we investigated the neuronal and hormonal responses to an acute stressor (forced swimming) after mating in male rats. Attenuation of the stress-induced increase of c-fos and CRH mRNA expression within the hypothalamic paraventricular nucleus 4 h after mating revealed that sexual activity reduced neuronal reactivity in this reg... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3052879 Fri, 27 Nov 2009 00:00:00 +0100 3052879 http://www.medworm.com/index.php?rid=3045304&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19945459%26dopt%3DAbstract Authors: Bakker J, Pierman S, González-Martínez D Pheromones have been shown to induce sexually dimorphic responses in LH secretion. Here we asked whether the sexually dimorphic population of kisspeptin neurons in the rostral periventricular area of the third ventricle (RP3V) could relay sexually dimorphic information from the olfactory systems to the GnRH system. Furthermore, we analyzed the effects of aromatase mutation (ArKO) and thus the role of estradiol on RP3V kisspeptin neuronal numbers and on the response of these kisspeptin neurons to same-versus opposite-sex urinary pheromones. Exposure to male but not female urinary odors induced Fos protein in kisspeptin neurons in the RP3V of female wildtype (WT) mice, suggesting that these kisspeptin neurons may be part of the ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3045304 Thu, 26 Nov 2009 00:00:00 +0100 3045304 http://www.medworm.com/index.php?rid=3045305&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19944105%26dopt%3DAbstract In conclusion, transport of horses over short and medium distances leads to increased cortisol release and changes in heart rate and HRV indicative of stress. The degree of these changes is related to the duration of transport. Salivary cortisol is a sensitive parameter to detect transient changes in cortisol release. PMID: 19944105 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3045305 Tue, 24 Nov 2009 00:00:00 +0100 3045305 http://www.medworm.com/index.php?rid=3004720&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19914254%26dopt%3DAbstract Authors: Melloni RH, Ricci LA Considerable public attention has been focused on the issue of youth violence, particularly that associated with drug use. It is documented that anabolic steroid use by teenagers is associated with a higher incidence of aggressive behavior and serious violence, yet little is known about how these drugs produce the aggressive phenotype. Here we discuss work from our laboratory on the relationship between the development and activity of select neurotransmitter systems in the anterior hypothalamus and anabolic steroid-induced offensive aggression using pubertal male Syrian hamsters (Mesocricetus auratus) as an adolescent animal model, with the express goal of synthesizing these data into an cogent neural model of the developmental adaptations that may underli... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3004720 Thu, 12 Nov 2009 00:00:00 +0100 3004720 http://www.medworm.com/index.php?rid=3004723&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19909753%26dopt%3DAbstract Authors: Tachibana T, Khan MS, Matsuda K, Ueda H, Cline MA The purpose of the present study was to determine whether central administration of substance P (SP), a tachykinin neuropeptide, influenced feeding behavior in layer chicks (Gallus gallus). Intracerebroventricular (ICV) injections of 5 nmol SP decreased food intake in 5- and 6-day-old chicks under both ad libitum and 3-h fasting conditions. There are 3 major subtypes of tachykinin receptors, namely, neurokinin 1, 2 and 3 receptors. Injection of neurokinin A and neurokinin B, which are respectively endogenous agonists for neurokinin 2 and 3 receptors, did not suppress feeding behavior in chicks, suggesting that the anorexigenic effect of SP might be mediated by the neurokinin 1 receptor rather than neurokinin 2 and 3 receptors. ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3004723 Tue, 10 Nov 2009 00:00:00 +0100 3004723 http://www.medworm.com/index.php?rid=3004721&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19913019%26dopt%3DAbstract Authors: Saraiva JL, Gonçalves DM, Oliveira RF Morphology and endocrinology were studied in two populations of the peacock blenny Salaria pavo, with different regimes of sexual selection imposed by differences in nest site availability. The peacock blenny is a small, sexually dimorphic benthic fish that presents exclusive paternal care of the clutch and inhabits rocky shores of the Mediterranean and adjacent Atlantic areas. In a population from the Gulf of Trieste (Northern Adriatic sea) inhabiting rocky shores where nest sites are abundant, male-male competition for nests is low, males court females and a low frequency of alternative reproductive tactics (small, parasitic female-mimicking sneaker males that change tactic into nest-holders in subsequent breeding seasons) occurs. C... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=3004721 Tue, 10 Nov 2009 00:00:00 +0100 3004721 http://www.medworm.com/index.php?rid=2981454&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19900453%26dopt%3DAbstract Authors: Kuhn C, Johnson M, Thomae A, Luo B, Simon S, Zhou G, Walker QD Adolescence is the developmental epoch during which children become adults- intellectually, physically, hormonally and socially. Brain development in critical areas is ongoing. Adolescents are risk-taking and novelty-seeking and they weigh positive experiences more heavily and negative experiences less than adults. This inherent behavioral bias can lead to risky behaviors like drug taking. Most drug addictions start during adolescence and early drug-taking is associated with an increased rate of drug abuse and dependence. The hormonal changes of puberty contribute to physical, emotional, intellectual and social changes during adolescence. These hormonal events do not just cause maturation of reproductive function a... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2981454 Fri, 06 Nov 2009 00:00:00 +0100 2981454 http://www.medworm.com/index.php?rid=2981453&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19900454%26dopt%3DAbstract Authors: Hamilton LD, Meston CM The present study examined whether testosterone levels are influenced by being with a sexual and romantic partner after a period of sexual abstinence. Women in long distance relationships (n = 15) provided five saliva samples: at least one week before seeing their partner (and at least 2 weeks since their last visit), the day before seeing their partner, when they were with their partner but prior to engaging in sexual activity, the day after their first sexual activity, and three days after they were separated from their partners. Salivary testosterone was lowest when participants had been away from their partners for at least two weeks and highest the day before they were to see their partners and the day after sexual activity. Results from this study ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2981453 Fri, 06 Nov 2009 00:00:00 +0100 2981453 http://www.medworm.com/index.php?rid=2981452&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19900455%26dopt%3DAbstract Authors: Chen GL, Novak MA, Meyer JS, Kelly BJ, Vallender EJ, Miller GM Gene-environment (GxE) interactions contribute to the development of many neuro-psychiatric disorders. Tryptophan hydroxylase-2 (TPH2) synthesizes neuronal serotonin and is closely related to the hypothalamic-pituitary-adrenal (HPA) axis, while early-life experience is a critical environmental factor programming the HPA axis response to stress. This retrospective study investigated GxE interaction at the TPH2 locus in rhesus monkeys. 28 adult, male rhesus monkeys of Indian origin, either mother-reared or peer-reared as infants, were involved in this study. These monkeys have been previously genotyped for the functional A2051C polymorphism in rhTPH2, and had been physiologically and behaviorally characterized. rhTPH... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2981452 Fri, 06 Nov 2009 00:00:00 +0100 2981452 http://www.medworm.com/index.php?rid=2981451&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19900456%26dopt%3DAbstract Authors: Young AJ, Oosthuizen MK, Lutermann H, Bennett NC In many vertebrate societies, subordinate females exhibit down-regulated reproductive physiologies relative to those of dominants, a condition commonly termed physiological suppression. Research into the causes of physiological suppression has focused principally on the role of the subordinate's social environment (typically the presence of the dominant female and/or an absence of unrelated males within the group), while few studies have considered the additional role that the physical environment may play. Here we present new evidence from wild Damaraland mole-rats, Fukomys damarensis, revealing that physiological suppression among subordinate females eases markedly during the annual rains (a time when ecological constraints on... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2981451 Fri, 06 Nov 2009 00:00:00 +0100 2981451 http://www.medworm.com/index.php?rid=2970753&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19891967%26dopt%3DAbstract Authors: Blas J, Hiraldo F Avian populations are composed of reproductive individuals coexisting in space and time with young, non-breeding conspecifics or "floaters". Despite the fact that first breeding can be delayed for years and can exert profound effects on fitness, many aspects of the behavior, ecology and physiology of young floaters remain poorly understood. By means of combining endocrine, behavioral and life-history information from a population of black kites (Milvus migrans) monitored long-term, we tested several hypotheses suggesting endocrine function as a determinant of floating status. Sexual function in non-breeding males, estimated through determination of systemic testosterone and progesterone levels, was similar to that in reproductively active conspecifics. Floati... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2970753 Mon, 02 Nov 2009 00:00:00 +0100 2970753 http://www.medworm.com/index.php?rid=2963793&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19879277%26dopt%3DAbstract Authors: Rensel MA, Wilcoxen TE, Schoech SJ Stressful conditions during development may have lasting consequences for an animal's lifetime fitness. We investigated the degree to which parental provisioning and nest attendance influenced baseline levels of the stress hormone corticosterone in nestling Florida scrub-jays. Provisioning rates of male and female breeders and nest attendance of female breeders were recorded during focal watches conducted between days 3 and 5 post-hatch. A small blood sample was taken from each nestling on day 11 post-hatch and used to quantify levels of baseline corticosterone. The proportion of time spent by female breeders at a considerable distance from the nest was positively related to nestling corticosterone levels. Nestling corticosterone was also neg... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2963793 Wed, 28 Oct 2009 00:00:00 +0100 2963793 http://www.medworm.com/index.php?rid=2931552&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19854195%26dopt%3DAbstract Authors: Strong MN, Yoneyama N, Fretwell AM, Snelling C, Tanchuck MA, Finn DA Binge drinking, defined as achieving blood ethanol concentrations (BEC) of 80 mg%, has been increasing in adolescents and was reported to predispose later physical dependence. The present experiments utilized an animal model of binge drinking to compare the effect of ethanol "binge" experience during adolescence or adulthood on subsequent ethanol intake in male and female C57BL/6 mice. Adolescent and adult mice were initially exposed to the scheduled high alcohol consumption procedure, which produces BECs that exceed the levels for binge drinking following a 30 min ethanol session every third day. Ethanol intake and BECs were significantly higher in the adolescent (~3 g/kg, 199 mg%) versus adult (~2 g/kg, 135... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2931552 Thu, 22 Oct 2009 00:00:00 +0100 2931552 http://www.medworm.com/index.php?rid=2913293&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19840804%26dopt%3DAbstract In conclusion, brain aromatase availability seems like a probable mechanism to regulate the effects of steroids on the brain circuits underlying the expression of sexual and agonistic displays in S. pavo. PMID: 19840804 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2913293 Thu, 15 Oct 2009 23:00:00 +0100 2913293 http://www.medworm.com/index.php?rid=2905729&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19837072%26dopt%3DAbstract Authors: Pfaus JG, Wilkins MF, Dipietro N, Benibgui M, Toledano R, Rowe A, Couch MC Drugs of abuse comprise several pharmacological classes, including psychomotor stimulants, such as amphetamine and cocaine, and CNS depressants, such as morphine and alcohol. Few studies have examined the effects of those drugs systematically on human sexual behavior, although substantial clinical and epidemiological literatures suggest that drugs in both classes either inhibit sexual responding or can be "prosexual" in certain situations, thereby increasing the potential of risky sexual activity and the spread of sexually transmitted diseases. This paper reviews original data in rats showing that both classes of drug inhibit or disinhibit sexual behavior depending on the animal's baseline level of sexu... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2905729 Wed, 14 Oct 2009 23:00:00 +0100 2905729 http://www.medworm.com/index.php?rid=2905730&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19835877%26dopt%3DAbstract Authors: Mello NK Nicotine and cocaine each stimulate hypothalamic-pituitary-adrenal and -gonadal axis hormones, and there is increasing evidence that the hormonal milieu may modulate the abuse-related effects of these drugs. This review summarizes some clinical studies of the acute effects of cigarette smoking or IV cocaine on plasma drug and hormone levels, and subjective effects ratings. The temporal covariance between these dependent measures was assessed with a rapid (two min) sampling procedure in nicotine-dependent volunteers or current cocaine users. Cigarette smoking and IV cocaine each stimulated a rapid increase in LH and ACTH, followed by gradual increases in cortisol and DHEA. Positive subjective effects ratings increased immediately after initiation of cigarette smoking o... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2905730 Mon, 12 Oct 2009 23:00:00 +0100 2905730 http://www.medworm.com/index.php?rid=2903010&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19833131%26dopt%3DAbstract Authors: Gleason ED, Marler CA In the monogamous and biparental California mouse (Peromyscus californicus), paternal care is critical for maximal offspring survival. Animals form pair bonds and do not engage in extrapair matings, and thus female evaluation of paternal quality during courtship is likely to be advantageous. We hypothesized that male endocrine or behavioral response to courtship interactions would be predictive of future paternal behavior. To test this hypothesis, we formed 20 pairs of California mice, and evaluated their behavior during the first hour of courtship interactions and again following the birth of young. We also collected blood from males at baseline, 1-hr after pairing, 3-weeks paired, and when young were four days old to measure testosterone (T). We found t... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2903010 Sun, 11 Oct 2009 23:00:00 +0100 2903010 http://www.medworm.com/index.php?rid=2891515&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19819241%26dopt%3DAbstract Authors: López HH There is a bi-directionality in hormone-cannabinoid interactions: cannabinoids affect prominent endocrine axes (such as the hypothalamic-pituitary-gonadal), and gonadal hormones modulate cannabinoid effects. This review will summarize recent research on these interactions, with a specific focus upon their implications for motivated behavior. Sexual behavior will serve as a "case study." I will explore the hypothesis that ovarian hormones, in particular estradiol, may serve to release estrous behavior from endocannabinoid inhibition. Hormonal regulation of the endogenous cannabinoid system also affects processes that underlie drug abuse. This review will briefly discuss sex differences in behavioral responses to cannabinoids and explore potential mechanisms by whi... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2891515 Wed, 07 Oct 2009 23:00:00 +0100 2891515 http://www.medworm.com/index.php?rid=2891514&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19819242%26dopt%3DAbstract Authors: Quinones-Jenab V, Jenab S In this review, we summarize literature focused on how progesterone alters cocaine-induced psychomotor, reinforcement, and physiological responses. Clinical studies suggest that progesterone attenuates the subjective effects of cocaine. Similarly, preclinical studies have demonstrated that cocaine-induced reward and psychomotor responses are attenuated after progesterone administration. In rats progesterone also reduces the reinforcement effects of cocaine attenuates acquisition, escalation, reinstatement of cocaine self-administration, and cocaine-seeking behaviors. Progesterone also counteracts the facilitatory effects of estrogen on cocaine self-administration and psychomotor activation. These findings suggest that progesterone has a potential in c... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2891514 Wed, 07 Oct 2009 23:00:00 +0100 2891514 http://www.medworm.com/index.php?rid=2891516&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19818789%26dopt%3DAbstract Authors: Carroll ME, Anker JJ Increasing evidence indicates the presence of sex differences in many aspects of drug abuse. Most studies reveal that females exceed males during the initiation, escalation, extinction, and reinstatement (relapse) of drug-seeking behavior, but males are more sensitive than females to the aversive effects of drugs such as drug withdrawal. Findings from human and animal research indicate that circulating levels of ovarian steroid hormones account for these sex differences. Estrogen (E) facilitates drug-seeking behavior, while progesterone (P) and its metabolite, allopregnanalone (ALLO), counteract the effects of E and reduce drug-seeking. Estrogen and P influence other behaviors that are affiliated with drug abuse such as drug-induced locomotor sensitization... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2891516 Tue, 06 Oct 2009 23:00:00 +0100 2891516 http://www.medworm.com/index.php?rid=2891517&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19818354%26dopt%3DAbstract Authors: Vitousek MN, Mitchell MA, Romero LM, Awerman J, Wikelski M It is unusual for seasonal breeders to frequently skip opportunities for reproduction. We investigated the relationship between physiological state and reproductive decision-making in Galápagos marine iguanas (Amblyrhynchus cristatus), a species in which females typically reproduce biennially, although the proportion of breeding individuals varies significantly across years. Nearly all adult-sized females initiated follicular development prior to the lekking period, but 38% of females resorbed all developing follicles 5-15 days before the start of copulations. Receptive and non-receptive females differed in reproductive hormones during the mate choice period. Testosterone peaked in receptive females immediately pr... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2891517 Mon, 05 Oct 2009 23:00:00 +0100 2891517 http://www.medworm.com/index.php?rid=2866476&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19804778%26dopt%3DAbstract Authors: Ruuskanen S, Laaksonen T The hormonal environment during early development, such as maternally derived androgens in bird eggs, shapes the development and phenotype of the offspring in ways that may have important long-term consequences for behaviour. We studied the effects of yolk androgens on multiple behavioural traits in female and male pied flycatchers (Ficedula hypoleuca) by experimentally elevating androgen levels (testosterone and androstenedione) in the eggs. The birds were housed in a common-garden environment in captivity until full independence, after which their behaviour was tested. We found that androgen-treated males were more likely than control males to explore a novel environment and showed higher activity in the presence of a novel object. In response to a s... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2866476 Thu, 01 Oct 2009 23:00:00 +0100 2866476 http://www.medworm.com/index.php?rid=2866475&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19804779%26dopt%3DAbstract Authors: Starling AP, Charpentier MJ, Fitzpatrick C, Scordato ES, Drea CM Fecal glucocorticoid (fGC) concentrations are reliable, non-invasive indices of physiological stress that provide insight into an animal's energetic and social demands. To better characterize the long-term stressors in adult members of a female-dominant, seasonally breeding species - the ring-tailed lemur (Lemur catta) - we first validated fecal samples against serum samples and then examined the relationship between fGC concentrations and seasonal, social, demographic, genetic, and reproductive variables. Between 1999 and 2006, we collected 1,386 fecal samples from 32 adult, semi-free-ranging animals of both sexes. In males and nonpregnant, nonlactating females, fGC concentrations were significantly elevated dur... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2866475 Thu, 01 Oct 2009 23:00:00 +0100 2866475 http://www.medworm.com/index.php?rid=2866474&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19804780%26dopt%3DAbstract Authors: Amaral VC, Gomes KS, de Souza RL In recent years, there has been a notable interest in studying prey-predator relationships to develop rodent-based models for the neurobehavioral aspects of stress and emotion. However, despite the growing use of transgenic mice and results showing important differences in the behavioral responses of rats and mice, little research has been conducted regarding the responses of mice to predators. The rat exposure test (RET), a recently developed and behaviorally validated prey-predator (rat-mouse) based model, has proven to be a useful tool in evaluating the defensive responses of mice facing rats. To further validate the RET, we investigated the endocrine and behavioral responses of mice exposed to this apparatus. We first constructed a plasma c... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2866474 Thu, 01 Oct 2009 23:00:00 +0100 2866474 http://www.medworm.com/index.php?rid=2866477&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19800885%26dopt%3DAbstract In this study, we considered the effect of both food availability and elevated T on immune function and reproductive behavior in sagebrush lizards, Sceloporus graciosus, to assess how T and energy availability affect these trade-offs. We experimentally manipulated diet (via supplemental feedings) and T (via dermal patches) in males from a natural population. We determined innate immune response by calculating the bacterial killing capability of collected plasma exposed to E. coli ex vivo. We measured reproductive behavior by counting the number of courtship displays produced in a 20-min sampling period. We observed an interactive effect of food availability and T-patch on immune function, with food supplementation increasing immunity in T-patch lizards. Additionally, T increased courtship ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2866477 Wed, 30 Sep 2009 23:00:00 +0100 2866477 http://www.medworm.com/index.php?rid=2866478&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19800345%26dopt%3DAbstract Authors: Van Hout AJ, Eens M, Balthazart J, Pinxten R In many temperate zone songbird species males only produce song during the breeding season, when plasma testosterone (T) levels are high. Males of some species sing throughout the year, even when T levels are low, indicating a dissociation between high T levels and song rate. Given that few studies have taken advantage of these species, we compare here song traits expressed under high versus low T concentrations and we study the role of testosterone in adult song learning in the European Starling, an open-ended learner in which repertoire size dramatically increases with age. We performed a detailed comparison of song complexity and song rate between fall and spring in 6-years-old intact male European starlings. In parallel, we inve... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2866478 Tue, 29 Sep 2009 23:00:00 +0100 2866478 http://www.medworm.com/index.php?rid=2866480&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19799904%26dopt%3DAbstract Authors: Stolzenberg DS, Zhang KY, Luskin K, Ranker L, Bress J, Numan M A body of evidence supports the idea that the mesolimbic dopamine (DA) system modulates the natural increase in responsiveness female rats show toward offspring (biological or foster) at birth. In the absence of the full hormonal changes associated with pregnancy and birth, female rats do not show immediate responsiveness toward foster offspring. Activation of the mesolimbic DA system can produce an immediate onset of maternal behavior in these females. For example, female rats that are hysterectomized and ovariectomized on day 15 of pregnancy (15HO) and presented with pups 48 hours later normally show maternal behavior after 2-3 days of pup exposure, but will show maternal behavior on day 0 of testing after microi... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2866480 Mon, 28 Sep 2009 23:00:00 +0100 2866480 http://www.medworm.com/index.php?rid=2866479&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19799905%26dopt%3DAbstract We examined the role of ARs in regulating territorial aggression in captive song sparrows under short and long day conditions as well as just prior to, and at the start of the breading season in freely living birds using the nonsteroidal antiandrogen flutamide to block AR function. Birds were implanted with either empty or drug filled silastic implants for 18 to 42 days and then challenged with a novel male decoy to assess the individual birds level of male-male aggression. Freely living birds remained on their home territory and underwent a Simulated Territorial Intrusion, whereas laboratory held birds were assessed using a Laboratory Simulated Territorial Intrusion and remained in their home cage. Experimental treatment of male song sparrows decreased aggressive behavior during the pre-b... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2866479 Mon, 28 Sep 2009 23:00:00 +0100 2866479 http://www.medworm.com/index.php?rid=2852191&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19786031%26dopt%3DAbstract This article reviews sex differences in opiate analgesic and related processes as part of a Special Issue in Hormones and Behavior. The research findings on sex differences are organized in the following manner: a) systemic opioid analgesia across mu, delta and kappa opioid receptor subtypes and drug efficacy at their respective receptors, b) effects of the activational and organizational roles of gonadal steroid hormones and estrus phase on systemic analgesic responses, c) sex differences in spinal opioid analgesia, d) sex differences in supraspinal opioid analgesia and gonadal hormone effects, e) the contribution of genetic variance to analgesic sex differences, f) sex differences in opioid-induced hyperalgesia, g) sex differences in tolerance and withdrawal-dependence effects, and h) im... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2852191 Thu, 24 Sep 2009 23:00:00 +0100 2852191 http://www.medworm.com/index.php?rid=2852190&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19786032%26dopt%3DAbstract Authors: McEwen BS, Wingfield JC PMID: 19786032 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2852190 Thu, 24 Sep 2009 23:00:00 +0100 2852190 http://www.medworm.com/index.php?rid=2852189&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19786033%26dopt%3DAbstract Authors: Pearson RM, Lightman SL, Evans J Previous research suggests that female sex hormones can increase the sensitivity of women's emotion processing systems. The largest rises in sex hormone levels in a woman's life are from early to late pregnancy. The current study, therefore, investigated whether changes in emotion processing are seen across pregnancy. Hypervigilant emotion processing has been implicated in the aetiology of anxiety. Therefore enhanced emotion processing across pregnancy has implications for women's vulnerability to anxiety. Ability to encode facial expressions of emotion was assessed in 101 women during early pregnancy and again in 76 of these women during late pregnancy. Symptoms of anxiety were measured using a clinical interview (The CIS-R). Consistent with p... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2852189 Thu, 24 Sep 2009 23:00:00 +0100 2852189 http://www.medworm.com/index.php?rid=2852193&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19782685%26dopt%3DAbstract Authors: Falsone K, Jenni-Eiermann S, Jenni L The specific role of the glucocorticoid hormone corticosterone in regulating the migratory stages of flight and refuelling in free-living migrants is as yet poorly studied, because these stages are difficult to identify in the field. Night migrating songbirds provide an excellent model to investigate how corticosterone correlates with behaviour and physiology because they fly during the night and rest and forage during the day. We measured baseline corticosterone and the adrenocortical response to restraint in 9 free-ranging songbird species: 3 night migrating species, 3 day migrating species and 3 day migrating irruptive species. Baseline corticosterone of night migrants was higher in birds caught out of nocturnal migration than in birds r... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2852193 Wed, 23 Sep 2009 23:00:00 +0100 2852193 http://www.medworm.com/index.php?rid=2852192&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19782686%26dopt%3DAbstract Authors: Pruis TA, Roalf DR, Janowsky JS Sex hormones have actions in brain regions important for emotion, including the amygdala and prefrontal cortex. Previous studies have shown that cyclic sex hormones and hormone therapy after menopause modify responses to emotional events. Thus, this study examined whether hormone therapy modified emotion-induced brain activity in older women. Functional magnetic resonance imaging (fMRI), behavioral ratings (valence and arousal), and recognition memory were used to assess responses to emotionally laden scenes in older women currently using hormone therapy (HT) and women not currently using hormone therapy (NONE). We hypothesized that hormones would affect the amount or persistence of emotion-induced brain activity in the amygdala and ventrolatera... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2852192 Wed, 23 Sep 2009 23:00:00 +0100 2852192 http://www.medworm.com/index.php?rid=2836487&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19778539%26dopt%3DAbstract Authors: Uchoa ET, da Silva LE, de Castro M, Antunes-Rodrigues J, Elias LL Glucocorticoids have major effects on food intake, as demonstrated by the decrease of food intake following adrenalectomy (ADX), however the mechanisms leading to these effects are not well understood. Oxytocin (OT) has been shown to reduce food intake. We evaluated the effects of glucocorticoids on OT neuron activation and OT mRNA expression in the hypothalamic paraventricular (PVN) and supraoptic (SON) nuclei induced by feeding. We also evaluated the effect of pretreatment with OT-receptor antagonist ([d(CH(2))(5),Tyr(Me)(2),Orn(8)]-vasotocin, OVT) on food intake in ADX rats. Fos/OT neurons in the posterior parvocellular subdivision of the PVN were increased after refeeding, with a higher number in the ADX gro... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2836487 Sun, 20 Sep 2009 23:00:00 +0100 2836487 http://www.medworm.com/index.php?rid=2825287&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19769977%26dopt%3DAbstract Authors: Kanayama G, Hudson JI, Pope HG The anabolic-androgenic steroids (AAS) are a family of hormones that includes testosterone and its derivatives. These substances have been used by elite athletes since the 1950s, but they did not become widespread drugs of abuse in the general population until the 1980s. Thus, knowledge of the medical and behavioral effects of illicit AAS use is still evolving. Surveys suggest that many millions of boys and men, primarily in Western countries, have abused AAS to enhance athletic performance or personal appearance. AAS use among girls and women is much less common. Taken in supraphysiologic doses, AAS show various long-term adverse medical effects, especially cardiovascular toxicity. Behavioral effects of AAS include hypomanic or manic symptoms, s... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2825287 Thu, 17 Sep 2009 23:00:00 +0100 2825287 http://www.medworm.com/index.php?rid=2825286&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19769978%26dopt%3DAbstract In conclusion, cocaine sensitization promotes the acquisition of cocaine self-administration in female rats. Furthermore, prior cocaine experience is more powerful than estradiol at enhancing acquisition, while estradiol enhances intake of cocaine after acquisition of self-administration. PMID: 19769978 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2825286 Thu, 17 Sep 2009 23:00:00 +0100 2825286 http://www.medworm.com/index.php?rid=2825285&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19769979%26dopt%3DAbstract Authors: Attila M, Oksala R, Agmo A In Experiment 1 castrated male rats were implanted with a Silastic capsule containing either E or cholesterol (CHOL) 35 days after castration. They were then tested for sexual incentive motivation and copulatory behaviors every 5th day for 3 weeks. None of the treatments affected sexual incentive motivation. After the last test, all subjects were implanted with DHT-containing Silastic capsules, and tests continued for another 3 weeks. While E + DHT enhanced sexual incentive motivation and copulatory behavior, DHT alone failed to do so. In Experiment 2 the aromatase inhibitor fadrozole (F) was combined with testosterone (T). T restored all behaviors to the level seen in intact rats, and F significantly reduced these effects. In fact, T + F was not dif... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2825285 Thu, 17 Sep 2009 23:00:00 +0100 2825285 http://www.medworm.com/index.php?rid=2812604&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19761768%26dopt%3DAbstract Authors: Brown SL, Fredrickson BL, Wirth MM, Poulin MJ, Meier EA, Heaphy ED, Cohen MD, Schultheiss OC PMID: 19761768 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2812604 Sun, 13 Sep 2009 23:00:00 +0100 2812604 http://www.medworm.com/index.php?rid=2801122&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19751736%26dopt%3DAbstract Authors: Tibbetts EA, Izzo AS There has been increasing interest in the mechanisms that mediate behavioral and physiological plasticity across individuals with similar genotypes. Some of the most dramatic plasticity is found within and between social insect castes. For example, Polistes wasp queens can nest alone, dominate a group of cooperative queens, or act as worker-like subordinates who rarely reproduce. Previous work suggests that condition-dependent endocrine responses may play a role in plasticity between castes in the hymenoptera. Here, we test whether condition-dependent endocrine responses influence plasticity within castes in the wasp Polistes dominulus. We experimentally manipulate juvenile hormone (JH) titers in nest-founding queens and assess whether JH mediates variatio... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2801122 Thu, 10 Sep 2009 23:00:00 +0100 2801122 http://www.medworm.com/index.php?rid=2801121&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19751737%26dopt%3DAbstract Authors: Lord LD, Bond J, Thompson RR The ability of steroid hormones to rapidly influence cell physiology through non-genomic mechanisms raises the possibility that these molecules may play a role in the dynamic regulation of social behavior, particularly in species in which social stimuli can rapidly influence circulating steroid levels. We therefore tested if testosterone(T), which increases in male goldfish in response to sexual stimuli, can rapidly influence approach responses towards females. Injections of T stimulated approach responses towards the visual cues of females 30-45 min after the injection, but did not stimulate approach responses towards stimulus males or affect general activity, indicating the effect is stimulus-specific and not a secondary consequence of increased ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2801121 Thu, 10 Sep 2009 23:00:00 +0100 2801121 http://www.medworm.com/index.php?rid=2801120&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19751738%26dopt%3DAbstract This study contributes to the growing evidence that modulating baseline CORT mediates parental care and self-maintenance activities in birds, and thus may serves as a mechanism for balancing current reproductive success with survival. PMID: 19751738 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2801120 Thu, 10 Sep 2009 23:00:00 +0100 2801120 http://www.medworm.com/index.php?rid=2778822&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19733571%26dopt%3DAbstract Authors: Evans SM, Foltin RW Stimulant abuse continues to be a growing problem among women. Over the last 10-15 years, an increasing number of studies have focused on factors that may be implicated in stimulant abuse in women as compared to men, including the role of hormonal fluctuations across the menstrual cycle. Numerous preclinical studies have documented that female rodents are more sensitive than male rodents to the behavioral effects of stimulant administration and the hormone estradiol is involved in the enhanced response to stimulants observed in females. In contrast, fewer studies have been conducted in humans and non-human primates addressing the role of sex and gonadal hormones on the effects of cocaine. This review paper presents a recent update on data collected in our H... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2778822 Wed, 02 Sep 2009 23:00:00 +0100 2778822 http://www.medworm.com/index.php?rid=2778823&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19733173%26dopt%3DAbstract Authors: Gorzalka BB, Hill MN, Chang SC The putative role of the endocannabinoid system and the effects of cannabis use in male and female sexual functioning are summarized. The influence of cannabis intake on sexual behavior and arousability appear to be dose-dependent in both men and women, although women are far more consistent in reporting facilitatory effects. Furthermore, evidence from nonhuman species indicate somewhat more beneficial than debilitating effects of cannabinoids on female sexual proceptivity and receptivity while suggesting predominantly detrimental effects on male sexual motivation and erectile functioning. Data from human and nonhuman species converge on the ephemeral nature of THC-induced testosterone decline. However, it is clear that cannabinoid-induced inhibi... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2778823 Tue, 01 Sep 2009 23:00:00 +0100 2778823 http://www.medworm.com/index.php?rid=2769152&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19729013%26dopt%3DAbstract Authors: Hanson KC, Abizaid A, Cooke SJ By definition, parental care behaviors increase offspring survival, and individual fitness, at some cost to the parent. In smallmouth bass (Micropterus dolomieu), parental males provide sole care for the developing brood that includes an increase in activity during brood defense and decreased foraging resulting in a decline in endogenous energy reserves. No mechanisms have been proposed for cessation of voluntary foraging, though regulation of appetite hormones such as ghrelin have been documented to affect feeding behavior in other fishes. We documented baseline fluctuations in plasma ghrelin concentrations across parental care. Plasma ghrelin concentrations were lowest during the early stages of parental care before increasing as the brood deve... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2769152 Sun, 30 Aug 2009 23:00:00 +0100 2769152 http://www.medworm.com/index.php?rid=2753124&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19716370%26dopt%3DAbstract Authors: Gutzler SJ, Karom M, Erwin WD, Albers HE Seasonal changes in the length of the daily photoperiod induce significant changes in social behavior. Hamsters housed in winter-like short photoperiods (SP) can express significantly higher levels of aggression than hamsters housed in long photoperiods (LP) that mimic summer. The mechanisms responsible for increasing aggressiveness in SP-exposed female hamsters are not well understood but may involve seasonal changes in the endocrine system. In experiment 1, the effects of SP exposure on the circulating levels of three adrenal hormones were determined. Short photoperiod exposure was found to significantly depress the circulating levels of cortisol and the adrenal androgen dehydropiandrosterone (DHEA) but significantly increased the cir... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2753124 Tue, 25 Aug 2009 23:00:00 +0100 2753124 http://www.medworm.com/index.php?rid=2744457&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19712675%26dopt%3DAbstract Authors: Van Belle S, Estrada A, Ziegler TE, Strier KB We investigated the social and hormonal mechanisms underlying male reproductive strategies in two multimale-multifemale groups of black howler monkeys (Alouatta pigra) during a 14-month study in Palenque National Park, Mexico. Fecal glucocorticoid (fGC) and androgen (fA) levels were analyzed for 343 fecal samples collected from 14 males during their presence in the study groups. Neither immigrating males nor resident males that remained in the group had elevated fGC and fA levels during 11 observed male migration events, suggesting that competition over group membership was not associated with variation in the fecal hormonal levels of males. Instead, fGC and fA levels were significantly higher in males who maintained a central posi... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2744457 Sun, 23 Aug 2009 23:00:00 +0100 2744457 http://www.medworm.com/index.php?rid=2744456&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19712676%26dopt%3DAbstract Authors: Beehner JC, Gesquiere L, Seyfarth RM, Cheney DL, Alberts SC, Altmann J Despite significant advances in our knowledge of how testosterone mediates life-history trade-offs, this research has primarily focused on seasonal species. We know comparatively little about the relationship between testosterone and life-history stages for non-seasonally breeding species. Here we examine testosterone profiles across the lifespan of males from three non-seasonally breeding primates: yellow baboons (Papio cynocephalus or P. hamadryas cynocephalus), chacma baboons (Papio ursinus or P. h. ursinus), and geladas (Theropithecus gelada). First, we predict that testosterone profiles will track the reproductive profiles of each taxon across their respective breeding years. Second, we evaluate age-re... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2744456 Sun, 23 Aug 2009 23:00:00 +0100 2744456 http://www.medworm.com/index.php?rid=2738445&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19703457%26dopt%3DAbstract Authors: Paus T, Nawaz-Khan I, Leonard G, Perron M, Pike GB, Pitiot A, Richer L, Susman E, Veillette S, Pausova Z Here we examined sex differences in the volumes of grey and white matter, and in grey-matter "density", in a group of typically developing adolescents participating in the Saguenay Youth Study (n=419; 12 - 18 years). In male adolescents, we also investigated the role of a functional polymorphism in androgen-receptor gene (AR) in moderating the effect of testosterone on volumes of grey and white matter and grey-matter density. Overall, both absolute and relative volumes of white matter were larger in male vs. females adolescents. The relative grey-matter volumes were slightly larger in female than male adolescents and so was the grey-matter density in a large number of corti... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2738445 Thu, 20 Aug 2009 23:00:00 +0100 2738445 http://www.medworm.com/index.php?rid=2731001&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19699202%26dopt%3DAbstract Authors: Muñoz-Abellán C, Daviu N, Rabasa C, Nadal R, Armario A A single exposure to a cat or cat odors has been reported by some groups to induce contextual and auditory fear conditioning and long-lasting changes in anxiety-like behaviour, but there is no evidence for parallel changes in biological stress markers. In the present study we demonstrated in male rats that exposure to a novel environment containing a cloth impregnated with cat fur odor resulted in avoidance of the odor, lower levels of activity and higher pituitary-adrenal (PA) response as compared to those exposed to the novel environment containing a clean cloth, suggesting increased levels of stress in the former animals. When re-exposed 9 days later to the same environment with a clean cloth, previously cat f... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2731001 Tue, 18 Aug 2009 23:00:00 +0100 2731001 http://www.medworm.com/index.php?rid=2731000&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19699203%26dopt%3DAbstract Authors: Alexander GM, Wilcox T, Farmer ME The physiological significance of hormonal changes in early postnatal life is emerging, but the behavioral significance in humans is unknown. As a first test of the relationship between hormones and behavior in early infancy we measured digit ratios and salivary hormone levels in forty-one male and female infants (3-4 months of age) who watched a video depicting stimuli differentially preferred by older males and females (toys, groups). An eye-tracker measured visual fixations and looking times. In female infants, hormones were unrelated to visual preferences. In male infants, higher androgen levels predicted stronger preferences for male-typical stimuli. These data provide the first evidence for a role for hormones in emerging sex-linked beha... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2731000 Tue, 18 Aug 2009 23:00:00 +0100 2731000 http://www.medworm.com/index.php?rid=2709685&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19682449%26dopt%3DAbstract We examined patterns in baseline (BL) and stress induced (level following a standard capture restraint protocol; SI) levels of PRL and CORT for breeding mourning doves (Zenaida macroura). We determined whether the relationship of adult condition and parental effort to hormone levels in wild birds were consistent with life-history predictions. Both BL PRL and BL CORT level in adults were positively related to nestling weight at early nestling ages, consistent with the prediction of a positive relationship of hormone levels to current parental effort of adults and associated increased energy demand. Results are consistent with the two hormones acting together at baseline levels to limit negative effects of CORT on reproduction while maintaining beneficial effects such as increased foraging f... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2709685 Mon, 10 Aug 2009 23:00:00 +0100 2709685 http://www.medworm.com/index.php?rid=2704124&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19679132%26dopt%3DAbstract In conclusion, the sexual behavior of males contributes to the maintenance of a high LH pulsatility up to 24 h after introduction into a group of anovulatory goats. PMID: 19679132 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2704124 Sun, 09 Aug 2009 23:00:00 +0100 2704124 http://www.medworm.com/index.php?rid=2692760&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19665463%26dopt%3DAbstract Authors: Georgescu M, Sabongui C, Del Corpo A, Marsan L, Pfaus JG Vaginocervical stimulation (VCS) induces the immediate early gene product Fos in the ventromedial hypothalamus (VMH) of female rats. However, this induction is lower in ovariectomized rats that receive estradiol benzoate (EB) and progesterone (P) relative to an oil vehicle. We have observed that a substantial proportion of cells activated in the VMH by VCS stain for glutamate, and infusions of glutamate or its selective receptor agonists to the VMH inhibit both appetitive and consummatory sexual behaviors in females. This raises the possibility that VCS activates an inhibitory glutamate system in the VMH, and that ovarian steroids blunt the activation, although it is not known whether EB or P, alone or in combination, le... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2692760 Wed, 05 Aug 2009 23:00:00 +0100 2692760 http://www.medworm.com/index.php?rid=2692762&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19664636%26dopt%3DAbstract This study was designed to examine the possible causal relationships between prolactin and male parenting behaviors, reproductive hormones, and physical changes in cooperatively breeding common marmosets, Callithrix jacchus. Fifteen parentally experienced fathers were studied over three consecutive infant care periods during two weeks prior and three weeks following their mates' parturition under three treatment conditions: normal control pregnancy, decreased prolactin and elevated prolactin. The treatments significantly altered the serum prolactin levels in the fathers. Using three methods of determining a father's level of parental care: infant carrying, family effort and responsiveness to infant stimulus tests, we found that only the male response to infant stimuli was altered by the ho... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2692762 Mon, 03 Aug 2009 23:00:00 +0100 2692762 http://www.medworm.com/index.php?rid=2692761&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19664637%26dopt%3DAbstract This study addresses the question of whether indicators of male reproductive effort are associated with variations in salivary testosterone levels in a polygynous population of agriculturists in rural Senegal. We first show that pair-bonding and/or transition to fatherhood is associated with T profiles: married fathers (N = 53) have lower morning T levels than unmarried non-fathers (N = 28). Second, among fathers, individual differences in parenting effort, as well as variations in mating effort, predict morning T levels in fathers. Indeed, men highly investing in parental care show lower morning T levels. Moreover, among men under 40, polygynous men show higher morning T levels than monogamous men. Taken together with previous results in monogamous settings, these findings suggest that th... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2692761 Mon, 03 Aug 2009 23:00:00 +0100 2692761 http://www.medworm.com/index.php?rid=2671680&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19651128%26dopt%3DAbstract Authors: Solomon MB, Karom MC, Norvelle A, Markham CA, Erwin WD, Huhman KL It has been widely reported that gonadal hormones influence the display of aggression in Syrian hamsters; conversely, much less is known about whether gonadal hormones modulate submissive/defensive behaviors in these animals. Following social defeat, male hamsters no longer display normal territorial aggression but instead display submissive/defensive behavior in the presence of a smaller opponent, a phenomenon we have termed conditioned defeat (CD). The purpose of the present study was to examine the effect of gonadal hormones on the display of CD in male hamsters. In Experiment 1, males were castrated or sham-operated. The castrated males were significantly more submissive following social defeat relative to t... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2671680 Thu, 30 Jul 2009 23:00:00 +0100 2671680 http://www.medworm.com/index.php?rid=2671679&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19651129%26dopt%3DAbstract Authors: Kuzawa CW, Gettler L, Muller MN, McDade TW, Feranil AB In species with a high level of paternal care, including humans, testosterone (T) is believed to help mediate the trade-off between parenting and mating effort. This hypothesis is supported by the observation of lower T in pairbonded men or fathers compared to single, non-fathers; however, prior work has highlighted population variation in the association between T and pairbonding or fatherhood status. Here we evaluate this hypothesis in a large (n=890), representative birth cohort of young men (age range 20.5-22.5 years) living in Cebu City, the Philippines. Bioavailable T was measured in saliva collected prior to bed and immediately upon waking the following morning. Plasma T and luteinizing hormone (LH) were measured in... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2671679 Thu, 30 Jul 2009 23:00:00 +0100 2671679 http://www.medworm.com/index.php?rid=2671681&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19647742%26dopt%3DAbstract Authors: Salazar VL, Stoddard PK Sexually-selected communication signals can be used by competing males to settle contests without incurring the costs of fighting. Steroid regulation of these signals can render them as reliable indicators of a male's physiological state. We investigated how plasticity in electrocommunication signals is driven by social competition for mates, mediated by steroid hormones, and subject to the effects of past social experience. We measured the electric waveform's amplitude and duration and steroid hormone levels of male gymnotiform electric fish (Brachyhypopomus gauderio) following week-long periods of social isolation, and low or high social competition. To quantify the effect of social history on the modulation of the electric signal, six groups of six m... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2671681 Wed, 29 Jul 2009 23:00:00 +0100 2671681 http://www.medworm.com/index.php?rid=2671682&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19646986%26dopt%3DAbstract In this study we assessed if prenatal exposure to yolk testosterone can influence auditory learning in embryos of Northern bobwhite quail (Colinus virginianus). We experimentally enhanced testosterone concentrations in bobwhite quail eggs prior to incubation. The embryos from these T-treated eggs as well as control embryos that had received the vehicle-only or were non-treated were exposed to an individual bobwhite hen's maternal call for 120 min over the course of the day prior to hatching. All chicks were tested at 24 hr following hatching for their auditory preference between the familiar bobwhite maternal call versus an unfamiliar bobwhite maternal call. T-treated chicks spent significantly more time in proximity to the familiar call compared to the unfamiliar call and also showed shor... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2671682 Tue, 28 Jul 2009 23:00:00 +0100 2671682 http://www.medworm.com/index.php?rid=2671683&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19646448%26dopt%3DAbstract Authors: Camacho FJ, García-Horsman P, Paredes RG The ability to control or pace the sexual interaction has important physiological and behavioral consequences for the female rat. Paced mating favors reproduction and induces a positive affective state as revealed by conditioned place preference (CPP). In the present experiment we evaluated: 1) If paced mating induces CPP in naturally cycling females; 2) If females developed a positive affective state if they paced the sexual interaction through a 1- or a 3-hole pacing chamber; 3) If females that mate with the same male without pacing the sexual interaction develop CPP. In the first experiment intact females were divided in 4 different groups; 2 paced the sexual interaction until receiving 1 or 3 ejaculations; the other 2 groups ma... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2671683 Mon, 27 Jul 2009 23:00:00 +0100 2671683 http://www.medworm.com/index.php?rid=2647972&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19632235%26dopt%3DAbstract In this study we further investigated this hypothesis by evaluating the long-term effects of a neonatal exposure to low (33 mg/l) and high (100mg/l) doses of corticosterone during the first 10 days of life in outbred CD-1 mice through supplementation in the maternal drinking water. Offspring attentional set-shifting abilities, central neurotrophic regulation and levels of natural auto-antibodies (na-Abs) directed to serotonin (SERT) and dopamine (DAT) transporters were assessed in adulthood. While low levels of neonatal corticosterone improved adult cognitive abilities and increased na-Abs levels directed to SERT, high doses of neonatal corticosterone reduced hippocampal BDNF levels and na-Abs directed to DAT. These findings confirm and extend our previous findings, supporting the view tha... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2647972 Wed, 22 Jul 2009 23:00:00 +0100 2647972 http://www.medworm.com/index.php?rid=2647973&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19631212%26dopt%3DAbstract Authors: Wang VC, Neese SL, Korol DL, Schantz SL The current study examined effects of chronic estradiol replacement on a prefrontally-mediated working memory task at different ages in a rodent model. Ovariectomized young, middle-aged, and old Long-Evans rats were given 5% or 10% 17beta estradiol in cholesterol vehicle via Silastic implants and tested on an operant delayed spatial alternation task (DSA). The two estradiol exposed groups did not perform as well as the vehicle control group did. Deficits were present at all but the longest delay, where all groups including the vehicle control group performed poorly. Surprisingly, there was not a significant effect of age or an age by estradiol interaction, despite the fact that old rats had longer latencies to respond after both correct ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2647973 Mon, 20 Jul 2009 23:00:00 +0100 2647973 http://www.medworm.com/index.php?rid=2622698&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19616550%26dopt%3DAbstract Authors: Scotti MA, Schmidt KL, Newman AE, Bonu T, Soma KK, Demas GE The gonadal hormone testosterone (T) regulates aggression across a wide range of vertebrate species. Recent evidence suggests that the adrenal prohormone dehydroepiandrosterone (DHEA) may also play an important role in regulating aggression. DHEA can be converted into active sex steroids, such as T and estradiol (E(2)), within the brain. Previous studies show that circulating DHEA levels display diurnal rhythms and that melatonin increases adrenal DHEA secretion in vitro. Here we examined serum DHEA and T levels in long-day housed Siberian hamsters (Phodopus sungorus), a nocturnal species in which melatonin treatment increases aggression. In Experiment 1, serum DHEA and T levels were measured in adult male hamsters du... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2622698 Wed, 15 Jul 2009 23:00:00 +0100 2622698 http://www.medworm.com/index.php?rid=2622699&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19616002%26dopt%3DAbstract This study does not support the hypothesis that prenatal DEX exposure leads to depression-like symptoms in rats, despite the observed sex-specific programming effect on HPA axis. It does however emphasise the importance of rearing environment on adult cognitive performances. PMID: 19616002 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2622699 Tue, 14 Jul 2009 23:00:00 +0100 2622699 http://www.medworm.com/index.php?rid=2622701&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19615369%26dopt%3DAbstract Authors: Finn DA, Beckley EH, Kaufman KR, Ford MM Alcoholism is a complex disorder that represents an important contributor to health problems worldwide and that is difficult to encompass with a single preclinical model. Additionally, alcohol (ethanol) influences the function of many neurotransmitter systems, with the interaction at gamma-aminobutyric acid(A) (GABA(A)) receptors being integral for ethanol's reinforcing and several withdrawal-related effects. Given that some steroid derivatives exert rapid membrane actions as potent positive modulators of GABA(A) receptors and exhibit a similar pharmacological profile to that of ethanol, studies in the laboratory manipulated GABAergic steroid levels and determined the impact on ethanol's rewarding- and withdrawal-related effects. Manipu... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2622701 Mon, 13 Jul 2009 23:00:00 +0100 2622701 http://www.medworm.com/index.php?rid=2622700&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19615370%26dopt%3DAbstract Authors: Sánchez P, Torres JM, Olmo A, O'Valle F, Ortega E Environmental stress conditions are important factors in human health and should be considered in the development of appropriate health policies, since they have been associated with psychological disorders and even with death. A link between stress and changes in 3alpha,5alpha-reduced neurosteroids has been reported. Steroid 5alpha-Reductase (5alpha-R) is the rate-limiting enzyme in the biosynthesis of 3alpha,5alpha-reduced neurosteroids. Using reverse transcription-polymerase chain reaction and immunohistochemistry, 5alpha-R isozymes (5alpha-R1 and 5alpha-R2) mRNA and protein levels were detected in prefrontal cortex of male and female rats after these underwent environmental stresses, i.e., excessive heat, artificial li... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2622700 Mon, 13 Jul 2009 23:00:00 +0100 2622700 http://www.medworm.com/index.php?rid=2598853&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19591832%26dopt%3DAbstract Authors: Kou R, Chou SY, Chen SC, Huang ZY Our previous study [Kou et al., 2008. Juvenile hormone levels are increased in winners of cockroach fights. Horm. Behav. 52, 252-260] showed that the basic principle of the challenge hypothesis (hormone levels can respond to social stimuli to modulate aggression in vertebrates] could be applied to juvenile hormone (JH) levels and aggression in the lobster cockroach Nauphoeta cinerea. In that study, 80- to 85-day-old socially naïve males were used, as fighting is much more easily initiated in these older animals than in younger males, and JH III levels in the dominant were found to be significantly increased after an encounter compared to before the encounter and were significantly higher than those in the subordinates. In N. cinerea, newl... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2598853 Mon, 06 Jul 2009 23:00:00 +0100 2598853 http://www.medworm.com/index.php?rid=2598852&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19591833%26dopt%3DAbstract Authors: Charlier TD, Underhill C, Hammond GL, Soma KK In birds, corticosteroid-binding globulin (CBG) binds corticosterone, progesterone and testosterone. The concentration of each ligand can alter the binding of the other ligands through competitive interactions. Thus, an increase in corticosterone or progesterone may displace testosterone bound to CBG, leading to an increase in bioactive free testosterone levels without affecting total testosterone levels in the circulation. Aggressive interactions increase plasma total testosterone levels in some birds but not in others. Here, we tested the hypothesis that aggressive encounters in the late breeding season would not increase total testosterone levels in plasma, but would alter CBG, total corticosterone or total progesterone levels i... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2598852 Mon, 06 Jul 2009 23:00:00 +0100 2598852 http://www.medworm.com/index.php?rid=2581390&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19576896%26dopt%3DAbstract Authors: Fudge MA, Kavaliers M, Baird JP, Ossenkopp KP Estrogen receptor activation has been shown to reduce body weight and produce a conditioned reduction in food intake in male rats that is putatively mediated by estradiol's suggested aversive effects. Evidence has shown that the selective estrogen receptor modulator tamoxifen used in the prevention and treatment of breast cancer may also produce a change in food intake and body weight, which are known to impact cancer development and survival. The purpose of the present study was to examine whether tamoxifen produces a conditioned reduction in intake similar to estradiol by producing a conditioned aversion. A one bottle lickometer test was used to examine conditioned changes in sucrose drinking, while the taste reactivity test was ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2581390 Tue, 30 Jun 2009 23:00:00 +0100 2581390 http://www.medworm.com/index.php?rid=2581389&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19576897%26dopt%3DAbstract Authors: Saaristo M, Craft JA, Lehtonen KK, Lindström K Endocrine disrupting chemicals (EDCs) are a widely studied group of chemicals that interfere with the endocrinology of organisms. So far, few studies have demonstrated the effect of EDCs on the reproductive behaviour of aquatic wildlife. Here we show that sand goby males (Pomatoschistus minutus) success in mating competition greatly decreases after an exposure for 7 to 24 days to 17alpha-ethinyl estradiol (EE2, measured concentration 4 ng L(-1)). The sand goby exhibits a polygynous mating system with male parental care, in which males compete for nest sites and females. The aim of this study was to test how EE2 exposure affects the ability of males to compete for breeding resources, i.e. nest sites and mates. First, EE2 expos... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2581389 Tue, 30 Jun 2009 23:00:00 +0100 2581389 http://www.medworm.com/index.php?rid=2561712&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19560466%26dopt%3DAbstract This study examined the role of selective estrogen receptor agonists of ERalpha, ERbeta, and GPR30 in the enhancement of spatial learning on a DMP task by comparing continuous estradiol replacement with continuous administration of PPT (an agonist of ERalpha), DPN (an agonist of ERbeta), or G-1 (an agonist of GPR30) relative to gonadally intact and ovariectomized vehicle-treated controls. It was found that ovariectomy impaired acquisition on this task, whereas all ER selective agonists restored the rate of acquisition to that of gonadally intact controls. These data suggest that estradiol can work through any of several estrogen receptors to enhance the rate of acquisition on this task. PMID: 19560466 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2561712 Wed, 24 Jun 2009 23:00:00 +0100 2561712 http://www.medworm.com/index.php?rid=2561713&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19559704%26dopt%3DAbstract We examined effects of age and sexual experience on serum hormones (total testosterone, free testosterone, estradiol, LH) and on numbers of androgen receptor (AR) and estrogen receptor alpha (ERalpha) immunoreactive cells in the hypothalamus. Extensive sexual experience was given to male rats at 4 months of age. Rats were euthanized at either 4 months (young) or 12 months (middle-aged (MA)). Comparable sexually naïve male rats were handled and placed into the testing arena but did not receive any sexual experience. Thus, we had four groups: young-naïve, young-experienced, MA-naïve and MA-experienced. Serum hormone levels were assayed, and numbers of AR and ERalpha cells were quantified stereologically in the medial preoptic nucleus (MPN) and the anteroventral periventricular... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2561713 Tue, 23 Jun 2009 23:00:00 +0100 2561713 http://www.medworm.com/index.php?rid=2532905&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19539629%26dopt%3DAbstract Authors: Kittilsen S, Schjolden J, Beitnes-Johansen I, Shaw JC, Pottinger TG, Sørensen C, Braastad BO, Bakken M, Overli O Within animal populations, genetic, epigenetic and environmental factors interact to shape individual neuroendocrine and behavioural profiles, conferring variable vulnerability to stress and disease. It remains debated how alternative behavioural syndromes and stress coping styles evolve and are maintained by natural selection. Here we show that individual variation in stress responsiveness is reflected in the visual appearance of two species of teleost fish; rainbow trout (Oncorhynchus mykiss) and Atlantic salmon (Salmo salar). Salmon and trout skin vary from nearly immaculate to densely spotted, with black spots formed by eumelanin-producing chromatophores. I... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532905 Mon, 15 Jun 2009 23:00:00 +0100 2532905 http://www.medworm.com/index.php?rid=2532909&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19538960%26dopt%3DAbstract Authors: Paris JJ, Franco C, Sodano R, Freidenberg B, Gordis E, Anderson DA, Forsyth JP, Wulfert E, Frye CA Sex differences in incidence and severity of some stress-related, neuropsychiatric disorders are often reported to favor men, suggesting that women may be more vulnerable to aberrant hypothalamic-pituitary-adrenal (HPA) axis responses to stress. In this review, we discuss several investigations that we, and others, have conducted assessing salivary cortisol as a measure of HPA function. We have examined basal cortisol among healthy men and women and also following acute exposure to stressors. Among healthy participants, men had higher basal cortisol levels than did women. In response to acute stressors, such as carbon dioxide or noise, respectively, cortisol levels were comparabl... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532909 Sun, 14 Jun 2009 23:00:00 +0100 2532909 http://www.medworm.com/index.php?rid=2532908&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19538961%26dopt%3DAbstract Authors: Bruce CC, Zhao C, Franklin RJ Remyelination following central nervous system (CNS) demyelination restores rapid saltatory conduction of action potentials and contributes to the maintenance of axonal integrity. This robust regenerative phenomenon stands in contrast to the limited repair capacity that is characteristic of CNS neuronal injury. However, despite its efficiency in experimental models and some clinical diseases, remyelination failure becomes an increasingly pronounced feature of the pathology of chronic multiple sclerosis (MS) lesions. Chronic demyelination predisposes axons to atrophy, an irreversible event that is a major pathological correlate of progressive functional decline. This has created a compelling case for developing therapies that promote remyelination:... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532908 Sun, 14 Jun 2009 23:00:00 +0100 2532908 http://www.medworm.com/index.php?rid=2532907&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19538962%26dopt%3DAbstract Authors: Gillies GE, McArthur S This review considers evidence which reveals considerable complexity and sex differences in the response of the nigrostriatal dopaminergic (NSDA) system to hormonal influences. This pathway degenerates in Parkinson's disease (PD) and sex hormones contribute to sex differences in PD, where men fare worse than women. Here we discuss evidence from animal studies which allows us to hypothesize that, contrary to expectations, the acclaimed neuroprotective property of physiological concentrations of estradiol arises not by promoting NSDA neuron survival, but by targeting powerful adaptive responses in the surviving neurons, which restore striatal DA functionality until over 60% of neurons are lost. Estrogen generated locally in the NSDA region appears to promo... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532907 Sun, 14 Jun 2009 23:00:00 +0100 2532907 http://www.medworm.com/index.php?rid=2532906&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19538963%26dopt%3DAbstract Authors: Melo AI, Pérez-Ledezma M, Clapp C, Arnold E, Rivera JC, Fleming AS During early life, prolactin (PRL) ingested by the pups through the milk participates in the developmental of neuroendocrine, immunological and reproductive systems. The present study tested whether a deficiency in PRL in the dam's milk during early lactation affected the offspring in terms of the maternal responsiveness in the sensitization paradigm and behavioral response to a novel environment in the offspring. Thus, lactating rats were injected (sc) on postnatal days (PND) 2-5 with bromocriptine (125mug/day), bromocriptine+ovine PRL (125mug+300 mug/day), or vehicle. As juveniles (at PND 24) or adults (PND 90-100), one female from each litter was exposed to 5 foster pups continuously for 8 days and thei... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532906 Sun, 14 Jun 2009 23:00:00 +0100 2532906 http://www.medworm.com/index.php?rid=2532911&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19524584%26dopt%3DAbstract Authors: Melcangi RC, Garcia-Segura LM Different pathologies of the central and peripheral nervous system show sex differences in their incidence, symptomatology and/or neurodegenerative outcome. These include Parkinson's disease, Alzheimer's disease, Huntington's disease, multiple sclerosis, traumatic brain injury, stroke, autism, schizophrenia, depression, anxiety disorders, eating disorders and peripheral neuropathy. These sex differences call for the search for sex-specific neuroprotective strategies. This review article and other manuscripts published in this issue of Hormones and Behavior analyze possible sex-specific therapeutic strategies based on neuroactive steroids. In particular in our introductory article, the possibility that sex differences in the levels or in the action... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532911 Wed, 10 Jun 2009 23:00:00 +0100 2532911 http://www.medworm.com/index.php?rid=2532910&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19524585%26dopt%3DAbstract Authors: Josephs RA PMID: 19524585 [PubMed - as supplied by publisher] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532910 Wed, 10 Jun 2009 23:00:00 +0100 2532910 http://www.medworm.com/index.php?rid=2532912&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19520080%26dopt%3DAbstract Authors: Parada M, Chamas L, Censi S, Coria-Avila G, Pfaus JG The present study examined the ability of clitoral stimulation (CLS) to induce conditioned place preference (CPP) and Fos protein in the brain. Ovariectomized, hormone-primed Long-Evans rats were randomly assigned to receive either distributed CLS (1 stimulation every 5 s for 1 min prior to being placed in one distinctive side of a nonbiased CPP box for 2 min, after which the cycle of stimulation and CPP exposure were repeated for 4 more cycles, totaling 60 stimulations) or continuous CLS (1 stimulation per second for 1 min with 2 min in one side of the CPP box, repeated for 4 more cycles, totaling 300 stimulations). Two days later, females were placed into the other side of the CPP box without prior stimulation. CPP was tes... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532912 Mon, 08 Jun 2009 23:00:00 +0100 2532912 http://www.medworm.com/index.php?rid=2532954&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19348808%26dopt%3DAbstract We examined the relations of 84 preschoolers' (43 boys; mean age=54 months) situational stress reactivity to their observed emotions and mothers' reports of temperament and adjustment. Salivary cortisol and salivary alpha-amylase (sAA) were collected prior to, and following, a frustrating task. Children's anger, sadness, and positive affect were measured, and mothers reported on preschoolers' dispositional emotionality, regulation, impulsivity, and problem behaviors. Forty-seven percent of children had an increase in sAA and 52% had an increase in cortisol following the challenging task. On average, sAA levels showed the predicted pattern of rise following the frustrating task, followed by return to baseline. For cortisol, there was a mean increase from pre-task to 40 min post-test. sAA re... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532954 Sun, 31 May 2009 23:00:00 +0100 2532954 http://www.medworm.com/index.php?rid=2532950&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19361511%26dopt%3DAbstract In this study, we determined that gonadectomy significantly impairs social dominance in naturalistic settings and changes reactions to social stimuli in experimental settings. Rhesus macaques were castrated (n= 6) or sham operated (n=6) at age 2.4 years, group-housed for 2 years, and ethograms were collected weekly. During adolescence the gonadally intact monkeys displayed a decrease in subordinate behaviors and an increase in dominant behaviors, which ultimately related to a rise in social status and rank in the dominance hierarchy. We measured monkey's reactions to emotional faces (fear, threat, neutral) of conspecifics of three ages (adult, peer, infant). Intact monkeys were faster to retrieve a treat in front of a threatening or infant face, while castrated monkeys did not show a diffe... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532950 Sun, 31 May 2009 23:00:00 +0100 2532950 http://www.medworm.com/index.php?rid=2532948&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19362091%26dopt%3DAbstract Authors: Mehta PH, Wuehrmann EV, Josephs RA Although theory suggests that testosterone should facilitate competitive performance, empirical evidence has been mixed. The present study tested the hypothesis that testosterone's effect on competitive performance depends on whether competition is among individuals (individual competition) or among teams (intergroup competition). Sixty participants (50% women) provided saliva samples and were randomly assigned to complete an analytical reasoning test in individual or intergroup competition. Testosterone was positively related to performance in individual competition, but testosterone was negatively related to performance in intergroup competition. There were no sex differences in performance or in the magnitude of testosterone-performance re... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532948 Sun, 31 May 2009 23:00:00 +0100 2532948 http://www.medworm.com/index.php?rid=2532946&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19362559%26dopt%3DAbstract We examined whether interpersonal closeness increases salivary progesterone. One hundred and sixty female college students (80 dyads) were randomly assigned to participate in either a closeness task with a partner versus a neutral task with a partner. Those exposed to the closeness induction had higher levels of progesterone relative to those exposed to the neutral task. Across conditions, progesterone increase one week later predicted the willingness to sacrifice for the partner. These results are discussed in terms of the links between social contact, stress, and health. PMID: 19362559 [PubMed - in process] (Source: Hormones and Behavior) Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532946 Sun, 31 May 2009 23:00:00 +0100 2532946 http://www.medworm.com/index.php?rid=2532944&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19371745%26dopt%3DAbstract Authors: Feng N, Telefont M, Kelly KJ, Orchinik M, Forster GL, Renner KJ, Lowry CA The dorsomedial hypothalamus (DMH) plays an important role in coordinating physiological and behavioral responses to stress-related stimuli. In vertebrates, DMH serotonin (5-HT) concentrations increase rapidly in response to acute stressors or corticosterone (CORT). Recent studies suggest that CORT inhibits postsynaptic clearance of 5-HT from the extracellular fluid in the DMH by blocking organic cation transporter 3 (OCT3), a polyspecific CORT-sensitive transport protein. Because OCTs are low-affinity, high-capacity transporters, we hypothesized that CORT effects on extracellular 5-HT are most pronounced in the presence of elevated 5-HT release. We predicted that local application of CORT into the DMH w... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532944 Sun, 31 May 2009 23:00:00 +0100 2532944 http://www.medworm.com/index.php?rid=2532942&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19374903%26dopt%3DAbstract Authors: Silverin B, Gwinner E, Van't Hof TJ, Schwabl I, Fusani L, Hau M, Helm B Arctic environments are challenging for circadian systems. Around the solstices, the most important zeitgeber, the change between night and day, is reduced to minor fluctuations in light intensities. However, many species including songbirds nonetheless show clear diel activity patterns. Here we examine the possible physiological basis underlying diel rhythmicity under continuous Arctic summer light. Rhythmic secretion of the hormone melatonin constitutes an important part of the songbird circadian system and its experimental suppression, e.g., by constant light, usually leads to behavioral arrhythmia. We therefore studied melatonin patterns in a free-living migratory songbird, the willow warbler (Phyllosc... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532942 Sun, 31 May 2009 23:00:00 +0100 2532942 http://www.medworm.com/index.php?rid=2532940&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19374904%26dopt%3DAbstract Authors: Ashley NT, Hays QR, Bentley GE, Wingfield JC Males of many vertebrate species are typically more prone to disease and infection than female conspecifics, and this sexual difference is partially influenced by the immunosuppressive properties of testosterone (T) in males. T-induced immunosuppression has traditionally been viewed as a pleiotropic handicap, rather than an adaptation. Recently, it has been hypothesized that suppression of sickness behavior, or the symptoms of infection, may have adaptive value if sickness interferes with the expression of T-mediated behaviors important for male reproductive success. We conduct a classic hormone replacement experiment to examine if T suppresses sickness behavior in a seasonally-breeding songbird, Gambel's white-crowned sparrow (Zono... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532940 Sun, 31 May 2009 23:00:00 +0100 2532940 http://www.medworm.com/index.php?rid=2532936&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19409390%26dopt%3DAbstract Authors: Lowry CA, Hale MW, Burke KA, Renner KJ, Moore FL The anxiety- and stress-related neuropeptide corticotropin-releasing factor (CRF) elicits behavioral changes in vertebrates including increases in behavioral arousal and locomotor activity. Intracerebroventricular injections of CRF in an amphibian, the roughskin newt (Taricha granulosa), induces rapid increases in locomotor activity in both intact and hypophysectomized animals. We hypothesized that this CRF-induced increase in locomotor activity involves a central effect of CRF on serotonergic neurons, based on known stimulatory actions of serotonin (5-hydroxytryptamine, 5-HT) on spinal motor neurons and the central pattern generator for locomotor activity in vertebrates. In Experiment 1, we found that neither intracerebroventri... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532936 Sun, 31 May 2009 23:00:00 +0100 2532936 http://www.medworm.com/index.php?rid=2532934&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19409391%26dopt%3DAbstract Authors: Jarriault D, Barrozo RB, de Carvalho Pinto CJ, Greiner B, Dufour MC, Masante-Roca I, Gramsbergen JB, Anton S, Gadenne C Male moths use sex pheromones to find their mating partners. In the moth, Agrotis ipsilon, the behavioral response and the neuron sensitivity within the primary olfactory centre, the antennal lobe (AL), to sex pheromone increase with age and juvenile hormone (JH) biosynthesis. By manipulating the JH level, we previously showed that JH controls this age-dependent neuronal plasticity, and that its effects are slow (within 2 days). We hypothesized that the hormonal effect might be indirect, and one neuromodulator candidate, which might serve as a mediator, is octopamine (OA). Here, we studied the effects of OA and an OA receptor antagonist, mianserin, on behavio... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532934 Sun, 31 May 2009 23:00:00 +0100 2532934 http://www.medworm.com/index.php?rid=2532913&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19460379%26dopt%3DAbstract Authors: Keen-Rhinehart E, Desai M, Ross MG The incidence of juvenile obesity is increasing at an alarming rate. In adults, central insulin administration decreases hypothalamic orexigenic neuropeptides, food intake and body weight more effectively in males than females. Mechanisms regulating energy balance in juvenile animals are inherently different from those in adults due to differences in growth rates and hormonal milieu. Therefore, we sought to determine if central insulin treatment in juvenile rats (4 wk) would have similar sex-dependent effects on food intake as those reported in adult rats. Twenty-four hour food intake was measured following icv saline or insulin (0.01 or 0.1 U) prior to the onset of dark phase of the light cycle. An additional set of animals was used to asses... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532913 Mon, 18 May 2009 23:00:00 +0100 2532913 http://www.medworm.com/index.php?rid=2532916&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19450598%26dopt%3DAbstract Authors: Barbosa-Vargas E, Pfaus JG, Woodside B Lactation is associated with suppression of reproductive function, the duration of which depends on the number of young suckled and food availability. Although previous studies have documented increasing responsivity to the positive feedback effects of estrogen on luteinizing hormone (LH) secretion with time postpartum, changes in the ability of estrogen to stimulate sexual behavior across these time points and the influence of food restriction on response to estrogen have not been investigated. Thus, we compared the ability of exogenous estrogen administration to stimulate proceptive and receptive behavior in ad libitum fed and food restricted rats on Days 15 and 20 postpartum. Because the ability of estrogen to induce sexual behavior de... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532916 Sun, 17 May 2009 23:00:00 +0100 2532916 http://www.medworm.com/index.php?rid=2532915&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19450599%26dopt%3DAbstract Authors: Park JH, Bonthuis P, Ding A, Rais S, Rissman EF Male reproductive behavior is highly dependent upon gonadal steroids. However, between individuals and across species, the role of gonadal steroids in male reproductive behavior is highly variable. In male B6D2F1 hybrid mice, a large proportion (about 30%) of animals demonstrate the persistence of the ejaculatory reflex long after castration. This provides a model to investigate the basis of gonadal steroid-independent male sexual behavior. Here we assessed whether non-gonadal steroids promote mating behavior in castrated mice. Castrated B6D2F1 hybrids that persisted in copulating (persistent copulators) were treated with the androgen receptor blocker, flutamide, and the aromatase enzyme inhibitor, letrozole, for 8 weeks. Other a... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532915 Sun, 17 May 2009 23:00:00 +0100 2532915 http://www.medworm.com/index.php?rid=2532914&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19450600%26dopt%3DAbstract Authors: Allee SJ, Markham MR, Stoddard PK Sex steroids were initially defined by their actions shaping sexually dimorphic behavioral patterns. More recently scientists have begun exploring the role of steroids in determining sex differences in behavioral plasticity. We investigated the role of androgens in potentiating circadian, pharmacological, and socially-induced plasticity in the amplitude and duration of electric organ discharges (EODs) of female gymnotiform fish. We first challenged female fish with injections of serotonin (5-HT) and adrenocorticotropic hormone (ACTH), and with social encounters with female and male conspecifics to characterize females' pre-implant responses to each treatment. Each individual was then implanted with a pellet containing dihydrotestosterone (DHT)... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532914 Sun, 17 May 2009 23:00:00 +0100 2532914 http://www.medworm.com/index.php?rid=2532917&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19447109%26dopt%3DAbstract Authors: Brinks V, Berger S, Gass P, de Kloet ER, Oitzl MS The stress hormone corticosterone acts via two receptor types in the brain: the mineralocorticoid (MR) and the glucocorticoid receptor (GR). Both receptors are involved in processing of stressful events. A disbalance of MR:GR functions is thought to promote stress-related disorders. Here we studied the effect of stress on emotional and cognitive behaviors in mice with forebrain-specific inactivation of the MR gene (MR(CaMKCre), 4 months old; and control littermates). MR(CaMKCre) mice responded to prior stress (5 min of restraint) with higher arousal and less locomotor activity in an exploration task. A fear conditioning paradigm allowed assessing in one experimental procedure both context- and cue-related fear. During condition... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532917 Thu, 14 May 2009 23:00:00 +0100 2532917 http://www.medworm.com/index.php?rid=2532918&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19446557%26dopt%3DAbstract Authors: Neff BD, Knapp R Like many teleost fishes, bluegill (Lepomis macrochirus) are characterized by sole male parental care of offspring. In addition, bluegill parental males experience cuckoldry by specialized parasitic male morphs. This cuckoldry has previously been shown to influence the expression of parental care behavior. To better understand some of the proximate mechanisms mediating parental behavior, we examined the relationships between circulating steroid hormones, paternity, and parental behavior during the egg and fry stages of care in parentals that spawned during the first third of the breeding season. During the egg stage of care, we found that males with higher paternity had lower levels of testosterone, but there was no relationship between paternity and either 11... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532918 Wed, 13 May 2009 23:00:00 +0100 2532918 http://www.medworm.com/index.php?rid=2532929&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19433091%26dopt%3DAbstract Authors: de Jong TR, Chauke M, Harris BN, Saltzman W In a minority of mammalian species, including humans, fathers play a significant role in infant care. Compared to maternal behavior, the neural and hormonal bases of paternal care are poorly understood. We analyzed behavioral, neuronal and neuropeptide responses towards unfamiliar pups in biparental California mice, comparing males housed with another male ("virgin males") or with a female before ("paired males") or after ("new fathers") the birth of their first litter. New fathers approached pups more rapidly and spent more time engaging in paternal behavior than virgin males. In each cage housing two virgin males, one was spontaneously paternal and one was not. New fathers and paired males spent more time sniffing and touching a wi... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532929 Fri, 08 May 2009 23:00:00 +0100 2532929 http://www.medworm.com/index.php?rid=2532931&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19422828%26dopt%3DAbstract Authors: Pesaresi M, Maschi O, Giatti S, Garcia-Segura LM, Caruso D, Melcangi RC Neuropathy and encephalopathy represent important complications of diabetes. Recent observations obtained in experimental models have suggested that, in male rats, neuroactive steroids are protective agents and that their levels in peripheral (PNS) and central (CNS) nervous system are strongly affected by the disease. It is interesting to highlight that incidence, progression and severity of diabetic neuropathy and diabetic encephalopathy are different in the two sexes. Consequently, it is important to determine the changes in neuroactive steroid levels in the PNS and the CNS of both males and females. To this aim, we have evaluated the levels of neuroactive steroids such as, pregnenolone, progesterone and... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532931 Mon, 04 May 2009 23:00:00 +0100 2532931 http://www.medworm.com/index.php?rid=2532930&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19426733%26dopt%3DAbstract Authors: Fuxjager MJ, Mast G, Becker EA, Marler CA Winning aggressive contests can both enhance future winning ability and change post-encounter hormones; however, it remains unclear if the context of a fight also influences such winner effects and hormone changes. We investigated this issue by using California mice (Peromyscus californicus) to test if the effect of residency status is necessary to improve future winning ability and alter post-encounter hormones. Male mice were subjected to an aggressive contest and their blood was collected 45 min after the fight. Upon contest initiation, focal mice had a 'home advantage' and three prior winning experiences, only one of these factors, or neither factor. Only individuals with a 'home advantage' and prior winning experience showed a ful... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532930 Mon, 04 May 2009 23:00:00 +0100 2532930 http://www.medworm.com/index.php?rid=2532938&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19406124%26dopt%3DAbstract Authors: Schmidt B, Jacobson TK, Markus E Estrogen has been demonstrated to enhance the use of hippocampal-based place learning while reducing the use of striatal-based motor-response strategy (Korol, D.L., Malin, E.L., Borden, K.A., Busby, R.A., & Couper-Leo, J. (2004). Shifts in preferred learning strategy across the estrous cycle in female rats. Horm. Behav. 45, 330-338). Previous research has focused on task acquisition and the switch from a place to motor-response navigation with training. The current paradigm allowed an examination of the interplay between these two systems by having well-trained animals switch strategies "on demand." Female and male Sprague-Dawley rats were taught a motor-response task on a plus maze. The rats were then introduced to a place task and taught ... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532938 Sat, 02 May 2009 23:00:00 +0100 2532938 http://www.medworm.com/index.php?rid=2532932&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19409392%26dopt%3DAbstract Authors: van Anders SM, Dunn EJ Past findings suggest links between orgasms and testosterone (T), as well as sexuality and estradiol (E), and we examined hormone-orgasm links in this study via two hypotheses (below). Participants were 86 women and 91 men who provided a saliva sample and completed a demographics questionnaire, the Orgasm Checklist (Mah and Binik, 2002), the Hurlbert (1991) Index of Sexual Assertiveness, and the Sexual Desire Inventory (Spector and Fremeth, 1996). Results supported the first hypothesis of correlations between T and positive orgasm experience in women, specifically with the relaxation, soothing, and peaceful items in both partnered and solitary orgasm contexts. Results also indicated correlations between E and flooding and spreading items in a solitary or... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532932 Sat, 02 May 2009 23:00:00 +0100 2532932 http://www.medworm.com/index.php?rid=2532928&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19446072%26dopt%3DAbstract Authors: Wallen K The 1959 publication of "Organizing action of prenatally administered testosterone propionate on the tissues mediating mating behavior in the female guinea pig" by Charles H. Phoenix, Robert W. Goy, Arnold A. Gerall, and William C. Young transformed how sex differences in mating behavior were thought to develop. Previous work provided extensive evidence that steroid hormones activated patterns of male and female sexual behavior, but only activated the behavioral patterns typical of a given sex. The 1959 paper explained this phenomenon by arguing that androgens, or their metabolites, acting at specific time(s) during development sexually dimorphically organized the tissues mediating mating behavior, which were activated by appropriate hormonal stimulation in adulthood.... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532928 Thu, 30 Apr 2009 23:00:00 +0100 2532928 http://www.medworm.com/index.php?rid=2532927&cid=s_35621_15_f&fid=35621&url=http%3A%2F%2Fwww.ncbi.nlm.nih.gov%2Fentrez%2Fquery.fcgi%3Ftmpl%3DNoSidebarfile%26db%3DPubMed%26cmd%3DRetrieve%26list_uids%3D19446073%26dopt%3DAbstract Authors: Arnold AP The 1959 publication of the paper by Phoenix et al. was a major turning point in the study of sexual differentiation of the brain. That study showed that sex differences in behavior, and by extension in the brain, were permanently sexually differentiated by testosterone, a testicular secretion, during an early critical period of development. The study placed the brain together in a class with other major sexually dimorphic tissues (external genitalia and genital tracts), and proposed an integrated hormonal theory of sexual differentiation for all of these non-gonadal tissues. Since 1959, the organizational-activational theory has been amended but survives as a central concept that explains many sex differences in phenotype, in diverse tissues and at all levels of ana... Hormones and Behavior journals http://www.medworm.com/rss/comments.php?id=2532927 Thu, 30 Apr 2009 23:00:00 +0100 2532927