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Dopamine D3 receptor selective ligands with varying intrinsic efficacies at adenylyl cyclase inhibition and mitogenic signaling pathwaysEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A panel of structurally related substituted 4-phenylpiperazines with nanomolar affinity and selectivity at D3 dopamine receptors has been synthesized. Compounds in which a heterocyclic (2-phenyl pyridyl, 3-phenyl pyridyl, benzothiophene, or benzofuran) moiety is adjacent to the amide was varied and/or a double bond (trans-butenyl) replaced the four-carbon aliphatic chain linking the arylamide with the 4-phenylpiperazine moiety were compared for (a) affinity at human D2 and D3 dopamine receptors, (b) intrinsic efficacy using an adenylyl cyclase inhibition assay, and (c) intrinsic efficacy using a mitogenic assay. All 16 com...
Source: Synapse - November 18, 2009 Category: Neurology Authors: Michelle Taylor, Peter Grundt, Suzy A. Griffin, Amy Hauck Newman, Robert R. Luedtke Source Type: journals

The pattern of neuronal loss and survival may reflect differential expression of proteasome activators in Parkinson's diseaseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we employed an immunocytochemical approach to determine if the differential expression of key UPS components in various brain regions and cells might underlie the pattern of neuronal degeneration and survival seen in PD. We showed that the ubiquitin activating enzyme (E1), ubiquitin conjugating enzyme (E2), and 26/20S proteasome [alpha]- and [beta]-subunits, are abundantly expressed in the substantia nigra pars compacta (SNc) and in cultured dopaminergic neurons. Although the proteasome activator PA700 is expressed in the medial SNc, levels are low in the lateral region, and expression of the other proteasom...
Source: Synapse - November 18, 2009 Category: Neurology Authors: Kevin St.P. Mcnaught, Ruth Jnobaptiste, Tehone Jackson, Toni-Ann Jengelley Source Type: journals

Chronic fluoxetine treatment has a larger effect on the density of a serotonin transporter in the Flinders Sensitive Line (FSL) rat model of depression than in normal ratsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The objective of the present investigation was to assess the influence of chronic fluoxetine treatment on SERT density (Bmax; fmol/mg) in the FSL rat model of depression, relative to that in the FRL rats and SPD rats. FSL, FRL and SPD rats were randomly assigned into groups receiving the vehicle or 10 mg/kg of fluoxetine i.p. for 14 days. Binding was assessed by incubating the brain sections in a buffer containing 20 pM of [125I]-RTI-55 [[125I](-)-2[beta]-carbomethoxy-3[beta]-(4-iodophenyl)tropane and 200 nM of GBR12935 [1-(2-(diphenylmethoxy)ethyl)-4-(3-phenylpropyl)piperazine]. The fluoxetine treatment reduced Bmax in al...
Source: Synapse - November 18, 2009 Category: Neurology Authors: Tomislav Kova[ccaron]evi[cacute], Ivan Skelin, Mirko Diksic Source Type: journals

Ethanol and PTZ effects on siRNA-mediated GABAB1 receptor: Down regulation of intracellular signaling pathway in prenatal rat cortical and hippocampal neuronsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
GABAB receptors (R) are widely expressed and distributed in the nervous system, and have been implicated in variety of neurodegenerative and pathophysiological disorders. However, the exact molecular mechanism regarding responsibility of GABAB1R in downstream signaling pathway is not well understood. The present study was undertaken to explore the downstream signaling and role of GABAB1R upon acute ethanol and pentylenetetrazol (PTZ) exposure for (20 min) in cortical and hippocampal neuronal cell cultures by using GABAB1R RNA interference (i) (30 nM, 48 h) at gestational days 17.5. The results showed that GABAB1R and prote...
Source: Synapse - October 27, 2009 Category: Neurology Authors: M.I. Naseer, H.Y. Lee, N. Ullah, I. Ullah, M.S. Park, S.H. Kim, M.O. Kim Source Type: journals

Alterations in 5-HT2A receptor binding in various brain regions among 6-hydroxydopamine-induced Parkinsonian ratsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study aims to investigate regional changes in 5-hydroxytryptamine (5-HT) 2A receptors in the rat brain 3 weeks after unilateral medial forebrain bundle lesion by 6-hydroxydopamine (6-OHDA). 5-HT 2A receptor distributions and alterations in the postmortem rat brain were detected by [3H]ketanserin-binding autoradiography. In the 6-OHDA-induced Parkinson's rat model, nigrostriatal dopaminergic neuron loss significantly mediated the decreased [3H]ketanserin binding, predominantly in the agranular insular cortex (17.3%, P = 0.03), cingulate cortex (18.2%, P < 0.001), prefrontal cortex (8%, P = 0.043), primary somatosensory...
Source: Synapse - October 26, 2009 Category: Neurology Authors: Yun Li, Xu-Feng Huang, Chao Deng, Barbara Meyer, Aimin Wu, Yinghua Yu, Weihai Ying, Guo-Yuan Yang, Midori A Yenari, Qing Wang Source Type: journals

Muscarinic receptor blockade in the ventral tegmental area attenuates cocaine enhancement of laterodorsal tegmentum stimulation-evoked accumbens dopamine efflux in the mouseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The reinforcing properties of cocaine have been related to increased extracellular concentrations of dopamine in the nucleus accumbens (NAc). M5 muscarinic acetylcholine receptors (mAChRs) on dopamine cells in the ventral tegmental area (VTA) facilitate mesoaccumbens dopamine transmission and are critically involved in mediating natural and drug reinforcement. We investigated the effects of pharmacological blockade of mAChRs in the VTA on cocaine's ability to enhance electrically evoked NAc dopamine efflux. Using fixed potential amperometry together with carbon fiber recording microelectrodes positioned in the NAc core, we...
Source: Synapse - October 26, 2009 Category: Neurology Authors: Deranda B. Lester, Anthony D. Miller, Charles D. Blaha Source Type: journals

In vivo evaluation of N-[18F]fluoroethylpiperidin-4ylmethyl acetate in rats compared with MP4A as a probe for measuring cerebral acetylcholinesterase activityEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
[11C]MP4A is an established radioprobe for quantification of cerebral acetylcholinesterase (AChE) activity by positron emission tomography (PET) based on the kinetics of AChE-mediated metabolism and metabolite trapping. It has been used to assess the deficiency in cholinergic innervation in the brain of patients with dementia. Because 18F has a longer half-life than 11C, 18F-labeled derivatives of [11C]MP4A allow delivery of the probe to other PET centers, making AChE measurement more widely applicable. Previously, N-[18F]fluoroethylpiperidin-4ylmethyl acetate ([18F]FEP-4MA) showed that the 18F-labeled analog of MP4A posse...
Source: Synapse - October 26, 2009 Category: Neurology Authors: Tatsuya Kikuchi, Toshimitsu Okamura, Ming-Rong Zhang, Kiyoshi Fukushi, Toshiaki Irie Source Type: journals

Positron emission tomography kinetic modeling algorithms for small animal dopaminergic system imagingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Small animal positron emission tomography (PET) imaging allows in vivo quantification of lesion- or treatment-induced neurochemical changes in animal models of disease. Important for quantification are the kinetic modeling methods used to determine biologically-relevant parameters of tracer-tissue interaction. In this work, we evaluate modeling algorithms for the dopaminergic tracers 11C-dihydrotetrabenazine (DTBZ), 11C-methylphenidate (MP), and 11C-raclopride (RAC), used to image the dopaminergic system in the unilateral 6-hydroxydopamine lesioned rat model of Parkinson's disease. For the presynaptic tracers, PET measures...
Source: Synapse - October 26, 2009 Category: Neurology Authors: Geoffrey J. Topping, Katie Dinelle, Rick Kornelsen, Siobhan McCormick, James E. Holden, Vesna Sossi Source Type: journals

Early exposure to haloperidol or olanzapine induces long-term alterations of dendritic formEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Exposure of the developing brain to a wide variety of drugs of abuse (e.g., stimulants, opioids, ethanol, etc.) can induce life-long changes in behavior and neural circuitry. However, the long-term effects of exposure to therapeutic, psychotropic drugs have only recently begun to be appreciated. Antipsychotic drugs are little studied in this regard. Here, we quantitatively analyzed dendritic architecture in adult mice treated with paradigmatic typical- (haloperidol) or atypical (olanzapine) antipsychotic drugs at developmental stages corresponding to fetal or fetal plus early childhood stages in humans. In layer 3 pyramida...
Source: Synapse - October 26, 2009 Category: Neurology Authors: Douglas O. Frost, Stephanie Cerceo Page, Cathy Carroll, Bryan Kolb Source Type: journals

Synaptic recruitment of AMPA glutamate receptor subunits in levodopa-induced dyskinesia in the MPTP-lesioned nonhuman primateEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
No abstract. (Source: Synapse)
Source: Synapse - October 21, 2009 Category: Neurology Authors: Monty A. Silverdale, Christopher Kobylecki, Penelope J. Hallett, Qin Li, Anthone W. Dunah, Paula Ravenscroft, Erwan Bezard, Jonathan M. Brotchie Source Type: journals

Effects of cAMP-dependent protein kinase activator and inhibitor on in vivo rolipram binding to phosphodiesterase 4 in conscious ratsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Rolipram is a selective inhibitor of phosphodiesterase-4 (PDE4), and positron emission tomography (PET) using [11C]rolipram can monitor the in vivo activity of this enzyme that is part of the cAMP second messenger cascade. cAMP-dependent protein kinase (PKA) phosphorylates PDE4 and increases both enzyme activity and affinity for rolipram. In the present PET study, we examined effects of PKA modulators in conscious rats on the binding of [11C](R)-rolipram in comparison to the much less active enantiomer [11C](S)-rolipram. Unilateral injection of a PKA activator (dibutyryl-cAMP) and a PKA inhibitor (Rp-adenosine-3[prime],5[p...
Source: Synapse - October 21, 2009 Category: Neurology Authors: Tetsuji Itoh, Kohji Abe, Jinsoo Hong, Osamu Inoue, Victor W. Pike, Robert B. Innis, Masahiro Fujita Source Type: journals

Altered response to antidepressant treatment in FoxG1 heterozygous knockout miceEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Evidence from a variety of sources suggests that structural alterations in the brain, including neurogenesis, may play a role in both the pathogenesis of mood disorders and the mechanism of action of antidepressants. Previous studies have implicated both the transforming growth factor-beta (TGF-[beta]), and the phosphatidyl inositol-3 kinase (PI3K)-Akt pathways in the neurogenesis-promoting and behavioral properties of antidepressants. Forkhead box protein G1 (FoxG1) is a major regulator of both of these pathways, and FoxG1 heterozygous null mice (FoxG1+/-) have previously been reported to have deficits in adult hippocampa...
Source: Synapse - October 21, 2009 Category: Neurology Authors: Rebecca Kinsler, Mary Morgan Taylor, Natasha M. Flores, Janine J. Leffert, Robert D. Beech Source Type: journals

N-ethyl lidocaine (QX-314) protects striatal neurons against ischemia: An in vitro electrophysiological studyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we have investigated the neuroprotective actions of the membrane impermeable, lidocaine analog, N-ethyl lidocaine (QX-314) in the striatum. The effects of this drug were compared with those caused by the strictly-related-compound and sodium channel blocker lidocaine. To address this issue, electrophysiological recordings were performed in striatal slices, in control condition (normoxia) and during combined oxygen and glucose deprivation (in vitro ischemia). Either QX-314 or lidocaine induced, to some extent, a protection of the permanent electrophysiological alteration (field potential loss) caused by a peri...
Source: Synapse - October 21, 2009 Category: Neurology Authors: Marta Armogida, Michela Giustizieri, Cristina Zona, Silvia Piccirilli, Robert Nisticò, Nicola B. Mercuri Source Type: journals

Effects of 660-nm gallium-aluminum-arsenide low-energy laser on nerve regeneration after acellular nerve allograft in ratsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Conclusions: These findings demonstrate that 660-nm GaAlAs LEL therapy upregulates CGRP protein and mRNA expression of the L4 spinal cord at the injury site and increases the rate of regeneration and target reinnervation after acellular nerve allograft repair of the sciatic nerve gap in rats. Low-energy laser irradiation may be a useful, noninvasive adjunct for promoting nerve regeneration in surgically induced defects repaired with ARSN. Synapse 64:152-160, 2010. © 2009 Wiley-Liss, Inc. (Source: Synapse)
Source: Synapse - October 21, 2009 Category: Neurology Authors: Li-Xin Zhang, Xiao-Jie Tong, Xiu-Hua Yuan, Xiao-Hong Sun, Hua Jia Source Type: journals

Dopamine transporter PET in normal aging: Dopamine transporter decline and its possible role in preservation of motor functionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Conclusions: Our findings confirm prior observations of age-related DAT decline and suggest that this phenomenon is independent of changes in VMAT2. After the fifth decade of life, this reduction in DAT binding is associated with a motor performance comparable to mid-adult life. These findings imply that biochemical processes associated with healthy aging may offset the naturaldecline in motor function observed in the elderly. Synapse 64:146-151, 2010. © 2009 Wiley-Liss, Inc. (Source: Synapse)
Source: Synapse - October 21, 2009 Category: Neurology Authors: André R. Troiano, Michael Schulzer, Raul de La Fuente-Fernandez, Edwin Mak, Jess Mckenzie, Vesna Sossi, Siobhan Mccormick, Thomas J. Ruth, A. Jon Stoessl Source Type: journals

Effect of the environment on the dendritic morphology of the rat auditory cortexEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The present study aimed to identify morphological correlates of environment-induced changes at excitatory synapses of the primary auditory cortex (A1). We used the Golgi-Cox stain technique to compare pyramidal cells dendritic properties of Sprague-Dawley rats exposed to different environmental manipulations. Sholl analysis, dendritic length measures, and spine density counts were used to monitor the effects of sensory deafness and an auditory version of environmental enrichment (EE). We found that deafness decreased apical dendritic length leaving basal dendritic length unchanged, whereas EE selectively increased basal de...
Source: Synapse - September 21, 2009 Category: Neurology Authors: Mitali Bose, Pablo Muñoz-llancao, Swagata Roychowdhury, Justin A. Nichols, Vikram Jakkamsetti, Benjamin Porter, Rajasekhar Byrapureddy, Humberto Salgado, Michael P. Kilgard, Francisco Aboitiz, Alexies Dagnino-Subiabre, Marco Atzori Source Type: journals

Nicotine withdrawal produces a decrease in extracellular levels of dopamine in the nucleus accumbens that is lower in adolescent versus adult male ratsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study compared dopamine levels in the NAcc of male adolescent and adult rats experiencing nicotine withdrawal. Animals were prepared with subcutaneous pumps that delivered an equivalent nicotine dose in these age groups. Following 13 days of nicotine exposure, rats were implanted unilaterally with microdialysis probes into the NAcc and ipsilateral ventral tegmental area (VTA). The next day, dialysate levels were collected following systemic administration of the nicotinic-receptor antagonist mecamylamine to precipitate withdrawal. Mecamylamine produced an average % decrease in NAcc dopamine that was lower in adolescen...
Source: Synapse - September 20, 2009 Category: Neurology Authors: Luis A. Natividad, Hugo A. Tejeda, Oscar V. Torres, Laura E. O'dell Source Type: journals

Postnatal binge-like alcohol exposure decreases dendritic complexity while increasing the density of mature spines in mPFC Layer II/III pyramidal neuronsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, three groups of rat pups were used: intubated with alcohol (5.25 g/kg/day; AE), sham intubated (SI), or suckle controls (SC) on PD 4-9. On PD 26-30 rats were anesthetized, perfused with saline and brains were processed for Golgi-Cox staining. Basilar dendritic complexity, spine density, and spine phenotypes were evaluated for Layer II/III neurons in the medial PFC. Results indicate that AE rats have an altered basilar dendritic complexity due to a significant decrease in both length and number of intersections in proximity to the neuronal soma. Furthermore, spine density patterns of basilar dendrites remain ...
Source: Synapse - September 20, 2009 Category: Neurology Authors: Gillian F. Hamilton, Lee T. Whitcher, Anna Y. Klintsova Source Type: journals

The selective [alpha]1 adrenoceptor antagonist HEAT reduces L-DOPA-induced dyskinesia in a rat model of Parkinson's diseaseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In conclusion, these results demonstrated for the first time that a [alpha]1 adrenoceptor antagonist reduced L-DOPA-induced dyskinesia in a rat model. Further studies assessing the risk benefit in comparison to existing therapies are needed before considering [alpha]1 adrenoceptor antagonists as a target for the development of new antidyskinetic compounds. Synapse 64:117-126, 2010. © 2009 Wiley-Liss, Inc. (Source: Synapse)
Source: Synapse - September 20, 2009 Category: Neurology Authors: Kerstin Buck, Boris Ferger Source Type: journals

SSRI antidepressants do not confound single photon emission computed tomography (SPECT) imaging studies using the [alpha]4[beta]2 nicotinic acetylcholine receptor [123I]5-I-A85380 ligand: In vivo and in vitro evidenceEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Conclusion: SPECT imaging studies using [123I]5-I-A85380 to measure [alpha]4[beta]2 nAChR availability in depressed patients are unlikely to be confounded to a major degree by concurrent antidepressant medication. Synapse 64:111-116, 2010. © 2009 Wiley-Liss, Inc. (Source: Synapse)
Source: Synapse - September 20, 2009 Category: Neurology Authors: Jonathan Cavanagh, James Patterson, Sally Pimlott, David Wyper, Deborah Dewar Source Type: journals

A nonsynonymous polymorphism in cannabinoid CB2 receptor gene is associated with eating disorders in humans and food intake is modified in mice by its ligandsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Marijuana use activates cannabinoid receptors (CB-Rs) producing several behavioral effects related to addiction, mood, and appetite. We investigated the association between CNR2 gene, which encodes cannabinoid CB2 receptor (CB2-R) and eating disorders in 204 subjects with eating disorders and 1876 healthy volunteers in Japanese population. The effect of treatment with CB2-R ligands on mouse food consumption was also determined. The CB2-R ligands used suppressed food intake in a time- and strain-dependent manner when food was available ad libitum and during the 12-h fast except, AM 630 - the CB2-R antagonist that stimulated...
Source: Synapse - September 17, 2009 Category: Neurology Authors: H. Ishiguro, O. Carpio, Y. Horiuchi, A. Shu, S. Higuchi, N. Schanz, R. Benno, T. Arinami, E.S. Onaivi Source Type: journals

[Gly14]-humanin rescues long-term potentiation from amyloid [beta] protein-induced impairment in the rat hippocampal CA1 region in vivoEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The novel neuroprotective action of Humanin (HN), especially its derivative [Gly14]-humanin (HNG), against Alzheimer's disease (AD)-related insults has been reported. However, it is still short of electrophysiological evidence for the protection of HN on synaptic plasticity, and the molecular mechanisms that underlie the neuroprotective function of HN remain largely unknown. The present study examined the effects of intracerebroventricular (i.c.v.) injection of HNG on amyloid [beta] (A[beta]), a main constituent of senile plaques in the AD brain, induced suppression of long-term potentiation (LTP) in the rat hippocampal CA...
Source: Synapse - September 17, 2009 Category: Neurology Authors: Fen Guo, Wei Jing, Cun-Gen Ma, Mei-Na Wu, Jun-Fang Zhang, Xin-Yi Li, Jin-Shun Qi Source Type: journals

MDMA-evoked changes in the binding of dopamine D2 receptor ligands in striatum of rats with unilateral serotonin depletionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We earlier reported an anomalous 50% decrease in [11C]N-methylspiperone ([11C]NMSP) binding to dopamine D2-like receptors in living pig striatum after challenge with 3,4-methylenedioxymethamphetamine (MDMA, "Ecstasy"), suggesting either (1) a species peculiarity in the vulnerability of butyrophenone binding to competition from dopamine or (2) a novel consequence of synergistic actions of serotonin and dopamine at dopamine receptors. To distinguish these possibilities, we used microPET to test the vulnerability of [11C]NMSP binding in striatum of rats with unilateral telencephalic serotonin lesions, later verified by [125I]...
Source: Synapse - September 17, 2009 Category: Neurology Authors: Søren Dinesen Østergaard, Aage Kristian Olsen Alstrup, Jan Bert Gramsbergen, Luciano Minuzzi, Kasper Pedersen, Svend Borup Jensen, Doris Doudet, Paul Cumming Source Type: journals

[11C]SL25.1188, a new reversible radioligand to study the monoamine oxidase type B with PET: Preclinical characterisation in nonhuman primateEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
[11C]SL-25.1188 [(S)-5-methoxymethyl-3-[6-(4,4,4-trifluorobutoxy)-benzo[d]isoxazol-3-yl]-oxazolidin-2-one], an oxazolidinone derivative, was characterized in baboons as a radioligand for the in vivo visualization of MAO-B using positron emission tomography (PET). After i.v. injection, [11C]SL25.1188 presented a rapid phase of distribution in blood (about 5 min), followed by a T1/2 elimination of 85 ± 14 min. Plasma metabolism analysis showed that [11C]SL25.1188 is stable in vivo at least for 30 min. Brain uptake was rapid with the highest one observed in the striatum and thalamus, and the lowest in the pons. Calculated di...
Source: Synapse - September 1, 2009 Category: Neurology Authors: Wadad Saba, Héric Valette, Marie-Anne Peyronneau, Yann Bramoullé, Christine Coulon, Olivier Curet, Pascal George, Frédéric Dollé, Michel Bottlaender Source Type: journals

Identification of gene transcripts expressed by postsynaptic neurons during synapse formation encoding cell surface proteins with presumptive synaptogenic activityEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Synapse formation is a well-programmed developmental process involving a variety of cell-cell interactions carried out by distinct groups of molecules. Various molecules that contribute to the assembly of synaptic contacts have been characterized; however, the repertoire of identified proteins expressed by postsynaptic neurons capable of inducing presynaptic differentiation is quite limited. To identify gene transcripts encoding cell surface proteins expressed by postsynaptic cells with molecular features suggestive of synaptogenic activity, this study carried out a genome-wide expression analysis in the chick ciliary gang...
Source: Synapse - September 1, 2009 Category: Neurology Authors: Juan L. Brusés Source Type: journals

Changes in hippocampal arc protein expression and synaptic plasticity by the presentation of contextual cues linked to drug experienceEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In this study, we investigated if the environmental context associated with withdrawal experience was able to evoke the same behavioral alteration observed after chronic benzodiazepine administration. Furthermore, we studied the hippocampal synaptic plasticity and anatomical expression of Arc protein during withdrawal and the re-exposure to the context associated with anxiety expression (characteristic sign of benzodiazepines withdrawal). It was demonstrated that re-exposure evoked on days 15 and 25 after the first exposure the same behavior. An increased hippocampal synaptic plasticity, expressed as a lower threshold to i...
Source: Synapse - September 1, 2009 Category: Neurology Authors: María Carolina Monti, Romina Soledad Almirón, Elena A. Bignante, Oscar Ángel Ramírez Source Type: journals

PET imaging of the effects of age and cocaine on the norepinephrine transporter in the human brain using (S,S)-[11C]O-methylreboxetine and HRRTEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Conclusion: Our results suggest that (a) brain NET concentration declines with age in HC, and (b) there is a significant upregulation of NET in thalamus and dorsomedial thalamic nucleus in COC as compared to HC. Our results also suggest that the use of [11C]MRB and HRRT provides an effective strategy for studying alterations of the NET system in humans. Synapse 64:30-38, 2010. © 2009 Wiley-Liss, Inc. (Source: Synapse)
Source: Synapse - September 1, 2009 Category: Neurology Authors: Yu-Shin Ding, Tarun Singhal, Beata Planeta-Wilson, Jean-Dominique Gallezot, Nabeel Nabulsi, David Labaree, Jim Ropchan, Shannan Henry, Wendol Williams, Richard E. Carson, Alexander Neumeister, Robert T. Malison Source Type: journals

Orbitofrontal and insular cortex: Neural responses to cocaine-associated cues and cocaine self-administrationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Based on neuro-imaging studies in cocaine-addicted humans, it is hypothesized that increases in neural activity within several regions of the prefrontal cortex contribute to cue-induced cocaine seeking and cocaine-induced compulsive drug self-administration. However, electrophysiological tests of these hypotheses are lacking. In the present study, animals were trained to self-administer cocaine (0.75 mg/kg) for 14 days. On the 14th day, we conducted electrophysiological recordings of lateral orbitofrontal (LO) and ventral anterior insula (AIV) neurons. A subset of the combined population of recorded neurons showed a change...
Source: Synapse - September 1, 2009 Category: Neurology Authors: Karine Guillem, Alexxai V. Kravitz, David E. Moorman, Laura L. Peoples Source Type: journals

Two opposite effects of [Delta]9-tetrahydrocannabinol on subthalamic nucleus neuron activity: Involvement of GABAergic and glutamatergic neurotransmissionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Activation of CB1 cannabinoid receptors in the basal ganglia interferes with movement regulation. The aim of this study was to characterize the effect of [Delta]9-tetrahydrocannabinol ([Delta]9-THC) on neurons in the subthalamic nucleus (STN) and to elucidate the mechanisms involved in this effect using single-unit extracellular recordings in anesthetized rats. Administration of [Delta]9-THC (0.25-2 mg/kg, i.v.) stimulated (by 107% ± 32%) neurons mainly recorded in the ventromedial portion of the caudal STN, whereas it inhibited (by 65% ± 4%) neurons recorded in the dorsolateral portion of the rostral STN. The CB1 recept...
Source: Synapse - August 31, 2009 Category: Neurology Authors: Teresa Morera-Herreras, Jose Angel Ruiz-Ortega, Luisa Ugedo Source Type: journals

Synaptic vesicles in motor synapses change size and distribution during the dayEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The morphology of Drosophila motor terminals changes along the day with a circadian rhythm controlled by the biological clock. Here, we used electron microscopy to investigate the size, number, and distribution of synaptic vesicles, at intervals of 6 h during 2 consecutive days, under light-dark (LD) or the first 2 days in constant darkness (DD). We found changes in the size and distribution of vesicles located either at the active zone or in the reserve pool, indicating a circadian rhythm of synapse reorganization. Vesicles at the active zone were generally smaller than those in the reserve pool in LD and DD conditions. T...
Source: Synapse - August 31, 2009 Category: Neurology Authors: Santiago Ruiz, Maria Jose Ferreiro, Gabriela Casanova, Alvaro Olivera, Rafael Cantera Source Type: journals

Prenatal morphine exposure alters the layer II/III pyramidal neurons morphology in lateral secondary visual cortex of juvenile ratsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Altered cortical neuronal morphology and juvenle behavior manifestation by prenatal morphine exposure were well documented. However, this developmental morphine exposure affect the lateral secondary visual area (V2L), which may be critically involved in the multisensory of auditory and visual stimulus, remained poorly understood. To clarify the neuronal architecture changes possibly occurring in the V2L, Golgi-Cox staining was used in this study to count dendritic length and the spine density of the layer II/III pyramidal neurons in the V2L of the juvenile rats (postnatal day 25, PND25) prenatally exposed to morphine (gest...
Source: Synapse - August 6, 2009 Category: Neurology Authors: Bin Mei, Lei Niu, Bin Cao, Dake Huang, Yifeng Zhou Source Type: journals

Decreased dendritic spine density of neurons of the prefrontal cortex and nucleus accumbens and enhanced amphetamine sensitivity in postpubertal rats after a neonatal amygdala lesionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
A neonatal basolateral-amygdala (nBLA) lesion in rats could be a potential animal model to study the early neurodevelopmental abnormalities associated with the behavioral and morphological brain changes observed in schizophrenia. Morphological alterations in pyramidal neurons from the prefrontal cortex (PFC) have been observed in postmortem schizophrenic brains, mainly because of decreased dendritic arbor and spine density. We assessed the effects of nBLA-lesion on the dendritic morphology of neurons from the PFC and the nucleus accumbens (NAcc) in rats. nBLA lesions were made on postnatal day 7 (PD7), and later, the dendr...
Source: Synapse - August 6, 2009 Category: Neurology Authors: Oscar Solis, Rubén Antonio Vázquez-Roque, Israel Camacho-Abrego, Citlalli Gamboa, Fidel De La Cruz, Sergio Zamudio, Gonzalo Flores Source Type: journals

Computational analysis of determinants of dopamine (DA) dysfunction in DA nerve terminalsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Dopamine signaling is involved in a number of brain pathways, and its disruption has been suggested to be involved in the several disease states, including Parkinson's disease (PD), schizophrenia, and attention deficit hyperactivity disorder (ADHD). It has been hypothesized that altered storage, release, and reuptake of dopamine contributes to both the hypo- and hyperdopaminergic states that exist in various diseases. Here, we use our recently described mathematical model of dopamine metabolism, combined with a comprehensive Monte Carlo simulation analysis, to identify key determinants of dopamine metabolism associated wit...
Source: Synapse - August 6, 2009 Category: Neurology Authors: Zhen Qi, Gary W. Miller, Eberhard O. Voit Source Type: journals

Inverse agonist histamine H3 receptor PET tracers labelled with carbon-11 or fluorine-18Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Two histamine H3 receptor (H3R) inverse agonist PET tracers have been synthesized and characterized in preclinical studies. Each tracer has high affinity for the histamine H3 receptor, has suitable lipophilicity, and neither is a substrate for the P-glycoprotein efflux pump. A common phenolic precursor was used to synthesize each tracer with high specific activity and radiochemical purity by an alkylation reaction using either [11C]MeI or [18F]FCD2Br. Autoradiographic studies in rhesus monkey and human brain slices showed that each tracer had a widespread distribution with high binding densities in frontal cortex, globus p...
Source: Synapse - August 6, 2009 Category: Neurology Authors: Terence G. Hamill, Nagaaki Sato, Makoto Jitsuoka, Shigeru Tokita, Sandra Sanabria, Waisi Eng, Christine Ryan, Stephen Krause, Norihiro Takenaga, Shil Patel, Zhizhen Zeng, David Williams Jr., Cyrille Sur, Richard Hargreaves, H. Donald Burns Source Type: journals

Different mechanisms of Ca2+ regulation that influence synaptic transmission: Comparison between crayfish and Drosophila neuromuscular junctionsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This study focuses on the mechanisms responsible for the regulation of intracellular calcium concentration ([Ca2+]i) in high output terminals of larval Drosophila compared to a low-output terminal of the crayfish neuromuscular junction (NMJ). Three processes; plasmalemmal Na+/Ca2+ exchanger [NCX], Ca2+-ATPase (PMCA), and sarcoplasmic/endoplasmic Ca2+-ATPase (SERCA) are important in regulating the [Ca2+]i are examined. When the NCX is compromised by reduced [Na+]o, no consistent effect occurred; but a NCX blocker KB-R7943 decreased the excitatory postsynaptic potential (EPSP) amplitudes. Compromising the PMCA with pH 8.8 re...
Source: Synapse - July 30, 2009 Category: Neurology Authors: Mohati Desai-Shah, Robin L. Cooper Source Type: journals

GABAA-benzodiazepine receptor availability in smokers and nonsmokers: Relationship to subsyndromal anxiety and depressionEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Many smokers experience subsyndromal anxiety symptoms while smoking and during acute abstinence, which may contribute to relapse. We hypothesized that cortical gamma aminobutyric acidA-benzodiazepine receptor (GABAA-BZR) availability in smokers and nonsmokers might be related to the expression of subsyndromal anxiety, depressive, and pain symptoms. Cortical GABAA-BZRs were imaged in 15 smokers (8 men and 7 women), and 15 healthy age and sex-matched nonsmokers, and 4 abstinent tobacco smokers (3 men; 1 woman) using [123I]iomazenil and single photon emission computed tomography (SPECT). Anxiety and depressive symptoms were m...
Source: Synapse - July 28, 2009 Category: Neurology Authors: Irina Esterlis, Kelly P. Cosgrove, Jeffery C. Batis, Frederic Bois, Tracy A. Kloczynski, Stephanie M. Stiklus, Edward Perry, Gilles D. Tamagnan, John P. Seibyl, Robert Makuch, Suchitra Krishnan-Sarin, Stephanie O'Malley, Julie K. Staley Source Type: journals

Increased cortical nitric oxide release after phencyclidine administrationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Phencyclidine exerts psychotomimetic effects in humans and is used as a pharmacological animal model for schizophrenia. We, and others, have demonstrated that phencyclidine induces cognitive deficits in rats that are associated with schizophrenia. These cognitive deficits can be normalized by inhibition of nitric oxide synthase. The development of selective microelectrochemical nitric oxide sensors may provide direct evidence for the involvement of nitric oxide in these effects. The aim of the present study was to use LIVE (long term in vivo electrochemistry) to investigate the effect of phencyclidine, alone or in combinat...
Source: Synapse - July 28, 2009 Category: Neurology Authors: Erik Pålsson, Niall Finnerty, Kim Fejgin, Daniel Klamer, Caroline Wass, Lennart Svensson, John Lowry Source Type: journals

Altered expression and alpha-1 adrenergic receptor mediated activity of protein kinase C in the prefrontal cortex of rats with neonatal ventral hippocampus lesionsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The neonatal ventral hippocampus (nVH) lesion in rats captures many features of schizophrenia at the levels of behavior and neurobiological markers. We have previously reported enhanced expression of [alpha]-1 adrenergic receptors (AR) in the prefrontal cortex (PFC) of postpubertal nVH-lesioned rats and proposed that enhanced [alpha]-1 AR signaling might participate in some of the behavioral abnormalities observed in the nVH-lesioned rats. To assess the components of [alpha]-1 adrenergic signaling in nVH-lesiond rats, we examined prefrontal cortical expression of protein kinase C (PKC) subtypes by Western blotting and [alp...
Source: Synapse - July 27, 2009 Category: Neurology Authors: Irina Al-Khairi, Moogeh Baharnoori, Aarthi Kamath, Sanjeev K. Bhardwaj, Lalit K. Srivastava Source Type: journals

Second-by-second analysis of alpha 7 nicotine receptor regulation of glutamate release in the prefrontal cortex of awake ratsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
These experiments utilized an enzyme-based microelectrode selective for the second-by-second detection of extracellular glutamate to reveal the [alpha]7-based nicotinic modulation of glutamate release in the prefrontal cortex (PFC) of freely moving rats. Rats received intracortical infusions of the nonselective nicotinic agonist nicotine (12.0 mM, 1.0 [mu]g/0.4 [mu]l) or the selective [alpha]7 agonist choline (2.0 mM/0.4 [mu]l). The selectivity of drug-induced glutamate release was assessed in subgroups of animals pretreated with the [alpha]7 antagonist, [alpha]-bungarotoxin ([alpha]-BGT, 10 [mu]M), or kynurenine (10 [mu]M...
Source: Synapse - July 26, 2009 Category: Neurology Authors: Åsa Konradsson-Geuken, Clelland R. Gash, Kathleen Alexander, Francois Pomerleau, Peter Huettl, Greg A. Gerhardt, John P. Bruno Source Type: journals

Involvement of Group II mGluRs in mossy fiber LTDEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Mossy fiber long-term depression (LTD) has been shown to be triggered by either pharmacological or synaptic activation of Group II metabotropic glutamate receptors (mGluRs) whereas other studies indicate that synaptic activation of mGluRs is very limited. Therefore, we reexamined the role of Group II mGluRs for the induction of mossy fiber LTD. The complete depression of field potentials (fEPSPs) by 1 [mu]M (2S,2[prime]R,3[prime]R)-2-(2[prime],3[prime]-Dicarboxycyclopropyl)glycine (DCG-IV) only partially reversed upon removal of the drug but fEPSPs were completely restored by the Group II antagonist 2S-2-amino-2-(1S,2S-2-c...
Source: Synapse - July 26, 2009 Category: Neurology Authors: Maria Wostrack, Dirk Dietrich Source Type: journals

Zinc: The brain's dark horseEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
This article provides an overview of zinc neurobiology and reviews the experimental evidence that implicates zinc signals in the pathophysiology of neuropsychiatric diseases. A greater understanding of zinc's role in the central nervous system may therefore allow for the development of therapeutic approaches where aberrant metal homeostasis is implicated in disease pathogenesis. Synapse 63:1029-1049, 2009. © 2009 Wiley-Liss, Inc. (Source: Synapse)
Source: Synapse - July 19, 2009 Category: Neurology Authors: Byron K.Y. Bitanihirwe, Miles G. Cunningham Source Type: journals

Gene expression analysis on anterior temporal neocortex of patients with intractable epilepsyEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
To elucidate the molecular basis of intractable epilepsy (IE), we used a whole-genome transcriptomic approach to identify genes involved in the pathogenesis of this disease. Using a complementary DNAs microarray representing 4096 human genes, we analyzed differential gene expression in the anterior temporal neocortex (ATN) of IE patients relative to control patients who had an operation to relieve head trauma-related intracranial pressure. The results were validated by real-time fluorescence-quantitative polymerase chain reaction (FQ-PCR) and reverse transcription-PCR (RT-PCR). The expression of 143 genes (3.5%) was signif...
Source: Synapse - July 19, 2009 Category: Neurology Authors: Zhi-Qin Xi, Fei Xiao, Jie Yuan, Xue-Feng Wang, Liang Wang, Feng-Yin Quan, Guang-Wei Liu Source Type: journals

Abnormality of synaptic vesicular associated proteins in cerebral cortex and hippocampus after microwave exposureEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Studies were performed to determine the effects of microwave on synaptic vesicles and the expression of synaptic vesicular associated proteins including synapsin I, VAMP-2, syntaxin, and synaptophysin. 25 Wistar rats were exposed to microwave which the average power density was 30 mW/cm2, and whole body average specific absorption rate was 14.1 W/kg for 5 min. Synaptosome preparations in the cerebral cortex and hippocampus were obtained by isotonic Percoll/sucrose discontinuous gradients at 6 h, 1, 3, and 7 days after radiation. The expression of synaptic vesicular associated proteins was measured using Western blots and i...
Source: Synapse - July 13, 2009 Category: Neurology Authors: Lifeng Wang, Ruiyun Peng, Xiangjun Hu, Yabing Gao, Shuiming Wang, Li Zhao, Ji Dong, Zhentao Su, Xinping Xu, Ronglian Gao, Cuiping Lei Source Type: journals

Endocannabinoid modulation of amphetamine sensitization is disrupted in a rodent model of lesion-induced dopamine dysregulationEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
We tested the hypothesis that increased dopaminergic sensitivity induced by olfactory bulbectomy is mediated by dysregulation of endocannabinoid signaling. Bilateral olfactory bulbectomy induces behavioral and neurobiological symptomatology related to increased dopaminergic sensitivity. Rats underwent olfactory bulbectomy or sham operations and were assessed 2 weeks later in two tests of hyperdopaminergic responsivity: locomotor response to novelty and locomotor sensitization to amphetamine. Amphetamine (1 mg/kg i.p.) was administered to rats once daily for 8 consecutive days to induce locomotor sensitization. URB597, an i...
Source: Synapse - July 13, 2009 Category: Neurology Authors: Sarah A. Eisenstein, Philip V. Holmes, Andrea G. Hohmann Source Type: journals

Ex vivo [11C]-(+)-PHNO binding is unchanged in animal models displaying increased high-affinity states of the D2 receptor in vitroEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Dopamine (DA) D2 receptor supersensitivity has been linked to an increase in the density of the D2 high-affinity state as measured in vitro. The two- affinity-state model of the D2 receptor predicts that the ex vivo specific binding of [11C]-(+)-PHNO, an agonist radiotracer thought to bind selectively to the high-affinity state in vivo, should be increased in animal models that display in vitro increases in the proportion of receptors in the D2 high-affinity state. Here, we test this hypotheses by comparing the ex vivo SBR of [11C]-(+)-PHNO with that of the antagonist radiotracer [3H]-raclopride in three dopaminergically s...
Source: Synapse - July 12, 2009 Category: Neurology Authors: Patrick N. McCormick, Shitij Kapur, Greg Reckless, Alan A. Wilson Source Type: journals

Reward-seeking and discrimination deficits displayed by hypodopaminergic mice are prevented in mice lacking dopamine D4 receptorsEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The dopamine D4 receptor (D4R) is predominantly expressed in the prefrontal cortex, a brain area that integrates motor, rewarding, and cognitive information. Because participation of D4Rs in executive learning is largely unknown, we challenged D4R knockout mice (Drd4-/-) and their wild-type (WT) littermates, neonatally treated with 6-hydroxydopamine (6-OHDA; icv) or vehicle in two operant learning paradigms. A continuous reinforcement task, in which one food-pellet was delivered after every lever press, showed that 6-OHDA-treated mice (hypodopaminergic) WT mice pressed the reinforcing lever at much lower rates than normodo...
Source: Synapse - July 12, 2009 Category: Neurology Authors: Sergio I. Nemirovsky, M. Elena Avale, Daniela Brunner, Marcelo Rubinstein Source Type: journals

Differential corticosteroid receptor regulation of mesoaccumbens dopamine efflux during the peak and nadir of the circadian rhythm: A molecular equilibrium in the midbrain?Email this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
Corticosteroid receptor modulation of mesoaccumbens dopamine neurotransmission is believed to be a key neurobiological mechanism mediating the effects of stress in addiction. Importantly, nucleus accumbens (NAc) subregions (core and shell) are reported to respond differentially to fluctuating basal levels of glucocorticoids, with dopaminergic responses in the core of the NAc being somewhat impervious to fluctuating levels of glucocorticoids relative to the shell. To investigate the corticosteroid receptor mechanisms mediating basal dopamine efflux in the core of the NAc, we have used chronoamperometry in combination with s...
Source: Synapse - July 12, 2009 Category: Neurology Authors: Susannah J. Tye, Anthony D. Miller, Charles D. Blaha Source Type: journals

Deficits in substance P mRNA levels in the CeA are inversely associated with alcohol-motivated respondingEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
In the present study, in vitro and in vivo studies were conducted to determine the relationship between innate substance P (SP) levels and alcohol-motivated behavior in alcohol-preferring (P) and nonpreferring (NP) rat lines. In Experiment 1, in situ hybridization and quantitative autoradiography were used to detect and measure SP mRNA levels in discrete brain loci of the P and NP rats. The results indicated significantly lower SP mRNA levels in the central nucleus of the amygdala (CeA) of P compared with those of NP rats. Experiment 2 evaluated the effects of SP, microinfused into the CeA, on alcohol (10%, v/v) and sucros...
Source: Synapse - July 9, 2009 Category: Neurology Authors: Andrew Rong Song Tzeng Yang, Heon Soo Yi, Jacek Mamczarz, Harry L. June Jr, Bang H. Hwang, Harry L. June Sr Source Type: journals

Evaluation of N-benzyl-N-[11C]methyl-2- (7-methyl-8-oxo-2-phenyl-7,8-dihydro-9H-purin-9-yl)acetamide ([11C]DAC) as a novel translocator protein (18 kDa) radioligand in kainic acid-lesioned ratEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The aim of this study was to evaluate N-benzyl-N-[11C]methyl-2-(7-methyl-8-oxo-2-phenyl-7,8-dihydro-9H-purin-9-yl)acetamide ([11C]DAC) as a new translocator protein (18 kDa) [TSPO, formerly known as the peripheral-type benzodiazepine receptor (PBR)] positron emission tomography (PET) ligand in normal mice and unilateral kainic acid (KA)-lesioned rats. DAC is a derivative of AC-5216, which is a potent and selective PET ligand for the clinical investigation of TSPO. The binding affinity and selectivity of DAC for TSPO were similar to those of AC-5216, and DAC was less lipophilic than AC-5216. The distribution pattern of [11C...
Source: Synapse - July 9, 2009 Category: Neurology Authors: Kazuhiko Yanamoto, Tomoteru Yamasaki, Katsushi Kumata, Joji Yui, Chika Odawara, Kazunori Kawamura, Akiko Hatori, Osamu Inoue, Masatoshi Yamaguchi, Kazutoshi Suzuki, Ming-Rong Zhang Source Type: journals

In vivo measurement of somatodendritic release of dopamine in the ventral tegmental areaEmail this article to a colleague. Save this article to My Clippings. Discuss or comment on this article.
The ventral tegmental area (VTA), the locus of mesolimbic dopamine cell bodies, contains dopamine. Experiments in brain slices have demonstrated that VTA dopamine can be released by local electrical stimulation. Measurements with both push-pull cannula and microdialysis in intact animals have also obtained evidence for releasable dopamine. Here we demonstrate that dopamine release in the VTA can be evoked by remote stimulations of the medial forebrain bundle (MFB) in the anesthetized rat. In initial experiments, the MFB was electrically stimulated while a carbon-fiber electrode was lowered to the VTA, with recording by fas...
Source: Synapse - July 9, 2009 Category: Neurology Authors: Justin M. Kita, Brian M. Kile, Lauren E. Parker, R. Mark Wightman Source Type: journals