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 'The Journal of Comparative Neurology' source. Wed, 08 Feb 2012 20:43:37 +0100 http://www.medworm.com/index.php?rid=5668732&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22784 AbstractSea snakes have evolved numerous anatomical, physiological, and behavioral adaptations to suit their wholly aquatic lifestyle. However, although sea snakes use vision for foraging and mate selection, little is known about their visual abilities. We used microspectrophotometry, light microscopy, and scanning electron microscopy to characterize the retinal photoreceptors of spine‐bellied (Lapemis curtus) and horned (Acalyptophis peronii) sea snakes. Both species have three types of visual pigment sensitive to short (SWS; wavelength of maximum absorbance, λmax 428–430 nm), medium (MWS; λmax 496 nm), and long wavelengths of light (LWS; λmax 555–559 nm) in each of three different subtypes of cone‐like single photoreceptor. They also possess a cone‐like double photoreceptor ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668732 Thu, 09 Feb 2012 01:21:45 +0100 5668732 http://www.medworm.com/index.php?rid=5668731&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22771 AbstractInhibitory and excitatory synaptic inputs onto trigeminal motoneurons play an important role in coordinating jaw movements. Previously, we reported that the phenotype of the inhibitory boutons apposing the somata of jaw‐closing (JC) motoneurons changes from γ‐aminobutyric acid (GABA)‐positive (GABA+) to predominantly glycine‐positive (Gly+) during development. In the present study, we investigated the development of inhibitory and excitatory boutons apposing antagonistic jaw‐opening (JO) motoneurons (anterior digastric motoneurons) at postnatal day 2 (P2), P11, and P31 in the rat. JO motoneurons were retrogradely labeled with horseradish peroxidase. Postembedding immunogold staining with antisera against GABA, Gly, and glutamate (Glut) was performed and followed by quant... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668731 Thu, 09 Feb 2012 01:21:43 +0100 5668731 http://www.medworm.com/index.php?rid=5668730&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22761 This study examined the hypothalamus of 51 rhesus monkeys (23 male, 18 female, 6.5–31 years old) using design‐based stereology to obtain unbiased estimates of neuron and glia numbers and the Cavalieri method to estimate volumes for eight reference spaces: total unilateral hypothalamus, suprachiasmatic nucleus (SCN), supraoptic nucleus (SON), paraventricular nucleus (PVN), dorsomedial nucleus (DM), ventromedial nucleus (VM), medial mammillary nucleus (MMN), and lateral hypothalamic area (LHA). The results demonstrated no age‐related difference in neuron number, glia number, or volume in any area in either sex except the PVN of male monkeys, which showed a significant increase in both neuron and glia numbers with age. Comparison of males and females for sexual dimorphisms revealed no s... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668730 Thu, 09 Feb 2012 01:21:40 +0100 5668730 http://www.medworm.com/index.php?rid=5668729&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22743 AbstractThe rhythmic phenomena expressed by organisms change over their lifetimes, but little is known of accompanying reorganization of the central circadian timing system in the brain. Especially dramatic changes in overt rhythms and morphology occur during transformation of larval insects into the adult form (metamorphosis). In Rhodnius prolixus, both the physiology of metamorphosis and its hormonal control are known in detail. Here we report changes in the brain timing system as revealed by pigment dispersing factor immunohistochemistry and confocal microscopy. Most of the features of the larval system are retained, but new clock cells differentiate and the arborizations of their axons increase in complexity, as do pathways connecting the lateral (LNs) and dorsal (DNs) groups of clock ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668729 Thu, 09 Feb 2012 01:21:38 +0100 5668729 http://www.medworm.com/index.php?rid=5668728&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23055 AbstractConfocal image of the relative distribution of the Mel1b melatonin receptor (green) and the ON bipolar cell marker guanine nucleotide binding protein alpha, Go α (red) in the retina of Xenopus laevis. Mel1b receptor immunoreactivity is absent from the cell bodies of ON bipolar cells, identifying the Mel1b receptorimmunoreactive bipolar cells as OFF bipolar cells. The Journal of Comparative Neurology, Volume 520, Number 6, pages 1115–1127. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668728 Thu, 09 Feb 2012 01:21:34 +0100 5668728 http://www.medworm.com/index.php?rid=5668716&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23064 AbstractThe connections of the lateral hypothalamic area juxtadorsomedial region (LHAjd) were investigated in a series of pathway‐tracing experiments involving iontophoretic co‐injection of the tracers PhaPhaseolus vulgarisseolus vulgaris leucoagglutinin (PHAL—for outputs) and cholera toxin B subunit (CTB—for inputs). Results revealed the LHAjd has connections with some 318 distinct gray matter regions encompassing all four subsystems—motor, sensory, cognitive and behavioral state—included in a basic structure‐function network model of the nervous system. Coordination of these subsystems is vital to the control of emotion and behavior, and in this regard the connections of the LHAjd indicate that it may have a prominent mechanistic role. Furthermore, the LHAjd connections in ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668716 Thu, 09 Feb 2012 01:20:06 +0100 5668716 http://www.medworm.com/index.php?rid=5668727&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23070 In this study, we demonstrate that spine clusters do exist on pyramidal neurons by analyzing the three‐dimensional locations of ∼40,000 spines on 280 apical dendritic branches in layer III of the rhesus monkey prefrontal cortex. Using clustering algorithms and Monte Carlo simulations, we quantify the probability that the observed extent of clustering does not occur randomly. This provides a measure that tests for spine clustering on a global scale, whenever high‐resolution morphologic data are available. Here, we demonstrate that spine clusters occur significantly more frequently than expected by pure chance, and that spine clustering is concentrated in apical terminal branches. Importantly, these findings indicate that spine clustering is driven by systematic biological processes. W... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668727 Wed, 08 Feb 2012 05:00:00 +0100 5668727 http://www.medworm.com/index.php?rid=5668726&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23069 AbstractThe chorda tympani (CT) nerve innervates lingual taste buds and is susceptible to damage during dental and inner ear procedures. Interruption of the CT results in a disappearance of taste buds, which can be accompanied by taste disturbances. Because the CT usually regenerates to reinnervate taste buds successfully in a few weeks, a persistence of taste disturbances may indicate alterations in central nervous function. Peripheral injury to other sensory nerves leads to glial responses at central terminals, which actively contribute to abnormal sensations arising from nerve damage. Therefore, the current study examined microglial and astrocytic responses in the first central gustatory relay –the nucleus of the solitary tract (nTS)‐ after transection of the CT. Damage to the CT re... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668726 Wed, 08 Feb 2012 05:00:00 +0100 5668726 http://www.medworm.com/index.php?rid=5668725&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23068 AbstractIn daylight vision, parallel processing starts at the cone synapse. Cone signals flow to On and Off bipolar cells, which are further divided into types according to morphology, immunocytochemistry, and function. The axons of the bipolar cell types stratify at different levels in the inner plexiform layer (IPL), and can interact with costratifying amacrine and ganglion cells. These interactions endow the ganglion cell types with unique functional properties. The wiring that underlies the interactions between bipolar, amacrine, and ganglion cells is poorly understood. It may be easier to elucidate this wiring if organizational rules can be established. We identify 13 types of cone bipolar cells in the ground squirrel, 11 of which contact contiguous cones with the possible exception o... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668725 Wed, 08 Feb 2012 05:00:00 +0100 5668725 http://www.medworm.com/index.php?rid=5668724&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23067 AbstractSynaptic function depends upon interactions among sets of proteins that assemble into complex supramolecular machines. Molecular biology, electrophysiology and live‐cell imaging studies have provided tantalizing glimpses into the inner workings of the synapse, but fundamental questions remain regarding the functional organization of these “nano‐machines.” Electron tomography reveals the internal structure of synapses in three dimensions with exceptional spatial resolution. Here we report results from an electron tomographic study of axospinous synapses in neocortex and hippocampus of the adult rat, based on aldehyde‐fixed material stabilized with tannic acid in lieu of postfixation with osmium tetroxide. Our results provide a new window into the structural basis of excita... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668724 Wed, 08 Feb 2012 05:00:00 +0100 5668724 http://www.medworm.com/index.php?rid=5668723&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23066 AbstractTreatment with testosterone is neuroprotective/neurotherapeutic after a variety of motoneuron injuries. Here we assessed if testosterone might have similar beneficial effects after spinal cord injury (SCI). Young adult female rats received either sham or T9 spinal cord contusion injuries and were implanted with blank or testosterone‐filled Silastic capsules. Four weeks later, motoneurons innervating the vastus lateralis muscle of the quadriceps were labeled with cholera toxin‐conjugated HRP, and dendritic arbors were reconstructed in 3 dimensions. Soma volume, motoneuron number, lesion volume, and tissue sparing were also assessed, as were muscle weight, fiber cross‐sectional area, and motor endplate size and density. Contusion injury resulted in large lesions, with no signif... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668723 Wed, 08 Feb 2012 05:00:00 +0100 5668723 http://www.medworm.com/index.php?rid=5668722&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23063 AbstractOptical insulation plays a critical role in the fine visual acuity of the Drosophila compound eye. Screening pigments expressed by a number of cell types contribute to this phenomenon. They provide optical insulation that prevents extraneous light rays from inappropriately activating the photoreceptors. This optical insulation can be divided into two categories; the insulation of the individual ommatidia, and the insulation of the compound eye as a whole. The whole‐eye insulation is provided by two sources. The sides of the eye are optically insulated by the pigment rim, a band of pigment cells that circumscribes the eye. The base of the eye is insulated by the subretinal pigment layer; a thick layer of pigment that lies directly underneath the retina. How this subretinal pigment... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668722 Wed, 08 Feb 2012 05:00:00 +0100 5668722 http://www.medworm.com/index.php?rid=5668721&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23061 AbstractThe posterodorsal medial amygdala (MePD) exhibits numerous sex differences including differences in volume and in the number and morphology of neurons and astroctyes. In adulthood, gonadal hormones, including both androgens and estrogens, have been shown to play a role in maintaining the masculine character of many of these sex differences, but whether adult gonadal hormones maintain the increased number and complexity of astrocytes in the male MePD was unknown. To answer this question, we examined astrocytes in the MePD of male and female Long Evans rats that were gonadectomized as adults and treated for 30 days with either testosterone or a control treatment. At the end of treatment, brains were collected and immunostained for glial fibrillary acidic protein (GFAP). Stereological... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668721 Wed, 08 Feb 2012 05:00:00 +0100 5668721 http://www.medworm.com/index.php?rid=5668720&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23060 AbstractIn the rabbit retina, there are two types of horizontal cell (HC). A‐type HCs (AHC) are axonless and extensively coupled via C×50 gap junctions. The B‐type HC (BHC) is axon‐bearing; the somatic dendrites form a second network coupled by gap junctions while the axon terminals (ATs) form a third independent network in the outer plexiform layer (OPL). The mouse retina has only one type of HC which is morphologically similar to the B‐type HC of the rabbit. Previous work suggested that mouse HCs express C×57 (Hombach et al., 2004). Therefore, we cloned rabbit C×57 and raised an antibody to determine the distribution of C×57 gap junctions among rabbit HCs. Dye injection methods were used to obtain detailed fills for all three horizontal cell networks for analysis by confocal ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668720 Wed, 08 Feb 2012 05:00:00 +0100 5668720 http://www.medworm.com/index.php?rid=5668719&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23059 AbstractMalacostracan crustaceans and dicondylic insects possess large second‐order olfactory neuropils called, respectively, hemiellipsoid bodies and mushroom bodies. Because these centers look very different in the two groups of arthropods, it has been debated whether these second‐order sensory neuropils are homologous or whether they have evolved independently. Here we describe the results of neuroanatomical observations and experiments that resolve the neuronal organization of the hemiellipsoid body in the terrestrial Caribbean hermit crab, Coenobita clypeatus, and compare this organization with the mushroom body of an insect, the cockroach Periplaneta americana. Comparisons of the morphology, ultrastructure, and immunoreactivity of the hemiellipsoid body of C. clypeatus and the mu... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668719 Wed, 08 Feb 2012 05:00:00 +0100 5668719 http://www.medworm.com/index.php?rid=5668718&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23057 AbstractThe anterior thalamic nuclei consist of the anterodorsal (AD), anteroventral, and anteromedial nuclei, each of which are highly differentiated and may contribute to different aspects of various cognitive and memory functions. In particular, the AD is unique in that it is implicated in learning at the earliest stage of discriminative avoidance conditioning in the rabbit. To better understand the functional roles played by the AD in memory and learning processes, we analyzed the organization of thalamocortical projections of the AD in the rabbit, using the anterograde tracer biotinylated dextran amine and the retrograde tracer cholera toxin subunit b. The data show that the AD provides strong projections to layers I and IV of area 30 and to layers I, III, IV, and VI of area 29 in the... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668718 Wed, 08 Feb 2012 05:00:00 +0100 5668718 http://www.medworm.com/index.php?rid=5668717&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23056 AbstractThe majority of spinal cord injuries (SCIs) in the clinic occur at the lower cervical levels, resulting in both white and gray matter disruption. In contrast, most experimental models of spinal cord injury (SCI) in rodents induce damage in the thoracic cord, resulting primarily in white matter disruption. To address this disparity, experimental cervical SCI models have been developed. Thus, we utilized a recently characterized model of cervical hemicontusion SCI in adult male rats to assess the potential therapeutic effect of post‐SCI administration of 17β‐estradiol. Rats received a hemicontusion at the level of the fifth cervical vertebra (C5) followed by administration of 17β‐estradiol via a slow release pellet (0.5 or 5.0mg/pellet) beginning at 30 minutes post‐SCI. Beh... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5668717 Wed, 08 Feb 2012 05:00:00 +0100 5668717 http://www.medworm.com/index.php?rid=5630537&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23054 AbstractEach fall, eastern North American monarch butterflies (Danaus plexippus) use a time‐compensated sun compass to migrate to their overwintering grounds in central Mexico. The sun compass mechanism involves the neural integration of skylight cues with information from circadian clocks to maintain a constant heading. The neuronal substrates for the necessary interactions between compass neurons in the central complex, a prominent structure of the central brain, and circadian clocks are largely unknown. To begin to unravel these neural substrates, we performed three‐dimensional reconstructions of all neuropils of the monarch brain based on anti‐synapsin labeling. Our work characterizes 21 well‐defined neuropils (19 paired, 2 unpaired), as well as all synaptic regions between the... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5630537 Fri, 27 Jan 2012 01:38:48 +0100 5630537 http://www.medworm.com/index.php?rid=5599433&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22766 In this study, we addressed the topographic distribution and amino acid neurotransmitter phenotype of endocannabinoid‐sensitive hypothalamic neurons in mice. The in situ hybridization detection of CB1 mRNA revealed high levels of expression in the medial septum (MS) and the diagonal band of Broca (DBB), moderate levels in the preoptic area and the hypothalamic lateroanterior (LA), paraventricular (Pa), ventromedial (VMH), lateral mammillary (LM), and ventral premammillary (PMV) nuclei, and low levels in many other hypothalamic regions including the suprachiasmatic (SCh) and arcuate (Arc) nuclei. This regional distribution pattern was compared with location of γ‐aminobutyric acid (GABA)ergic and glutamatergic cell groups, as identified by the expression of glutamic acid decarboxylase 6... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599433 Wed, 18 Jan 2012 02:09:15 +0100 5599433 http://www.medworm.com/index.php?rid=5599432&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23036 AbstractA hippocampal neuron in primary culture stained with anti‐PIST (red) and anti‐neuroligin‐2 (green), a postsynaptic cell adhesion protein which is exclusively located at inhibitory synapses. The nucleus was stained with DAPI (blue). Note the typical distribution of neuroligin‐2 immunoreactivity reminiscent of inhibitory synapses at proximal dendrites and cell body, which is not matched by the PIST immunofluorescence signal. The latter is concentrated in the perikaryon in a juxtanuclear position and appears to be absent from postsynaptic sites. The Journal of Comparative Neurology, Volume 520, Number 5, pages 889–913. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599432 Wed, 18 Jan 2012 02:09:05 +0100 5599432 http://www.medworm.com/index.php?rid=5599415&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23052 AbstractThe continuous replacement of neurons in the olfactory epithelium provides an advantageous model for investigating neuronal differentiation and maturation. By calculating the relative enrichment of every mRNA detected in samples of mature mouse olfactory sensory neurons (OSNs), immature OSNs, and the residual population of neighboring cell types, then comparing these ratios against the known expression patterns of >300 genes, enrichment criteria that accurately predicted the OSN expression patterns of nearly all genes were determined. 847 immature OSN‐specific and 691 mature OSNspecific genes were identified. Control of gene expression by chromatin modification and transcription factors, along with neurite growth, protein transport, RNA processing, cholesterol biosynthesis, an... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599415 Wed, 18 Jan 2012 02:07:23 +0100 5599415 http://www.medworm.com/index.php?rid=5599417&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23053 AbstractThe Etruscan shrew, Suncus etruscus, is one of the smallest mammals. Etruscan shrews can recognize prey shape with amazing speed and accuracy, based on whisker‐mediated tactile cues. Because of its small size quantitative analysis of the Etruscan shrew cortex is more tractable than in other animals. To quantitatively assess the anatomy of the Etruscan shrew's brain we sectioned brains and applied Nissl staining and NeuN (neuronal nuclei) antibody staining. On basis of these stains we estimated the number of neurons of ten cortical hemispheres using Stereoinvestigator and Neurolucida (MBF Bioscience) software. On average the neuron number per hemisphere was found to be ∼ 1 million. We also measured cortical surface area and found an average of 11.1 mm2 (n = 7) and an average vol... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599417 Tue, 17 Jan 2012 05:00:00 +0100 5599417 http://www.medworm.com/index.php?rid=5599416&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23051 We examined the localization of GIRK2 in the SN and adjacent ventral tegmental area (VTA) of humans and mice using either neuromelanin pigment or immunolabeling with tyrosine hydroxylase (TH) or calbindin. GIRK2 immunoreactivity was found in nearly every human pigmented neuron or mouse TH‐immunoreactive neuron in both the SN and VTA, although considerable variability in the intensity of GIRK2 staining was observed. The relative intensity of GIRK2 immunoreactivity in TH‐immunoreactive neurons was determined and in both species nearly all SN TH‐immunoreactive neurons had strong GIRK2 immunoreactivity compared with only 50‐60% of VTA neurons. Most paranigral VTA neurons also contained calbindin immunoreactivity and approximately 25% of these and nearby VTA neurons also had strong GIRK... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599416 Tue, 17 Jan 2012 05:00:00 +0100 5599416 http://www.medworm.com/index.php?rid=5599418&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23043 AbstractMultiple lines of evidence document a role for glutamatergic input to the hypothalamic paraventricular nucleus (PVH) in stress‐induced activation of the hypothalamic‐pituitary‐adrenocortical (HPA) axis. However, the neuroanatomical origins of the glutamatergic input have yet to be definitively determined. We have previously shown that Vesicular Glutamate Transporter 2; VGLUT2) is the predominant VGLUT isoform expressed in the basal forebrain and brainstem, including PVH‐projecting regions, and that the PVH is preferentially innervated by VGLUT2‐immunoreactive terminals/boutons. In the present study we employed a dual‐labeling approach, combining immunolabeling for a retrograde tract‐tracer, Fluoro‐gold (FG), with in situ hybridization for VGLUT2 mRNA, to map the bra... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599418 Sun, 15 Jan 2012 05:00:00 +0100 5599418 http://www.medworm.com/index.php?rid=5599420&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23049 AbstractAscending pathways to the telencephalon from the secondary gustatory nucleus (SGN), preglomerular tertiary gustatory nucleus (pTGN) and medial preglomerular nucleus (PGm) were examined by tract‐tracing experiments in goldfish Carassius auratus. Tracer injections to the SGN suggest the presence of direct ascending pathways to the supracommissural and the dorsal parts of ventral telencephalic area, and the medial part of dorsal telencephalic area (Dm), restricted to its ventral region. The SGN experiments also suggest projections to the pTGN and PGm, and several neuronal types in the primary gustatory centers were newly found to give rise to ascending fibers to the SGN. Injections to the pTGN suggest reciprocal connections of the nucleus with the dorsal region of Dm (dDm). Injectio... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599420 Fri, 13 Jan 2012 05:00:00 +0100 5599420 http://www.medworm.com/index.php?rid=5599419&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23047 This study investigated the synaptic connectivity of identified amygdalocortical boutons (ACBs), (labelled anterogradely following injections of Phaseolus vulgaris leucoagglutinin into the basolateral nucleus of the amygdala), with the dendritic processes of identified layer 5 corticospinal neurones in rat mPFC. The corticospinal (CS) neurones in mPFC had been retrogradely labelled with rhodamine fluorescent latex microspheres and subsequently intracellularly ‘filled’ with biotinylated lucifer yellow to visualise their basal and apical dendrites.Two main classes of mPFC CS neurones were identified – Type 1 cells had apical dendrites bearing numerous dendritic spines with radiate basal dendritic arbors. Type 2 cells possessed apical dendrites with greatly reduced spine densities and a... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599419 Fri, 13 Jan 2012 05:00:00 +0100 5599419 http://www.medworm.com/index.php?rid=5599431&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23046 This study provides quantitative data on the extent of gyrencephaly in the large brained African elephant and several species of cetaceans (from smaller to larger brained) in comparison to other mammals. Across three mammalian orders (primates, carnivores and artiodactyls) the species with the larger brains are more gyrencephalic with each order exhibiting a specific negative allometry. The African elephant, with a 5 kg brain, has a gyrencephalic index (GI) of 3.89, which while highly gyrencephalic is not more so than would be predicted for a mammal with a 5 kg brain. The cetaceans had an average GI of 5.43, are the most gyrencephalic mammals studied to date and are more gyrencephalic than one would predict based in comparison to other mammals. No relationship between brain mass and GI was... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599431 Wed, 11 Jan 2012 05:00:00 +0100 5599431 http://www.medworm.com/index.php?rid=5599430&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23045 In conclusion, we show the anatomical organization typical of premature Y‐type retinal ganglion cells persists into adulthood even if normal visual experience follows for years upon an initial six month‐period of BD. Binocular pattern deprivation possibly induces a life‐long OFF functional domination, normally only apparent during development, putting early high quality vision forward as a premise for proper ON‐OFF pathway segregation. These new observations for pattern‐deprived animals provide an anatomical basis for the well‐described motion perception deficits in congenital cataract patients. J. Comp. Neurol., 2012. © 2012 Wiley‐Liss, Inc. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599430 Wed, 11 Jan 2012 05:00:00 +0100 5599430 http://www.medworm.com/index.php?rid=5599429&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23044 AbstractChorda tympani nerve transection (CTX) has been useful to study the relationship between the nerve and taste buds in fungiform papillae. This work demonstrated that the morphological integrity of taste buds depends on their innervation. While considerable research focused on the effects of CTX on peripheral gustatory structures, much less research has focused on the central effects. Here, we explored how CTX affects ganglion cell survival, maintenance of injured peripheral axons, and its terminal field organization in the nucleus of the solitary tract (NTS). Following CTX in adult rats, the chorda tympani nerve was labeled with biotinylated dextran amine at 3, 7, 14, 30, and 60 days post CTX to enable visualization of the terminal field associated with peripheral processes. There w... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599429 Wed, 11 Jan 2012 05:00:00 +0100 5599429 http://www.medworm.com/index.php?rid=5599428&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23042 AbstractVisceral pain following infection or inflammation is a major clinical problem. Although we have knowledge regarding how peripheral endings of colonic afferents change in disease, their central projections have been overlooked. Using neuroanatomical tracing and colorectal distension (CRD) we aimed to identify colonic afferent central terminals (CACTs), the dorsal horn (DH) neurons activated by colonic stimuli in the thoracolumbar (T10‐L1) DH, and determine how they are altered by post‐inflammatory chronic colonic mechanical hypersensitivity. Retrograde tracing from the colon identified CACTs in the DH, whilst immunohistochemistry for phosphorylated MAP kinase ERK1/2 (pERK) identified DH neurons activated by CRD (80 mmHg). In healthy mice, CACTs were primarily located in DH lamin... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599428 Wed, 11 Jan 2012 05:00:00 +0100 5599428 http://www.medworm.com/index.php?rid=5599427&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23041 This study employed a lentiviral tracing technique which expresses green fluorescent protein behind a promoter selective to noradrenergic and adrenergic neurons. Microinjection of this virus into the C3 nucleus enabled the selective tracing of C3 efferents throughout the rat CNS, thus revealing the anatomical framework of C3 projections. C3 terminal fields were observed in over forty different CNS nuclei, spanning all levels of the spinal cord, as well as various medullary, mesencephalic, hypothalamic, thalamic, and telencephalic nuclei. The highest densities of C3 axon varicosities were observed in Lamina X and the intermediolateral cell column of the thoracic spinal cord, as well as the dorsomedial medulla (both commissural and medial nuclei of the solitary tract, area postrema, and the ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599427 Wed, 11 Jan 2012 05:00:00 +0100 5599427 http://www.medworm.com/index.php?rid=5599426&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23040 AbstractDespite recent progress in fluorescence microscopy techniques, electron microscopy (EM) is still superior in the simultaneous analysis of all tissue components at high resolution. However, it is unclear to what extent conventional fixation for EM using aldehydes results in tissue alteration. Here, we made an attempt to minimize tissue alteration by using rapid high‐pressure freezing (HPF) of hippocampal slice cultures. We used this approach to monitor fine‐structural changes at hippocampal mossy fiber synapses associated with chemically induced long‐term potentiation (LTP). Synaptic plasticity in LTP has been known to involve structural changes at synapses including reorganization of the actin cytoskeleton and de novo formation of spines. While LTP‐induced formation and gro... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599426 Wed, 11 Jan 2012 05:00:00 +0100 5599426 http://www.medworm.com/index.php?rid=5599425&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23039 We examined this question by use of both physiological and anatomical approaches in the cat. Intracellular records from antidromically activated levator motoneurons revealed that periorbital electrical stimulation produced bilateral, long latency IPSPs. Central electrical stimulation of the principal trigeminal nucleus produced shorter latency IPSPs. Intracellular staining revealed that these motoneurons reside in the caudal central subdivision and have 10 or more poorly branched dendrites, which extend bilaterally into the surrounding supraoculomotor area. Axons penetrated in this region could be activated from periorbital and central electrodes.Neurons labeled from tracer injections into the caudal oculomotor complex were distributed in a crescent‐shaped band that lined the ventral and... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599425 Wed, 11 Jan 2012 05:00:00 +0100 5599425 http://www.medworm.com/index.php?rid=5599424&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23038 AbstractThe medial superior olive (MSO) is a key auditory brainstem structure that receives binaural inputs and is implicated in processing interaural time disparities used for sound localization. The deaf white cat, a proven model of congenital deafness, was used to examine how deafness and cochlear implantation affected the synaptic organization at this binaural center in the ascending auditory pathway. The patterns of axosomatic and axodendritic organization were determined for principal neurons from the MSO of hearing, deaf, and deaf cats with cochlear implants. The nature of the synapses was evaluated through electron microscopy, ultrastructure analysis of the synaptic vessels and immunohistochemistry. Results show that the proportion of inhibitory axosomatic terminals was significant... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599424 Wed, 11 Jan 2012 05:00:00 +0100 5599424 http://www.medworm.com/index.php?rid=5599423&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23037 AbstractTo investigate how sensory information is processed, transformed, and stored within an olfactory system, we examined the anatomy of the input region, the calyx, of the mushroom bodies of Drosophila melanogaster. These paired structures are important for various behaviors, including olfactory learning and memory. Cells in the input neuropile, the calyx, are organized into an array of microglomeruli each comprising the large synaptic bouton of a projection neuron (PN) from the antennal lobe surrounded by tiny postsynaptic neurites from intrinsic Kenyon cells. Extrinsic neurons of the mushroom body also contribute to the organization of microglomeruli. We employed a combination of genetic reporters to identify single cells in the Drosophila calyx by light microscopy, and compared thes... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599423 Wed, 11 Jan 2012 05:00:00 +0100 5599423 http://www.medworm.com/index.php?rid=5599422&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23050 We report here on experiments that use rabies virus injections into V4 to retrogradely label mono and disynaptic inputs. We find only a small number of labeled neurons in the LGN in a pattern consistent with monosynaptic labeling of koniocells, rather than disynaptic labeling of magno and parvocells. The lack of robust magno and parvocellular label was not due to ineffective viral transport since in the same cases we find hundreds of neurons labeled in the thalamic reticular nucleus, a structure which can only be labeled disynaptically from cortex. We also find a complete absence of neurons labeled in V1, but thousands in adjacent areas V2 and V3. This result helps explain the absence of labeled magno and parvocells in LGN because disynaptic transport from an extrastriate visual area shoul... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599422 Wed, 11 Jan 2012 05:00:00 +0100 5599422 http://www.medworm.com/index.php?rid=5599421&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23048 In this study, we examined the effects of MDMA on the expression of brain‐derived neurotrophic factor (BDNF) and neurotrophin‐3 (NT‐3) and their respective high affinity receptors, trkB and trkC, in multiple regions of the rat brain. A serotonergic‐depleting dose of MDMA (10 mg/kg × 4 at 2‐hour intervals on a single day) was administered to adult Sprague‐Dawley rats and brains were examined 1, 7, or 24 hours after the last dose. Messenger RNA levels of BDNF, NT‐3, trkB and trkC were analyzed using in situ hybridization with cRNA probes. The prefrontal cortex was particularly vulnerable to MDMA‐induced alterations in that BDNF, NT‐3, trkB and trkC mRNAs were all upregulated at multiple time points. MDMA‐treated animals had increased BDNF expression in the frontal, parie... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5599421 Wed, 11 Jan 2012 05:00:00 +0100 5599421 http://www.medworm.com/index.php?rid=5573080&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22773 AbstractCones are critically dependent on interphotoreceptor retinoid‐binding protein (IRBP) for retinoid delivery in the visual cycle. Cone‐dominant vertebrates offer an opportunity to uncover the molecular basis of IRBP's role in this process. Here, we explore the association of IRBP with the interphotoreceptor matrix (IPM) of cones vs. rods in cone dominant retinas from chicken (Gallus domesticus), turkey (Meleagris gallopavo), and pig (Sus scrofa). Retinas were detached and fixed directly or washed in saline prior to fixation. Disassociated photoreceptors with adherent matrix were also prepared. Under 2 mM CaCl2, insoluble matrix was delaminated from saline washed retinas. The distribution of IRBP, as well as glycans binding peanut agglutinin (cone matrix) and wheat germ agglutinin... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5573080 Mon, 09 Jan 2012 00:59:17 +0100 5573080 http://www.medworm.com/index.php?rid=5573079&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22765 AbstractSeveral subtypes of melanopsin‐expressing, intrinsically photosensitive retinal ganglion cells (ipRGCs) have been reported. The M1 type of ipRGCs exhibit distinct properties compared with the remaining (non‐M1) cells. They differ not only in their soma size and dendritic arbor, but also in their physiological properties, projection patterns, and functions. However, it is not known how these differences arise. We tested the hypothesis that M1 and non‐M1 cells express Brn3 transcription factors differentially. The Brn3 family of class IV POU‐domain transcription factors (Brn3a, Brn3b, and Brn3c) is involved in the regulation of differentiation, dendritic stratification, and axonal projection of retinal ganglion cells during development. By using double immunofluorescence for ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5573079 Mon, 09 Jan 2012 00:59:15 +0100 5573079 http://www.medworm.com/index.php?rid=5573078&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22745 AbstractA multitude of potential neurotransmitters and neuromodulators, including peptides, have been detected in the antennal lobe (AL), the first synaptic relay of the central olfactory pathway in the insect brain. However, the functional role of neuropeptides in this system has yet to be revealed. An important prerequisite to understanding the role of neuropeptides is to match the functionally different cell types in the AL with their peptide profiles by using electrophysiological recordings combined with immunocytochemical studies and/or single‐cell mass spectrometry. The olfactory system of Periplaneta americana is particularly well suited to accomplish this goal because several physiologically distinct neuron types can be unequivocally identified. With the aim to analyze the neurop... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5573078 Mon, 09 Jan 2012 00:59:13 +0100 5573078 http://www.medworm.com/index.php?rid=5573077&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23035 AbstractConfocal image of a locust brain 14 days after one antenna had been crushed. Antennal afferents were anterogradely labeled with Neurobiotin (magenta). Aberrantly regenerated olfactory receptor axons have grown through the antennocerebral tract into the mushroom body. Counterstaining: phalloidin (green) and DAPI (blue). The Journal of Comparative Neurology, Volume 520, Number 4, pages 679‐693. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5573077 Mon, 09 Jan 2012 00:59:11 +0100 5573077 http://www.medworm.com/index.php?rid=5506775&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23023 AbstractAbnormal development of the amygdala has been linked to several neurodevelopmental disorders, including schizophrenia and autism. However, the postnatal development of the amygdala is not easily explored at the cellular level in humans. Here, we performed a stereological analysis of the macaque monkey amygdala in order to characterize the cellular changes underlying its normal structural development in primates. The lateral, basal and accessory basal nuclei exhibited the same developmental pattern, with a large increase in volume between birth and three months of age, followed by slower growth continuing beyond one year of age. In contrast, the medial nucleus was near adult size at birth. At birth, the volume of the central nucleus was half of the adult value; this nucleus exhibite... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506775 Fri, 16 Dec 2011 13:42:42 +0100 5506775 http://www.medworm.com/index.php?rid=5506776&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23024 AbstractThe pontine noradrenergic cell groups, A5, A6 (locus coeruleus), and A7, provide the only noradrenergic innervation of the spinal cord, but the individual contribution of each of these populations to the regional innervation of the spinal cord remains controversial. We have used an adeno‐associated viral (AAV) vector encoding green fluorescent protein under an artificial dopamine beta‐hydroxylase (PRSx8) promoter, to trace the spinal projections from the A5, A6, and A7 groups. Projections from all three groups travel through the spinal cord in both the lateral and ventral funiculi and in the dorsal surface of the dorsal horn, but A6 axons take predominantly the dorsal and ventral routes whereas A5 and A7 axons take a predominantly lateral route. The A6 group provides the denses... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506776 Fri, 16 Dec 2011 05:00:00 +0100 5506776 http://www.medworm.com/index.php?rid=5506786&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23034 AbstractWe studied the histogenesis of the lizard visual system (E30‐adulthood) using a selection of immunohistochemical markers, which proved relevant in other vertebrates. By E30, the Pax6+ pseudostratified retinal epithelium shows few newborn retinal ganglion cells (RGCs) in the centro‐dorsal region expressing neuron‐ and synaptic‐specific markers as beta‐III tubulin (Tuj1), synaptic vesicle protein‐2 (SV2) and vesicular glutamate transporter‐1 (VGLUT1). Concurrently, pioneer RGC axons run among the Pax2+ astroglia in the optic nerve and reach the superficial optic tectum. Between E30‐E35, the optic chiasm and optic tract remain acellular, but the latter contains radial processes with subpial endfeet expressing vimentin (Vim). From E35, neuron‐ and synaptic‐specific ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506786 Thu, 15 Dec 2011 05:00:00 +0100 5506786 http://www.medworm.com/index.php?rid=5506785&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23033 Abstractß1‐containing integrins are required for persistent synaptic potentiation in hippocampus and regulate hippocampal‐dependent learning. Based largely on indirect evidence, there is a prevailing assumption that ß1‐integrins are localized at synapses, where they contribute to synapse adhesion and signaling, but this has not been examined directly. Here, we investigate the fine localization of ß1‐integrin in adult mouse hippocampus using high‐resolution immunogold labeling, with a particular emphasis on synaptic labeling patterns. We find that ß1‐integrins localize to synapses in CA1 and are concentrated postsynaptically. At the postsynaptic membrane, ß1‐integrins are found more commonly clustered near active zone centers rather than at the peripheral edges. In mice h... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506785 Thu, 15 Dec 2011 05:00:00 +0100 5506785 http://www.medworm.com/index.php?rid=5506784&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23032 AbstractKisspeptin is essential for reproductive functions in human. As a model for the human we have used the female guinea pig, which has a long ovulatory cycle similar to primates. Initially, we cloned a guinea pig kisspeptin cDNA sequence and subsequently explored the distribution and 17β‐estradiol (E2) regulation of kisspeptin mRNA (Kiss1) and protein (kisspeptin) using in situ hybridization, real‐time PCR and immunocytochemistry. In ovariectomized females, Kiss1 neurons were scattered throughout the preoptic periventricular areas (PV), but the vast majority of Kiss1 neurons were localized in the arcuate nucleus (Arc). An E2‐treatment that first inhibits (negative feedback) and then augments (positive feedback) serum luteinizing hormone (LH), increased Kiss1 mRNA density and nu... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506784 Thu, 15 Dec 2011 05:00:00 +0100 5506784 http://www.medworm.com/index.php?rid=5506783&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23031 AbstractCortical and subcortical inputs to the striatum are functionally highly organized and they obey to some extent striatal patch‐matrix topography. Whether this organization is reflected in the density of various glutamatergic endings, is unknown. We, therefore, mapped boutons expressing the vesicular glutamate transporters, VGluT1 and VGluT2, together with boutons immunoreactive for vesicular GABA transporter (VGAT) in patch and matrix throughout the striatum. We used triple‐immunofluorescence staining followed by multichannel, high‐magnification confocal laser scanning and 3D object recognition. Densities of VGluT1‐ and VGluT2 boutons were on average higher in matrix than in patches in all striatal sectors. The dorsal one‐third of the striatum contained the highest densiti... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506783 Thu, 15 Dec 2011 05:00:00 +0100 5506783 http://www.medworm.com/index.php?rid=5506782&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23030 AbstractChondrosteans represent an ancient lineage in ray‐finned bony fishes and hence in jawed vertebrates. This immunohistochemical study in the brain of the Siberian sturgeon reports the neuronal distribution of three cytosolic calcium‐binding proteins: calbindin‐D28k (CB), calretinin (CR) and parvalbumin (PV). CB and CR are widely expressed in different neuron subsets distributed throughout the sturgeon brain. Studies using double immunofluorescence reveal a wide co‐distribution of CB and CR in the brain nuclei but scarce colocalization at cellular level. In the forebrain, CR‐ and CB‐immunoreactive (ir) populations were observed in the olfactory bulbs, pallial and subpallial telencephalic areas and in some diencephalic nuclei. CR‐ir cells were also observed in the posteri... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506782 Thu, 15 Dec 2011 05:00:00 +0100 5506782 http://www.medworm.com/index.php?rid=5506781&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23029 AbstractSPARC‐like 1 (SC1) is a member of the SPARC family of matricellular proteins that has been implicated in the regulation of processes such as cell migration, proliferation and differentiation. Here we show that SC1 exhibits remarkably diverse and dynamic expression in the developing and adult nervous system. During development, SC1 localizes to radial glia and pial‐derived structures, including the vasculature, choroid plexus and pial membranes. SC1 is not down‐regulated in postnatal development, but its expression shifts to distinct time windows in subtypes of glia and neurons, including astrocytes, large projection neurons, Bergmann glia, Schwann cells and ganglionic satellite cells. In addition, SC1 expression levels and patterns are not altered in the SPARC null mouse, sug... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506781 Thu, 15 Dec 2011 05:00:00 +0100 5506781 http://www.medworm.com/index.php?rid=5506780&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23028 AbstractThe terminal Schwann cells that accompany lanceolate sensory endings in the rat vibrissal follicle are known to display the small plasma membrane invaginations caveolae that concentrate Ca2+ signaling molecules. We have previously shown the cells to generate Ca2+ signals at the lamellar processes covering the receptor axons through activation of the metabotropic purinoceptor P2Y2. To investigate the roles for caveolae in the spatiotemporal organization of Ca2+ signals, terminal Schwann cells were observed by immunohistochemistry for the caveola protein caveolin‐1, and by transmission and scanning electron microscopy. In addition, immunohistochemical detection of P2Y2 and its coupling partner Gq/11 along with a confocal image analysis of the purinergically‐induced glial Ca2+ res... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506780 Thu, 15 Dec 2011 05:00:00 +0100 5506780 http://www.medworm.com/index.php?rid=5506779&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23027 AbstractIndividual types of retinal neurons are distributed to minimize proximity to neighboring cells. Many of these same cell types extend dendrites to provide coverage of the retinal surface. These two cardinal features of retinal mosaics are disrupted, for certain cell types, in mice deficient for the Down syndrome cell adhesion molecule, Dscam, exhibiting an aberrant clustering of somata and fasciculation of dendrites. The Dscam‐mutant mouse retina also exhibits excess numbers of these same cell types. The present study compared these two features in Dscam‐mutant retinas with the Bax‐knockout retina, in which excess numbers of two of these cell types, the melanopsin‐positive retinal ganglion cells (MRGCs) and the dopaminergic amacrine cells (DACs), are also present. Whole reti... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506779 Thu, 15 Dec 2011 05:00:00 +0100 5506779 http://www.medworm.com/index.php?rid=5506778&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23026 AbstractWe have examined the development of olfactory neuropils in the hemimetabolous insect Locusta migratoria with an emphasis on the mushroom bodies, protocerebral integration centers implicated in memory formation. Using a marker of the cAMP signaling cascade and lipophilic dye labeling, we obtained new insights into mushroom body organization by resolving previously unrecognized accessory lobelets arising from class III Kenyon cells. We utilized antibodies against axonal guidance cues, such as the cell surface glycoproteins Semaphorin 1a (Sema 1a) and Fasciclin I (Fas I), as embryonic markers to compile a comprehensive atlas of mushroom body development. During embryogenesis, all neuropils of the olfactory pathway transiently expressed Sema 1a. The immunoreactivity was particularly st... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506778 Thu, 15 Dec 2011 05:00:00 +0100 5506778 http://www.medworm.com/index.php?rid=5506777&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23025 AbstractThe superior colliculus (SC) is a key structure within the extrageniculate pathway of visual information to cortex, and is highly involved in visuomotor functions. Previous studies in anthropoid primates have shown that superficial layers of the SC receive direct inputs from various visual cortical areas such as V1, V2, and MT, while deeper layers receive direct inputs from visuomotor cortical areas within the posterior parietal cortex, and the frontal eye fields. Very little is known, however, about the corticotectal projections in prosimian primates. In the current study, we investigated the sources of cortical inputs to the SC in prosimian galagos (Otolemur garnetti) using retrograde anatomical tracers placed into the SC. The superficial layers of the SC in galagos received the ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5506777 Thu, 15 Dec 2011 05:00:00 +0100 5506777 http://www.medworm.com/index.php?rid=5495978&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22755 AbstractBoth vagal and sacral neural crest cells contribute to the enteric nervous system in the hindgut. Because it is difficult to visualize sacral crest cells independently of vagal crest, the nature and extent of the sacral crest contribution to the enteric nervous system are not well established in rodents. To overcome this problem we generated mice in which only the fluorescent protein‐labeled sacral crest are present in the terminal colon. We found that sacral crest cells were associated with extrinsic nerve fibers. We investigated the source, time of appearance, and characteristics of the extrinsic nerve fibers found in the aganglionic colon. We observed that the pelvic ganglion neurons contributed a number of extrinsic fibers that travel within the hindgut between circular and l... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5495978 Tue, 13 Dec 2011 14:05:44 +0100 5495978 http://www.medworm.com/index.php?rid=5495977&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22753 AbstractIdentification of two markers of neurons in the pre‐Bötzinger complex (pre‐BötC), the neurokinin 1 receptor (NK1R) and somatostatin (Sst) peptide, has been of great utility in understanding the essential role of the pre‐BötC in breathing. Recently, the transcription factor dbx1 was identified as a critical, but transient, determinant of glutamatergic pre‐BötC neurons. Here, to identify additional markers, we constructed and screened a single‐cell subtractive cDNA library from pre‐BötC inspiratory neurons. We identified the glycoprotein reelin as a potentially useful marker, because it is expressed in distinct populations of pre‐BötC and inspiratory bulbospinal ventral respiratory group (ibsVRG) neurons. Reelin ibsVRG neurons were larger (27.1 ± 3.8 μm in diame... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5495977 Tue, 13 Dec 2011 14:05:43 +0100 5495977 http://www.medworm.com/index.php?rid=5495976&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22751 AbstractThe adenosine A2A receptor (A2AR) is a potential drug target for the treatment of Parkinson's disease and other neurological disorders. In rodents, the therapeutic efficacy of A2AR modulation is improved by concomitant modulation of the metabotropic glutamate receptor 5 (mGluR5). To elucidate the anatomical substrate(s) through which these therapeutic benefits could be mediated, pre‐embedding electron microscopy immunohistochemistry was used to conduct a detailed, quantitative ultrastructural analysis of A2AR localization in the primate basal ganglia and to assess the degree of A2AR/mGluR5 colocalization in the striatum. A2AR immunoreactivity was found at the highest levels in the striatum and external globus pallidus (GPe). However, the monkey, but not the rat, substantia nigra ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5495976 Tue, 13 Dec 2011 14:05:41 +0100 5495976 http://www.medworm.com/index.php?rid=5495975&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22705 AbstractThe regenerating gene/regenerating islet‐derived (Reg) family is a group of small secretory proteins. Within this family, Reg type‐III (Reg‐III) consists of: Reg‐IIIα, ‐β, ‐γ, and ‐δ. To elucidate the physiological relevance of Reg‐III, we examined the localization and ontogeny of Reg‐IIIβ and Reg‐IIIγ in mice at different time points spanning from embryonic day 13.5 to 7 weeks old, using in situ hybridization and immunohistochemistry. Our results showed that Reg‐IIIβ was expressed in specific subsets of primary sensory neurons and motor neurons, and that expression was transient during the embryonic and perinatal periods. Reg‐IIIβ expression was also observed in absorptive epithelial cells of the intestine. In contrast, Reg‐IIIγ expression was ma... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5495975 Tue, 13 Dec 2011 14:05:36 +0100 5495975 http://www.medworm.com/index.php?rid=5495974&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23022 AbstractFluorescence microscope image of double immunhistochemistry for the detection of tyrosine hydroxylase (green) and the transcription factor Nkx2.1 (red) in a transverse section through the hypothalamus of the turtle, Pseudemys scripta. The catecholaminergic neurons in the suprachiasmatic nucleus are revealed by its content in tyrosine hydroxylase, whereas Nkx2.1 labels the ventricular and subventricular zones of this hypothalamic region. The Journal of Comparative Neurology, Volume 520, Number 3, pages 453–478. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5495974 Tue, 13 Dec 2011 14:05:33 +0100 5495974 http://www.medworm.com/index.php?rid=5459568&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23016 AbstractVisually guided behaviors require the brain to extract features of the visual world and to integrate them in a context‐specific manner. Hymenopteran insects have been prime models for ethological research into visual behaviors for decades but knowledge about the underlying central processing is very limited. This is particularly the case for sky‐compass navigation. To learn more about central processing of visual information in general and specifically to reveal a possible polarization vision pathway in the bee brain, we used tracer injections to investigate the pathways through the anterior optic tubercle, a prominent output target of the insect optic lobe, in the bumblebee Bombus ignitus. The anterior optic tubercle of the bumblebee is a small neuropil of 200 μm width and is... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5459568 Thu, 01 Dec 2011 14:16:31 +0100 5459568 http://www.medworm.com/index.php?rid=5459564&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23020 AbstractDNA methylation is an epigenetic regulatory mechanism commonly associated with transcriptional silencing. DNA methyltransferases (DNMTs) are a family of distantly related proteins that both catalyze the de novo formation of 5‐methylcytosine and maintain these methylation marks in cell‐specific patterns in virtually all mitotic cells of the body. In the adult brain, methylation occurs in progenitor cells of the neurogenic zones and in post‐mitotic neurons. Of the DNMTs, DNMT1 and DNMT3a are most highly expressed in post‐mitotic neurons. While it has been commonly thought all post‐mitotic neurons and glia express DNMTs at comparable levels, the co‐expression of selected DNMTs with markers of distinct neurotransmitter phenotypes has not been previously examined in detail i... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5459564 Thu, 01 Dec 2011 14:14:50 +0100 5459564 http://www.medworm.com/index.php?rid=5459567&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23017 AbstractPrincipal neurons that are partially denervated after brain injury remodel their synaptic connections and show biphasic changes in their dendritic spine density: during an early phase after denervation spine density decreases and during a late phase spine density recovers again. It has been hypothesized that these changes in spine density are caused by a period of increased spine loss followed by a period of increased spine formation. We have tested this hypothesis, which is based on data from fixed tissues, by using time‐lapse imaging of denervated dentate granule cells in organotypic entorhino‐hippocampal slice cultures of Thy1‐GFP mice. Our data show that non‐denervated granule cells turn over spines spontaneously while keeping their spine density constant. Denervation i... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5459567 Thu, 01 Dec 2011 05:00:00 +0100 5459567 http://www.medworm.com/index.php?rid=5459566&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23018 AbstractNeural tracing studies have revealed that the rat medial and lateral septum are targeted by ascending projections from the nucleus incertus, a population of tegmental GABA neurons. These neurons express the relaxin‐family peptide, relaxin‐3; and pharmacological modulation of relaxin‐3 receptors in medial septum alters hippocampal theta rhythm and spatial memory. In an effort to better understand the basis of these interactions, we have characterized the distribution of relaxin‐3 fibers/terminals in relation to different septal neuron populations identified using established protein markers. Dense relaxin‐3 fiber plexuses were observed in regions of medial septum containing hippocampal‐projecting choline acetyltransferase (ChAT)‐, neuronal nitric oxide synthase (nNOS)�... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5459566 Thu, 01 Dec 2011 05:00:00 +0100 5459566 http://www.medworm.com/index.php?rid=5459565&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23019 AbstractKv7 (KCNQ) potassium channel openers (enhancers) decrease neuropathic pain in experimental models. Here we show that C‐fibers, and their associated small diameter neurons in the dorsal root ganglia (both IB4‐ and TrkA‐positive), express Kv7.5. In contrast, C‐fibers did not express detectable levels of Kv7.2 or Kv7.3, which are instead localized to nodes of Ranvier and the cell bodies of large sensory neurons. These data suggest that Kv7.5 provides the primary M current in nociceptive neurons. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5459565 Thu, 01 Dec 2011 05:00:00 +0100 5459565 http://www.medworm.com/index.php?rid=5450331&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22729 This study focused on NOS expressed in the nervous system of the prosobranch neogastropod Stramonita haemastoma. In this study we report compelling evidence on the expression of a constitutive Ca2+/CaM‐dependent neuronal NOS in the central and peripheral nervous system. The prevailing neuronal localization of NADPHd activity was demonstrated by NADPHd histochemistry in both central and peripheral nervous system structures. L‐arginine/citrulline assays suggested that Stramonita NOS is a constitutive enzyme which is both cytosolic and membrane‐bound. Molecular cloning of the full‐length Stramonita NOS (Sh‐NOS) by reverse‐transcription polymerase chain reaction (RT‐PCR) followed by 5′ and 3′ RACE showed that Sh‐NOS is a protein of 1,517 amino acids, containing a PDZ domain... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5450331 Mon, 28 Nov 2011 13:52:31 +0100 5450331 http://www.medworm.com/index.php?rid=5450330&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22694 AbstractMajor common features have been reported for the organization of the basal telencephalon in amniotes, and most characteristics were thought to be acquired in the transition from anamniotes to amniotes. However, gene expression, neurochemical, and hodological data obtained for the basal ganglia and septal and amygdaloid complexes in amphibians (anamniotic tetrapods) have strengthened the idea of a conserved organization in tetrapods. A poorly characterized region in the forebrain of amniotes has been the bed nucleus of the stria terminalis (BST), but numerous recent investigations have characterized it as a member of the extended amygdala. Our study analyzes the main features of the BST in anuran amphibians to establish putative homologies with amniotes. Gene expression patterns dur... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5450330 Mon, 28 Nov 2011 13:52:30 +0100 5450330 http://www.medworm.com/index.php?rid=5450329&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22690 AbstractThe hormones leptin and ghrelin act in apposition to one another in the regulation of body weight homeostasis. Interestingly, both leptin receptor expression and ghrelin receptor expression have been observed within many of the same nuclei of the central nervous system (CNS), suggesting that these hormones may act on a common population of neurons to produce changes in food intake and energy expenditure. In the present study we explored the extent of this putative direct leptin and ghrelin interaction in the CNS and addressed the question of whether a loss of ghrelin signaling would affect sensitivity to leptin. Using histological mapping of leptin receptor and ghrelin receptor expression, we found that cells containing both leptin receptors and ghrelin receptors are mainly located... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5450329 Mon, 28 Nov 2011 13:52:27 +0100 5450329 http://www.medworm.com/index.php?rid=5450328&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22796 (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5450328 Mon, 28 Nov 2011 13:52:22 +0100 5450328 http://www.medworm.com/index.php?rid=5450327&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23016 AbstractAnatomical features of leg motoneurons, dorsal unpaired median (DUM) cells, and sensory neurons in stick insect mesothoracic ganglia were examined using fluorescent dye backfills of lateral nerves. Structures were analyzed in whole‐mounts of ganglia and transverse sections. Numbers of motoneurons and details of their structure by far exceed previously published data. The general neuroanatomical layout of motoneurons matches the general orthopteran pattern. Cell bodies of excitatory motoneurons form clusters in the lateral cortex, dendrites branch mainly in the dorsal neuropil. We identified nine DUM cells, six of which have axons in nerve nl5. Most sensory fibers terminate in the ventral association center (VAC). Twenty‐three small cell bodies located close to the soma of the f... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5450327 Mon, 28 Nov 2011 13:52:21 +0100 5450327 http://www.medworm.com/index.php?rid=5443009&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23003 AbstractMotoneurons are key points of convergence within motor networks, acting as the ‘output channels’ that directly control sets of muscles to maintain posture and generate movement. Here we use genetic mosaic techniques to reveal the origins and architecture of the leg motoneurons of Drosophila. We show that a small number of leg motoneurons are born in the embryo but most are generated during larval life. These postembryonic leg motoneurons are produced by 5 neuroblasts per hemineuromere, and each lineage generates stereotyped lineage‐specific projection patterns. Two of these postembryonic neuroblasts generate solely motoneurons that are the bulk of the leg motoneurons. Within the largest lineage, lineage 15, we see distinct birth‐order differences in projection patterns. A c... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443009 Fri, 25 Nov 2011 13:40:21 +0100 5443009 http://www.medworm.com/index.php?rid=5478031&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23015 In this study, we examined whether the subset of glomeruli targeted by TRPM5 expressing OSNs are innervated by the population of mitral cells that project to the MeA. We injected the retrograde tracer cholera toxin B (CTB) into the MeA of mice in which the TRPM5 promoter drives green fluorescent protein (GFP). We found overlapping clusters of CTB‐labeled mitral cell dendritic branches (CTB (+)) in TRPM5‐GFP positive (TRPM5‐GFP (+)) glomeruli at significantly greater frequency than expected by chance. Despite the significant degree of co‐localization, some amygdalopetal mitral cells extended dendrites to non‐TRPM5‐GFP glomeruli and vice versa, suggesting that although significant overlapping glomerular innervation is observed between these two features, it is not absolute. J. Co... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5478031 Fri, 25 Nov 2011 05:00:00 +0100 5478031 http://www.medworm.com/index.php?rid=5443021&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23015 In this study, we examined whether the subset of glomeruli targeted by TRPM5 expressing OSNs are innervated by the population of mitral cells that project to the MeA. We injected the retrograde tracer cholera toxin B (CTB) into the MeA of mice in which the TRPM5 promoter drives green fluorescent protein (GFP). We found overlapping clusters of CTB‐labeled mitral cell dendritic branches (CTB (+)) in TRPM5‐GFP positive (TRPM5‐GFP (+)) glomeruli at significantly greater frequency than expected by chance. Despite the significant degree of co‐localization, some amygdalopetal mitral cells extended dendrites to non‐TRPM5‐GFP glomeruli and vice versa, suggesting that although significant overlapping glomerular innervation is observed between these two features, it is not absolute. J. Co... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443021 Fri, 25 Nov 2011 05:00:00 +0100 5443021 http://www.medworm.com/index.php?rid=5443020&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23014 AbstractThe mammalian pulvinar complex is a collection of dorsal thalamic nuclei which have been related to several visual and integrative processes. Previous studies have shown that the superficial layers of the superior colliculus project to multiple divisions of the pulvinar complex. While most of these works agree about the existence of an ipsilateral tecto‐pulvinar projection arising from the stratum griseum superficialis, some others report a bilateral projection originating from this same tectal layer. We investigated the organization of the tecto‐pulvinar projections in the Californian ground squirrel using Cholera Toxin B (CTb). We confirmed previous studies showing that the caudal pulvinar of the squirrel receives a massive bilateral projection originating from a specific cel... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443020 Fri, 25 Nov 2011 05:00:00 +0100 5443020 http://www.medworm.com/index.php?rid=5443019&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23013 AbstractWe used tract tracing to reveal the connections of the auditory brainstem in the Tokay gecko (Gekko gecko). The auditory nerve has two divisions, a ventro‐rostrally directed projection of mid‐ to high best frequency fibers to the Nucleus Angularis (NA), and a more dorsal and caudal projection of low to mid‐best frequency fibers that bifurcated to project to both NA and the nucleus magnocellularis (NM). The projection to NM formed large somatic terminals and bouton terminals. NM projected bilaterally to the second order Nucleus Laminaris (NL), such that the ipsilateral projection innervated the dorsal NL neuropil, while the contralateral projection crossed the midline and innervated the ventral dendrites of NL neurons. Neurons in NL were generally bitufted, with dorsoventrally... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443019 Fri, 25 Nov 2011 05:00:00 +0100 5443019 http://www.medworm.com/index.php?rid=5443018&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23012 AbstractThe electronic linking of neuroscience information, including data embedded in the primary literature, would permit powerful queries and analyses driven by structured databases. This task would be facilitated by automated procedures which can identify biological concepts in journals. Here we apply an approach for automatically mapping formal identifiers of neuroanatomical regions to text found in journal abstracts, and apply it to a large body of abstracts from the Journal of Comparative Neurology (JCN). The analyses yield over one hundred thousand brain region mentions which we map to 8,225 brain region concepts in multiple organisms. Based on the analysis of a manually annotated corpus, we estimate mentions are mapped at 95% precision and 63% recall. Our results provide insights ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443018 Fri, 25 Nov 2011 05:00:00 +0100 5443018 http://www.medworm.com/index.php?rid=5443017&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23011 We report that axotomy of giant RS neurons induces a select subset of them to accumulate high levels of synuclein, a synaptic vesicle‐associated protein whose abnormal accumulation is linked to Parkinson's disease. Injury‐induced synuclein accumulation occurred only in neurons that were classified as poor survivors by both histological and Fluoro‐Jade® C staining. In contrast, post‐injury synuclein immunofluorescence remained at control levels in neurons that were identified as good survivors. Synuclein accumulation appeared in the form of aggregated intracellular inclusions. Cells that accumulated synuclein also exhibited more ubiquitin‐containing inclusions, similar to what occurs during disease states. When synuclein levels and cell vitality were measured in the same neurons,... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443017 Fri, 25 Nov 2011 05:00:00 +0100 5443017 http://www.medworm.com/index.php?rid=5443016&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23010 AbstractFeline SMA is a fully penetrant, autosomal recessive lower motor neuron disease in domestic cats that clinically resembles human SMA Type III. A whole genome linkage scan identified a ∼140 kilobase deletion that abrogates expression of LIX1, a novel SMA candidate gene of unknown function. To characterize the progression of feline SMA, we assessed pathological changes in muscle and spinal cord from 3 days of age to beyond onset of clinical signs. EMG analysis indicating denervation occurred between 10 and 12 weeks, with the first neurological signs occurring at the same time. CMAP amplitudes were significantly reduced in the soleus and extensor carpi radialis muscles at 8 to 11 weeks. Quadriceps femoris muscle fibers from affected cats appeared smaller at 10 weeks; by 12 weeks atr... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443016 Fri, 25 Nov 2011 05:00:00 +0100 5443016 http://www.medworm.com/index.php?rid=5443015&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23009 AbstractPerineuronal nets (PNNs) are pericellular coats of condensed matrix which enwrap the cell bodies and dendrites of many adult central nervous system (CNS) neurons. These extracellular matrices (ECM) play a structural role as well as instructive roles for the control of CNS plasticity and the termination of critical periods. The cartilage link protein Crtl1/Hapln1 was reported to be a trigger for the formation of PNNs in the visual cortex. Bral2/Hapln4 is another link protein that is expressed in PNNs, mainly in the brain stem and cerebellum. To assess the role of Bral2 in PNN formation, we examined the expression of PNN components in targeted mouse mutants lacking Bral2. We show here that Bral2‐deficient mice have attenuated PNNs, but the overall levels of chondroitin sulfate prot... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443015 Fri, 25 Nov 2011 05:00:00 +0100 5443015 http://www.medworm.com/index.php?rid=5443014&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23008 AbstractGuiding axonal projections to ipsilateral and contralateral regions is essential for integration of bilateral sensory information and coordination of movement. In the development of olivocerebellar projections, newborn neurons of inferior olivary (IO) nuclei ventrally migrate from the hindbrain rhombic lip to the floor plate (FP). The cell bodies of IO neurons cannot cross the FP but their axons can, and thus IO neurons project their axons only to the contralateral cerebellar cortex. The molecular mechanisms determining the contralateral axonal projections of IO neurons, however, are obscure. The IO neurons and their axons expressed EphA4, whereas the FP expressed an EphA4 ligand, EphrinB3 from embryonic day 12.5. Therefore, we tested whether EphA4‐deficient mice (EphA4−/−) w... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443014 Fri, 25 Nov 2011 05:00:00 +0100 5443014 http://www.medworm.com/index.php?rid=5443013&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23007 In this study, we employed single sensillum staining techniques and investigated the topographic projection patterns of individual ORNs to elucidate the relationship between sensillum types and glomerular organization in the AL. Axons of almost all ORNs projected to individual glomeruli. Axons of ORNs in perforated basiconic sensilla selectively innervated the antero‐dorsal T1‐T4 glomeruli, whereas those in trichoid and grooved basiconic sensilla innervated the postero‐ventral T5‐T9 glomeruli. About 90 % of stained ORNs in trichoid sensilla sent axons to the T5 glomeruli, and more than 90 % of ORNs in grooved basiconic sensilla innervated the T6, T8 and T9 glomeruli. The T5 and T9 glomeruli exclusively receive sensory inputs from the trichoid and grooved basiconic sensilla, respect... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443013 Fri, 25 Nov 2011 05:00:00 +0100 5443013 http://www.medworm.com/index.php?rid=5443012&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23006 AbstractThe subgranular layers (layers 5 and 6) of primary sensory cortex provide corticofugal output to thalamus, and they also project to the appropriate secondary sensory cortices. Here we injected two combinations of different color retrograde fluorescent markers in the thalamic and cortical targets of these layers from the three primary sensory cortices (somatosensory, auditory and visual) in mice to examine the degree of overlap between corticothalamic and interareal corticocortical cells in the subgranular layers. We found that, for all three primary sensory cortices, double‐labeled cells were extremely rare, indicating that corticothalamic and interareal corticocortical cells in the subgranular layers represent largely independent populations. J. Comp. Neurol., 2011. © 2011 Wile... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443012 Fri, 25 Nov 2011 05:00:00 +0100 5443012 http://www.medworm.com/index.php?rid=5443011&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23005 This study examined the distribution of γ‐aminobutyric acid (GABA)B receptors on immunohistochemically‐identified neurons, and levels of GABAB(1) and GABAB(2) mRNA, in the L4 and L5 dorsal root ganglia (DRG) of the rat in theabsence of injury and two weeks after L5 spinal nerve ligation. In uninjured DRG, GABAB(1) immunoreactivity colocalized exclusively with the neuronal marker NeuN and did not colocalize with the satellite cell marker S‐100. The GABAB(1) subunit colocalized to >97% of DRG neurons immunoreactive (IR) for neurofilament 200 (N52) or calcitonin gene‐related peptide (CGRP), or labeled by isolectin B4 (IB4). Immunoreactivity for GABAB(2) was not detectable. L5 spinal nerve ligation did not alter the number of GABAB(1)‐IR neurons or its colocalization pattern in t... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443011 Fri, 25 Nov 2011 05:00:00 +0100 5443011 http://www.medworm.com/index.php?rid=5443010&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23004 AbstractThymosin β4 (Tβ4) is a highly conserved G‐actin binding polypeptide with multiple intra‐ and extracellular functions. While stem‐cell activation as well as promotion of cell‐survival and migration by Tβ4 have been investigated in various in vitro and in vivo studies, there are only few data on implications of Tβ4 in brain development.In the present study, we analysed Tβ4 expression in the developing optic tectum of the chicken (Gallus domesticus) and performed in ovo retroviral transduction and plasmid electroporation for overexpression and knockdown of Tβ4. We found marked Tβ4 expression in the tectal plate and in all neuronal layers of later developmental stages, but not in the ventricular zone where neural stem cells reside and divide. Knockdown of Tβ4 inhibited ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443010 Fri, 25 Nov 2011 05:00:00 +0100 5443010 http://www.medworm.com/index.php?rid=5443022&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22795 AbstractWe analyzed the function of neural progenitors in the developing central nervous system of Xenopus laevis tadpoles by using in vivo time‐lapse confocal microscopy to collect images through the tectum at intervals of 2–24 hours over 3 days. Neural progenitor cells were labeled with fluorescent protein reporters based on expression of endogenous Sox2 transcription factor. With this construct, we identified Sox2‐expressing cells as radial glia and as a component of the progenitor pool of cells in the developing tectum that gives rise to neurons and other radial glia. Lineage analysis of individual radial glia and their progeny demonstrated that less than 10% of radial glia undergo symmetric divisions resulting in two radial glia, whereas the majority of radial glia divide asymme... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5443022 Wed, 23 Nov 2011 05:00:00 +0100 5443022 http://www.medworm.com/index.php?rid=5432877&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22810 AbstractZebrin II (aldolase C) is expressed in a subset Purkinje cells in the mammalian and avian cerebella such that there is a characteristic parasagittal organization of zebrin immunopositive stripes alternating with zebrin immunonegative stripes. Zebrin is not only expressed in the soma and dendrites of Purkinje cells, but also in their axonal terminals. Here, we describe the distribution of zebrin immunoreactivity in both the vestibular and cerebellar nuclei of pigeons (Columbia livia) and hummingbirds (Calypte anna, Selasphorus rufus). In the medial cerebellar nucleus, zebrin positive labelling was particularly heavy in the “shell”, whereas the “core” was zebrin negative. In the lateral cerebellar nucleus, labelling was not as heavy, but a positive shell, negative core was al... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5432877 Tue, 22 Nov 2011 13:37:11 +0100 5432877 http://www.medworm.com/index.php?rid=5423746&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22797 AbstractMedial olivocochlear (MOC) neurons originate in the superior olivary complex and project to the cochlea, where they act to reduce the effects of noise masking and protect the cochlea from damage. MOC neurons respond to sound via a reflex pathway, however, in this pathway the cochlear nucleus cell type that provides input to MOC neurons is not known. We investigated whether multipolar cells of the ventral cochlear nucleus have projections to MOC neurons, by labeling them with injections into the dorsal cochlear nucleus. The projections of one type of labeled multipolar cell, planar neurons, were traced into the ventral nucleus of the trapezoid body, where they were observed terminating on MOC neurons (labeled in some cases by a second cochlear injection of Fluorogold). These termina... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423746 Sat, 19 Nov 2011 13:53:48 +0100 5423746 http://www.medworm.com/index.php?rid=5423762&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23001 AbstractAnts, eusocial insects, have highly elaborate chemical communication systems using a wide variety of pheromones. In the carpenter ant, Camponotus japonicus, workers and queens equip the female‐specific basiconic sensilla on antennae. The antennal lobe, the primary processing center, in female carpenter ants contains about 480 glomeruli which are divided into seven groups (T1‐T7 glomeruli) based on sensory afferent tracts. The axons of sensory neurons in basiconic sensilla are thought to project into female‐specific T6‐glomeruli. Therefore, these sensilla and glomeruli are thought to relate to female‐specific social tasks in the ants. Using dye‐filling into local neurons (LNs) and projection neurons (PNs) in the antennal lobe, we neuroanatomically revealed the existence ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423762 Fri, 18 Nov 2011 05:00:00 +0100 5423762 http://www.medworm.com/index.php?rid=5423761&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23000 AbstractThe development of topographic maps of the sensory periphery is sensitive to the disruption of adenylate cyclase 1 (AC1) signaling. AC1 catalyzes the production of cAMP in a Ca2+/calmodulin dependent manner, and AC1 mutant mice (AC1‐/‐) have disordered visual and somatotopic maps. However, the broad expression of AC1 in the brain and the promiscuous nature of cAMP signaling have frustrated attempts to determine the underlying mechanism for AC1‐dependent map development. In the mammalian visual system, the initial coarse targeting of retinal ganglion cell (RGC) projections to the superior colliculus (SC) and lateral geniculate nucleus (LGN) is guided by molecular cues, while the subsequent refinement of these crude projections occurs via an activity‐dependent process that de... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423761 Fri, 18 Nov 2011 05:00:00 +0100 5423761 http://www.medworm.com/index.php?rid=5423760&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22812 We examined abdominal vagal afferents (n = 33) and the distributions of their intraganglionic laminar endings (IGLEs) in the duodenum. Rats (male, Sprague‐Dawley) received a partial subdiaphragmatic vagotomy that spared a single branch. Wheat germ agglutinin‐horseradish peroxidase (0.5∼1.0 μl) was injected into the nodose ganglion ipsilateral to the vagotomized side. We observed that: the hepatic branch does not project to the stomach, the accessory celiac and celiac branches course along the celiac artery and innervate the intestines, and the left nodose afferents predominantly innervate the duodenum. The hepatic branch innervates the duodenum via the “hepato‐duodenal” sub‐branch and has the densest IGLE distribution in both the dorso‐ventral and rostro‐caudal extension... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423760 Fri, 18 Nov 2011 05:00:00 +0100 5423760 http://www.medworm.com/index.php?rid=5423759&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22811 AbstractMorphine, codeine, morphine‐6‐glucuronide and morphine‐3‐glucuronide are de novo synthesized in mammalian cells and in the central nervous system. Knowledge about endogenous morphine‐like compound distribution in the adult mouse brain has been recently improved, and new hypotheses have been suggested about their potential implications in brain physiology. Endogenous morphine‐like compounds have been shown to be synthesized in the spinal cord, but their localization is unknown. In the present study, we describe the distribution of endogenous morphine‐like compounds (morphine and/or its glucuronides and/or codeine) in the adult mouse spinal cord using a well validated antibody. Using different microscopy approaches, we found the presence of morphine, codeine, and/or mor... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423759 Fri, 18 Nov 2011 05:00:00 +0100 5423759 http://www.medworm.com/index.php?rid=5423758&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22809 AbstractThe effects of age on cerebral capillaries have been examined in area 46 of the prefrontal cortices of sixteen rhesus monkeys, ranging in age from 5 to 35 years. Fourteen of the monkeys had been behaviorally tested prior to their brains being prepared for electronmicroscopic examination. It was found that while the thickness of the outer basal lamina adjacent to the glial limiting membrane increased with age and showed increasing numbers of splits, the inner basal lamina between endothelial cells and pericytes did not become thicker with age, and did not show splitting. There were also no age‐related changes in the extent of the coverage of endothelial cells by pericytes and no change in the frequency of mitochondria in endothelial cells. The factors that did change with age, nam... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423758 Fri, 18 Nov 2011 05:00:00 +0100 5423758 http://www.medworm.com/index.php?rid=5423757&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22808 AbstractProtocadherins constitute the largest subfamily of cadherin genes and are widely expressed in the nervous system. In the present study, we cloned 8 members of the delta‐protocadherin subfamily of cadherins (Pcdh1, Pcdh7, Pcdh8, Pcdh9, Pcdh10, Pcdh17, Pcdh18, and Pcdh19) from the chicken, and investigated their expression in the developing chicken spinal cord by in situ hybridization. Our results showed that each of the investigated delta‐protocadherins exhibits a spatially restricted and temporally regulated pattern of expression. Pcdh1, Pcdh8, Pcdh18 and Pcdh19 are expressed in restricted dorsoventral domains of the neuroepithelial layer at early developmental stages (E2.5‐E4). In the differentiating mantle layer, specific expression profiles are observed for all 8 delta‐p... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423757 Fri, 18 Nov 2011 05:00:00 +0100 5423757 http://www.medworm.com/index.php?rid=5423756&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22807 AbstractTopographic maps are salient features of neuronal organization in sensory systems. Inhibitory components of neuronal circuitry are often embedded within this organization making them difficult to isolate experimentally. The auditory system provides opportunities to study the topographic organization of inhibitory long‐range projection nuclei, such as the superior olivary nucleus (SON). We analyzed the topographic organization of response features of neurons in SON of chickens. Quantitative methods were developed to assess and communicate this organization. These analyses led to three main conclusions: (1) sound frequency is linearly arranged from dorsal (low frequencies) to ventral (high frequencies) in SON; (2) this tonotopic organization is less precise than the organization of... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423756 Fri, 18 Nov 2011 05:00:00 +0100 5423756 http://www.medworm.com/index.php?rid=5423755&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22806 AbstractThe sodium‐driven chloride/bicarbonate exchanger (NDCBE), a member of the SLC4 family of bicarbonate transporters, was recently found to modulate excitatory neurotransmission in hippocampus. Using light and electron microscopic immunohistochemistry, we here demonstrate that NDCBE is expressed throughout the adult rat brain, and selectively concentrates in presynaptic terminals, where it is closely associated with synaptic vesicles. NDCBE is in most glutamatergic axon terminals, and is also present in the terminals of parvalbumin‐positive GABAergic cells. These findings suggest that NDCBE can regulate glutamatergic transmission throughout the brain, and point to a role for NDCBE as a possible regulator of GABAergic neurotransmission. J. Comp. Neurol., 2011. © 2011 Wiley‐Liss,... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423755 Fri, 18 Nov 2011 05:00:00 +0100 5423755 http://www.medworm.com/index.php?rid=5423754&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22805 AbstractThe auditory sector of the thalamic reticular nucleus (TRN) plays a pivotal role in gain and/or gate control of auditory input relayed from the thalamus to cortex. The TRN is also likely involved in cross‐modal sensory processing for attentional gating function. In the present study, we anatomically examined how cortical and thalamic afferents intersect in the auditory TRN with regard to these two functional pathways. Iontophoretic injections of biocytin into subregions of the auditory TRN, which were made with guidance of electrophysiological recording of auditory response, resulted in retrograde labeling of cortical and thalamic cells, indicating the sources of afferents to the TRN. Cortical afferents from area Te1 (temporal cortex, area 1), which contains the primary and anter... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423754 Fri, 18 Nov 2011 05:00:00 +0100 5423754 http://www.medworm.com/index.php?rid=5423753&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22804 This study examines the connectivity in the neural networks controlling respiration in lampreys, a basal vertebrate. Previous studies have shown that the lamprey paratrigeminal respiratory group (pTRG) plays a crucial role in the generation of respiration. Using a combination of anatomical and physiological techniques, we characterized the bilateral connections between the pTRGs and descending projections to the motoneurons. Tracers were injected in the respiratory motoneuron pools to identify pre‐motor respiratory interneurons. Retrogradely labelled cell bodies were found in the pTRG on both sides. Whole‐cell recordings of the retrogradely labelled pTRG neurons showed rhythmical excitatory currents in tune with respiratory motoneuron activity. This confirmed that they were related to ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423753 Fri, 18 Nov 2011 05:00:00 +0100 5423753 http://www.medworm.com/index.php?rid=5423752&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22803 AbstractThe A13 dopaminergic nucleus belongs to the incerto‐hypothalamic area. It is thought to exert autonomous roles by integrating sensory input to autonomic, neuroendocrine and motor output. Although its early development has been well characterized, the factors that contribute to later steps of its formation remain unknown. Transcription factors of the Onecut family have been detected in the A13 nucleus, raising the question of possible roles of these factors during A13 development. Using a combination of immunofluorescence analyzes on sections and after whole‐mount labeling followed by 3D‐reconstructions, we further characterized the second phase of development of the A13 nucleus in the mouse, we described the distribution of the Onecut proteins throughout A13 development and w... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423752 Fri, 18 Nov 2011 05:00:00 +0100 5423752 http://www.medworm.com/index.php?rid=5423751&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22802 AbstractRetinitis Pigmentosa (RP), is a family of inherited diseases causing progressive photoreceptor death,. Retinal ganglion cells (RGCs) form the biological substrate for various therapeutic approaches designed to restore vision in RP individuals. Assessment of survival and preservation of RGCs in animal paradigms mimicking the human disease is of key importance for appropriate implementation of vision repair strategies. Here, we study the survival of RGCs in the rd1 mutant mouse, a known model of early onset, autosomic recessive RP, at various stages of photoreceptor degeneration. Furthermore, we analyze the morphology of various types of RGCs using the newly generated transgenic mouse rd1/Thy1‐GFP, in which the rd1 mutation is associated to GFP expression in a small population of d... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423751 Fri, 18 Nov 2011 05:00:00 +0100 5423751 http://www.medworm.com/index.php?rid=5423750&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22801 AbstractThe type II classic cadherin subfamily contains a number of extensively studied genes (cdh6, cdh8, cdh11); however, the expression and function of the other members, have only been partially described. Here, we employ RT‐PCR and in situ hybridization to characterize cortical and hippocampal expression of all type II cadherins (with the exception of the non‐neural Cdh5) in the developing and adult mouse brain. Many of these genes have ubiquitous mRNA distribution patterns throughout development indicating high functional redundancy, which might be necessary for safe production of the strictly laminated structure of these regions. A few of the genes examined however, exhibit a unique spatio‐temporal pattern of expression, particularly during cortical development indicating a po... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423750 Fri, 18 Nov 2011 05:00:00 +0100 5423750 http://www.medworm.com/index.php?rid=5423749&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22800 In this study, retinas were collected at post‐natal (P) days P5 – 30, 90, 180, and P600. We then immunostained the retinas to examine the morphology and distribution of cones, and to quantify the total cone numbers. Our results indicate that cones undergo extensive changes in their spatial distribution to give rise to a mosaic comprising an orderly array of rings. These rings first begin to appear at P15 at random regions of the retina and become ubiquitous throughout the entire tissue by P90. Such distribution pattern loses its clarity by P180 and mostly disappears at P600, at which time the cones are almost all dead. In contrast, the numbers of cones in RP and normal conditions do not show significant differences at stages as late as P180. Therefore, rings do not form by cell death a... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423749 Fri, 18 Nov 2011 05:00:00 +0100 5423749 http://www.medworm.com/index.php?rid=5423748&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22799 AbstractNew neurons are added into the mammalian olfactory bulb throughout life, but it remains unknown whether the properties of new neurons generated in newborn animals differ from those added during adulthood. We compared the densities of glutamatergic synapses of granule cells (GCs) generated in newborn and adult rats over extended periods of time. We observed that whereas adult‐born GCs maintained stable cell‐to‐cell variability of synaptic densities soon after they integrated into the circuit, cell‐to‐cell variability of synaptic densities of neonatal‐born GCs increased months after their integration. We also investigated whether the synaptic reorganization induced by sensory deprivation occurred differently in mature neonatal‐ and adult‐born GCs. Sensory deprivation ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423748 Fri, 18 Nov 2011 05:00:00 +0100 5423748 http://www.medworm.com/index.php?rid=5423747&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22798 AbstractThe lateral line system of larval zebrafish is emerging as a model to study a range of topics in neurobiology, from hair cell regeneration to sensory processing. However, despite numerous studies detailing the patterning and development of lateral line neuromasts, little is known about the organization of their connections to afferent neurons and targets in the hindbrain. We found that as fish grow and neuromasts proliferate over the body surface, the number of afferent neurons increases linearly. The number of afferents innervating certain neuromasts increases over time, while it decreases for other neuromasts. The ratio of afferent neurons to neuromasts differs between the anterior and posterior lateral line system, suggesting potential differences in sensitivity threshold or spa... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5423747 Fri, 18 Nov 2011 05:00:00 +0100 5423747 http://www.medworm.com/index.php?rid=5410477&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22723 In this study, we demonstrate three populations of preprogalanin mRNA (PPG)‐expressing neurons in the VLM of the adult, male Sprague‐Dawley rat: a retrotrapezoid nucleus (RTN) group, a group in the rostral ventral respiratory group (rVRG), and a subpopulation of A1 neurons. PPG+ neurons express tyrosine hydroxylase (TH) only in the A1 region of the VLM, where approximately 56% of PPG+ neurons contain TH (79 ± 14; n = 4). PPG+ neurons do not express vesicular acetylcholine transporter (vAChT) in the VLM (n = 3). However, 33% of PPG+ neurons contain neurokinin‐1 receptor (NK1R) in the rVRG (126 ± 12; n = 12), accounting for ∼28% of all NK1R+ neurons in the region. Retrogradely transported cholera toxin B injected into the thoracic spinal cord (T1) revealed that bulbospinal PPG+ neu... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5410477 Thu, 17 Nov 2011 04:32:03 +0100 5410477 http://www.medworm.com/index.php?rid=5410476&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22692 AbstractModulation of phosphorylation states of ion channels is a critical step in the development of hyperalgesia during inflammation. Modulatory enhancement of channel activity may increase neuronal excitability and affect downstream targets such as gene transcription. The specificity required for such regulation of ion channels quickly occurs via targeting of protein kinases and phosphatases by the scaffolding A‐kinase anchoring protein 79/150 (AKAP79/150). AKAP79/150 has been implicated in inflammatory pain by targeting protein kinase A (PKA) and protein kinase C (PKC) to the transient receptor potential vanilloid 1 (TRPV1) channel in peripheral sensory neurons, thus lowering threshold for activation of the channel by multiple inflammatory reagents. However, the expression pattern of... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5410476 Thu, 17 Nov 2011 04:31:57 +0100 5410476 http://www.medworm.com/index.php?rid=5410475&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22782 (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5410475 Thu, 17 Nov 2011 04:31:52 +0100 5410475 http://www.medworm.com/index.php?rid=5410474&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.23002 AbstractA composite confocal photomicrograph showing the organization an topographic relations of specific neuronal populations in the hypothalamic paraventricular nucleus (PVH) of a C57BL/6malemouse. One population of PVH neurons (presumptive neuroendocrine) was identified by immunocytochemical detection of the retrograde tracer Fluorogold (FG; green) following its injection in to the tail vein; a second population of PVH neurons (presumptive preautonomic) was back‐labeled following upper thoracic level spinal cord injection of the retrograde tracer Fast Blue (FB; blue). Subsequently, distinct populations of oxytocin (OXY; red)‐ and vasopressin (VAS; magenta)‐ expressing neurons were identified immunocytochemically. At this PVH level neurons labeled only with FG (green) include nume... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5410474 Thu, 17 Nov 2011 04:31:51 +0100 5410474 http://www.medworm.com/index.php?rid=5338170&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22793 In this study we used immunohistochemistry for adenylyl cyclase III (ACIII), a marker of primary cilia, and electron microscope ultrastructural analysis to describe the development and maturation of cilia in mouse neocortical neurons. Our results indicate that ciliogenesis initiates in late fetal stages after neuroblast migration, when the mother centriole docks with the plasma membrane, becomes a basal body and grows a cilia bud we called a procilium. This procilium consists of a membranous protrusion extending from the basal body but lacking axonemal structure, and remains undifferentiated until development of the axoneme and cilia elongation starts around postnatal day 4. Neuronal cilia elongation and final cilia length depends on layer position and is a process that extends for a long ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338170 Sun, 23 Oct 2011 02:26:25 +0100 5338170 http://www.medworm.com/index.php?rid=5338180&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22783 This study indicates that Mel1a and Mel1b melatonin receptors are expressed specifically in the Xenopus OPL to modulate transmission from cones to horizontal cells and OFF bipolar cells, respectively; they are second‐order neurons that predominantly contact ribbon synapses and display OFF responses to light. When combined with results from recent physiological studies, the current results suggests a conserved function for melatonin in enhancing transmission from rods to second‐order neurons across species, although the precise mechanisms by which melatonin enhances this transmission are likely to vary in a species‐dependent manner. J. Comp. Neurol., 2011. © 2011 Wiley‐Liss, Inc. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338180 Thu, 20 Oct 2011 04:00:00 +0100 5338180 http://www.medworm.com/index.php?rid=5338179&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22784 AbstractSea snakes have evolved numerous anatomical, physiological and behavioural adaptations to suit their wholly aquatic lifestyle. However, although sea snakes use vision for foraging and mate selection, little is known about their visual abilities. We used microspectrophotometry, light microscopy and scanning electron microscopy to characterise the retinal photoreceptors of spine‐bellied (Lapemis curtus) and horned (Acalyptophis peronii) sea snakes. Both species have three types of visual pigment sensitive to short‐ (SWS; wavelength of maximum absorbance, λmax 428–430 nm), medium‐ (MWS; λmax 496 nm) and long‐wavelengths of light (LWS; λmax 555–559 nm) in each of three different subtypes of cone‐like single photoreceptor. They also possess a cone‐like double photorec... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338179 Thu, 20 Oct 2011 04:00:00 +0100 5338179 http://www.medworm.com/index.php?rid=5338178&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22785 AbstractMyoinhibitory peptides (MIPs) are a family of insect W(X6)Wamides with inhibitory effects on visceral muscles and juvenile hormone synthesis. Although MIPs are widely distributed within the nervous system, a detailed analysis of their distribution and function in insect brains is still missing. We analyzed the distribution of MIPs in the brain of the cockroach Leucophaea maderae. We focused on the accessory medulla (AMe), a small neuropil near the medulla that acts as the master circadian clock. MALDI‐TOF and Nano‐LC ESI mass spectrometry revealed five Lem‐MIPs in preparations of the AMe and corpora cardiaca. The complete sequences of two of these peptides were identified. Immunocytochemistry revealed wide distribution of MIP‐related peptides in the cockroach brain. The sup... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338178 Thu, 20 Oct 2011 04:00:00 +0100 5338178 http://www.medworm.com/index.php?rid=5338177&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22786 AbstractNucleus laminaris (NL) neurons in the avian auditory brainstem are coincidence detectors necessary for the computation of interaural time differences used in sound localization. In addition to their excitatory inputs from nucleus magnocellularis, NL neurons receive inhibitory inputs from the superior olivary nucleus (SON) that greatly improve coincidence detection in mature animals. The mechanisms that establish mature distributions of inhibitory inputs to NL are not known. We used the vesicular GABA transporter (VGAT) as a marker for inhibitory presynaptic terminals to study the development of inhibitory inputs to NL between embryonic day 9 (E9) and E17. VGAT immunofluorescent puncta were first seen sparsely in NL at E9. The density of VGAT puncta increased with development, first... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338177 Thu, 20 Oct 2011 04:00:00 +0100 5338177 http://www.medworm.com/index.php?rid=5338176&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22787 AbstractThe mesopontine rostromedial tegmental nucleus (RMTg) is a mostly GABAergic structure believed to be a node for signaling aversive events to dopamine (DA) neurons in the ventral tegmental area (VTA). The RMTg receives glutamatergic inputs from the lateral habenula (LHb) and sends substantial GABAergic projections to the VTA, which also receives direct projections from the LHb. To further specify the topography of LHb projections to the RMTg and VTA, small focal injections of the anterograde tracer Phaseolus vulgaris leucoagglutinin were aimed at different subdivisions of the LHb. The subnuclear origin of LHb inputs to the VTA and RMTg was then confirmed by injections of the retrograde tracer cholera toxin subunit b into the VTA or RMTg. Furthermore, we compared the topographic posi... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338176 Thu, 20 Oct 2011 04:00:00 +0100 5338176 http://www.medworm.com/index.php?rid=5338175&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22788 AbstractCalmodulin‐regulated spectrin‐associated protein 1 (Camsap1) has been recognized as a new marker for astrocytic lineage cells and expressed on mature astrocytes in the adult brain (Yamamoto et al., J Neurosci Res. 87:503‐513, 2009). In the present study, we have found that newly born Camsap1‐expressing cells exhibited regional heterogeneity in early phase after stab injury of the mouse brain. In the surrounding area of the lesion site, Camsap1 was expressed on quiescent astrocytes. At 3 days after injury, Camsap1 immunoreactivity was up‐regulated on glial fibrillary acidic protein‐immunoreactive (GFAP‐ir) astrocytes. Some of these astrocytes incorporated bromodeoxyuridine (BrdU) together with re‐expression of the embryonic cytoskeleton protein nestin. In the neighbo... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338175 Thu, 20 Oct 2011 04:00:00 +0100 5338175 http://www.medworm.com/index.php?rid=5338174&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22789 AbstractIn the lateral hypothalamus, groups of functionally related cells tend to be widely scattered rather than confined to discrete, anatomically distinct units. However, using parvalbumin (PV)‐specific antibodies, a solitary, compact cord of PV‐immunoreactive cells (the PV1‐nucleus) has been identified in the ventrolateral tuberal hypothalamus in various species. Here we describe the topography, the chemo‐, cyto‐ and myeloarchitectonics as well as the ultrastructure of this PV1‐nucleus in rodents. The PV1‐nucleus is located within the ventrolateral division of the medial forebrain bundle. In the horizontal plane, it has a length of 1 mm in mice and 2 mm in rats. PV‐immunoreactive perikarya fall into two distinct size categories and number ∼800 in rats and ∼400 in mi... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338174 Thu, 20 Oct 2011 04:00:00 +0100 5338174 http://www.medworm.com/index.php?rid=5338173&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22790 AbstractFor many years, aging was thought to be accompanied by significant decreases in total neuron number across multiple brain regions. However, this view was revised with the advent of modern quantification methods, and it is now widely accepted that the hippocampus and many regions of the cortex show substantially preserved numbers of neurons during normal aging. Nonetheless, age‐related changes in neuron number do occur in focal regions of the primate prefrontal cortex (PFC), but the question of whether age‐related neuron loss is an exclusive characteristic of the PFC in primates remains relatively unexplored. To investigate the loss of neurons with normal aging in rodents, we used unbiased stereological methods to quantify the number of principal neurons and interneurons in the ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338173 Thu, 20 Oct 2011 04:00:00 +0100 5338173 http://www.medworm.com/index.php?rid=5338172&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22791 AbstractPeripheral sensory axons innervate the epidermis early in embryogenesis to detect touch stimuli. To characterize the time course of cutaneous innervation and the nature of interactions between sensory axons and skin cells at early developmental stages, we conducted a detailed analysis of cutaneous innervation in the head, trunk and tail of zebrafish embryos and larvae from 18 to 78 hours post‐fertilization. This analysis combined live imaging of fish expressing transgenes that highlight sensory neurons and skin cells, transmission electron microscopy (TEM), and serial scanning electron microscopy (sSEM). In zebrafish, the skin initially consists of two epithelial layers and all of the axons in the first wave of innervation are free endings. Maturation of the epithelium coincides ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338172 Thu, 20 Oct 2011 04:00:00 +0100 5338172 http://www.medworm.com/index.php?rid=5338171&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22792 AbstractPrevious anatomical and physiological studies have established major glutamatergic and GABAergic neuronal subtypes within the piriform cortical circuits. However, quantitative information regarding axo‐axonic inhibitory synapses mediated by chandelier cells across major cortical subdivisions of piriform cortex is unknown. Therefore, we examined the properties of these synapses across the entire piriform cortex. Our results show: 1) γ–aminobutyric acid membrane transporter 1‐positive varicosities, whose appearance resembles chandelier cartridges, are found around the initial segments of axons of glutamatergic cells across layers II and III. 2) Both the density of axo‐axonic cartridges and the degree of γ–aminobutyric acid membrane transporter 1 innervation in each axo‐... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5338171 Thu, 20 Oct 2011 04:00:00 +0100 5338171 http://www.medworm.com/index.php?rid=5325396&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22781 (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5325396 Tue, 18 Oct 2011 23:25:07 +0100 5325396 http://www.medworm.com/index.php?rid=5325395&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22780 (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5325395 Tue, 18 Oct 2011 23:25:06 +0100 5325395 http://www.medworm.com/index.php?rid=5325394&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22777 (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5325394 Tue, 18 Oct 2011 23:25:04 +0100 5325394 http://www.medworm.com/index.php?rid=5325393&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22688 AbstractSecretoneurin, a 33–34 amino acid neuropeptide derived from the proteolytic processing of the secretogranin‐II precursor protein, is reasonably well conserved in evolution. Goldfish secretoneurin shares >75% similarity overall with other vertebrate secretoneurin sequences. The secretoneurin peptide has numerous functions that include neuroinflammation, neurotransmitter release, and neuroendocrine regulation. A detailed description of the central distribution of secretoneurin immunoreactivity is only known for the rat. Using our polyclonal antibody against the central, conserved core of the secretoneurin peptide we studied the distribution of secretoneurin‐like immunoreactivity in the goldfish brain. Secretoneurin immunoreactivity was found in the olfactory bulb, entopedunc... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5325393 Tue, 18 Oct 2011 23:25:00 +0100 5325393 http://www.medworm.com/index.php?rid=5325392&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22794 AbstractDetailed analysis of the synaptic inputs to the primate DB1 bipolar cell has been precluded by the absence of a suitable immunohistochemical marker. Here we demonstrate that antibodies for the EF‐hand calcium‐binding protein, secretagogin, strongly label the DB1 bipolar cell as well as a mixed population of GABAergic amacrine cells in the macaque retina. Using secretagogin as a marker, we show that the DB1 bipolar makes synaptic contact with both L/M as well as S‐cone photoreceptors and only minimal contact with rod photoreceptors. Electron microscopy showed that the DB1 bipolar makes flat contacts at both triad‐associated and nontriad‐associated positions on the cone pedicle. Double labeling with various glutamate receptor subunit antibodies failed to conclusively determ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5325392 Tue, 18 Oct 2011 23:24:48 +0100 5325392 http://www.medworm.com/index.php?rid=5325391&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22779 AbstractThe cocaine‐ and amphetamine‐regulated transcript (CART) peptidergic system is involved in processing diverse neuronal functions in adult animals, including energy metabolism. Though widely distributed in the brain of a range of vertebrates, the ontogeny of this system has not been explored. The CART immunoreactive system in the zebrafish CNS was studied across developmental stages till adulthood. The peptide is expressed as early as 24 hours post‐fertilization and establishes itself in several discrete areas of the brain and spinal cord as development progresses. The trends in CART ontogeny suggest that it may be involved in the establishment of commissural tracts, typically expressing early but subsequently decaying. CART elements are commonly overrepresented in diverse sen... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5325391 Tue, 18 Oct 2011 23:23:28 +0100 5325391 http://www.medworm.com/index.php?rid=5262671&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22758 (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5262671 Thu, 29 Sep 2011 14:09:49 +0100 5262671 http://www.medworm.com/index.php?rid=5262670&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22724 AbstractSeveral behavioral and electrophysiological studies indicate that all classes of echinoderms, including Echinoidia, the class to which sea urchins belong, are photosensitive and exhibit complex behavioral responses to light or changes in light intensity. However, no discrete photosensitive structure has been identified in sea urchins. The purpose of this study was to provide new insights into eye evolution by determining whether distinct photosensory structures are present in adult sea urchins. Recently, we showed that the Strongylocentrotus purpuratus genome contains orthologs of many mammalian retinal genes and that these genes are expressed in tube feet, suggesting the presence of photoreceptor neurons. To determine whether this is so, we identified several features of tube feet... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5262670 Thu, 29 Sep 2011 14:09:46 +0100 5262670 http://www.medworm.com/index.php?rid=5262669&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22719 AbstractThe central extended amygdala is the major output center for telencephalic control of ingestion, fear responses, stress, and anxiety. In spite of the abundant data supporting the similarity in neurochemistry, connections, and function along the extended amygdala, embryological support for this continuum is lacking. By using a combination of in vitro migration assays, in situ hybridization, and immunostaining, here we show that its major components, including central amygdala and lateral bed nucleus of the stria terminalis (BST), are mosaics formed by different proportions of dorsal lateral ganglionic eminence (LGE)‐, ventral LGE‐, and medial ganglionic eminence (MGE)‐derived principal neurons. The dorsal LGE produces Pax6‐expressing neurons that primarily populate lateral p... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5262669 Thu, 29 Sep 2011 14:09:43 +0100 5262669 http://www.medworm.com/index.php?rid=5262668&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22718 AbstractPreviously, we compared molecular profiles of one population of wild‐type (WT) mouse facial motoneurons (FMNs) surviving with FMNs undergoing significant cell death after axotomy. Regardless of their ultimate fate, injured FMNs respond with a vigorous pro‐survival/regenerative molecular response. In contrast, the neuropil surrounding the two different injured FMN populations contained distinct molecular differences that support a causative role for glial and/or immune‐derived molecules in directing contrasting responses of the same cell types to the same injury. In the current investigation, we utilized the facial nerve axotomy model and a presymptomatic amyotrophic lateral sclerosis (ALS) mouse (SOD1) model to experimentally mimic the axonal die‐back process observed in AL... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5262668 Thu, 29 Sep 2011 14:09:41 +0100 5262668 http://www.medworm.com/index.php?rid=5262667&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22713 AbstractWhereas the “vertical” elements of the insect olfactory pathway, the olfactory receptor neurons and the projection neurons, have been studied in great detail, local interneurons providing “horizontal” connections in the antennal lobe were ignored for a long time. Recent studies in adult Drosophila demonstrate diverse roles for these neurons in the integration of odor information, consistent with the identification of a large variety of anatomical and neurochemical subtypes. Here we focus on the larval olfactory circuit of Drosophila, which is much reduced in terms of cell numbers. We show that the horizontal connectivity in the larval antennal lobe differs largely from its adult counterpart. Only one of the five anatomical types of neurons we describe is restricted to the a... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5262667 Thu, 29 Sep 2011 14:09:37 +0100 5262667 http://www.medworm.com/index.php?rid=5262666&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22680 AbstractPrevious reports have described inputs to the somatosensory cortex (S1) in mouse or rat using retrograde or anterograde tracers. Such studies do not, however, reveal which particular cell types within the S1 cortex receive direct monosynaptic connections from these input sources. Here we describe the monosynaptic inputs to a subpopulation of mouse S1 inhibitory neurons that express ErbB4. We used a previously described “bridge protein,” composed of the ErbB4 ligand, neuregulin (NRG1), fused to the avian viral receptor TVB (TVB‐NRG1), along with EnvB pseudotyped lentivirus (LV) and rabies virus (RV), to selectively coinfect ErbB4‐expressing neurons (Choi et al. [2010] Proc Natl Acad Sci U S A 107:16703–16708). The RV had its glycoprotein gene deleted and replaced with mChe... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5262666 Thu, 29 Sep 2011 14:09:36 +0100 5262666 http://www.medworm.com/index.php?rid=5262665&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22778 We examined the anatomy of this neuronal population in the brain of the silkmoth Bombyx mori. Using intracellular dye injection, we labeled a total of 246 PNs and systematically analyzed their morphological features, including the soma position, antennocerebral tract, and number of innervating glomeruli. For example, we analyzed PNs that had somata in the different cell clusters, innervated overlapping but different groups of glomeruli, and ran through different pathways. We also identified glomeruli innervated by PNs using a previously established procedure that first classifies glomeruli into regional groups and then identifies individual glomeruli. We analyzed uniglomerular PNs (75.6% of the total) and found heterogeneity in the dendritic morphology of the PNs that was dependent on the ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5262665 Thu, 29 Sep 2011 14:09:32 +0100 5262665 http://www.medworm.com/index.php?rid=5252116&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22776 AbstractVisually guided behaviors require the brain to extract features of the visual world and to integrate them in a context‐specific manner. Hymenopteran insects have been prime models for ethological research into visual behaviors for decades but knowledge about the underlying central processing is very limited. This is particularly the case for sky‐compass navigation. To learn more about central processing of visual information in general and specifically to reveal a possible polarization vision pathway in the bee brain, we used tracer injections to investigate the pathways through the anterior optic tubercle, a prominent output target of the insect optic lobe, in the bumblebee Bombus ignitus.The anterior optic tubercle of the bumblebee is a small neuropil of 200 μm width and is ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5252116 Mon, 26 Sep 2011 01:29:42 +0100 5252116 http://www.medworm.com/index.php?rid=5240020&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22760 AbstractMany molecules are expressed heterogeneously in subpopulations of cerebellar Purkinje cells (PCs) and inferior olive (IO) neurons during development or in adulthood. These expression patterns are often organized in longitudinal stripes in the cerebellar cortex, which may be related to functional compartmentalization. FoxP2, a transcription factor, is expressed in PCs and IO neurons, but the details of its expression pattern remain unclear. Here we examined FoxP2 expression patterns systematically by immunostaining serial sections of the hindbrain from embryonic day 14.5 to adulthood in mice.FoxP2 was highly expressed in virtually all PCs at and before postnatal day 6 (P6), except for those in the flocculus and small parts of nodulus (vermal lobule X), where FoxP2 expression was mod... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240020 Thu, 22 Sep 2011 14:11:55 +0100 5240020 http://www.medworm.com/index.php?rid=5252118&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22774 AbstractProtein interacting specifically with Tc10, PIST, is a Golgi‐associated sorting protein involved in regulating cell‐surface targeting of plasma membrane receptors. The present study provides the first comprehensive description of PIST distribution in the mammalian central nervous system and of its subcellular localization by immunocytochemistry. PIST is distributed widely throughout the neuraxis, predominantly associated with neuronal cell bodies and dendrites. In hippocampal neurons, in vitro and in situ, PIST displayed a patchy subcellular distribution in an area surrounding the nucleus and extending into one of the major dendrites. By co‐localization with the trans‐Golgi marker TGN38, we were able to show that PIST is associated largely but not exclusively with the trans... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5252118 Thu, 22 Sep 2011 04:00:00 +0100 5252118 http://www.medworm.com/index.php?rid=5252117&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22775 AbstractProlactin stimulates dopamine release from neuroendocrine dopaminergic (NEDA) neurons in the hypothalamic arcuate nucleus (ARC) to maintain low levels of serum prolactin. Elevated prolactin levels during pregnancy and lactation may mediate actions in other hypothalamic regions such as the paraventricular nucleus (PVN) and rostral preoptic area (rPOA). We predicted that NEDA neurons would be more sensitive prolactin targets than neurons in other regions because they are required to regulate basal prolactin secretion. Moreover, differences in the accessibility of the ARC to prolactin in blood may influence the responsiveness of this population. Therefore, we compared prolactin‐induced signaling in different hypothalamic neuronal populations following either systemic or icv prolacti... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5252117 Thu, 22 Sep 2011 04:00:00 +0100 5252117 http://www.medworm.com/index.php?rid=5240033&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22773 AbstractCones are critically dependent on interphotoreceptor retinoid‐binding protein (IRBP) for retinoid delivery in the visual cycle. Cone‐dominant vertebrates offer an opportunity to uncover the molecular basis of IRBP's role in this process. Here, we explore the association of IRBP with the interphotoreceptor matrix (IPM) of cones versus rods in cone dominant retinas from chicken (Gallus domesticus), turkey (Meleagris gallopavo), and pig (Sus scrofa). Retinas were detached and fixed directly, or washed in saline prior to fixation. Disassociated photoreceptors with adherent matrix were also prepared. Under hypotonic buffer, insoluble matrix was delaminated from saline washed retinas. The distribution of IRBP, as well as glycans binding peanut agglutinin (cone matrix), and wheat germ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240033 Tue, 20 Sep 2011 04:00:00 +0100 5240033 http://www.medworm.com/index.php?rid=5240032&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22772 In this study, we found that the temporal expression of NB‐3 in the deep layers of the motor cortex in mice was coincident with the development of the corticospinal tract (CST). Clear NB‐3 immunoreactivity in the CST trajectory strongly suggested that NB‐3 was expressed specifically in projecting CST axons. By tracing CST axons in NB‐3−/− mice at different developmental stages, we found that these axons were capable of projecting and forming a normal trajectory. However, the projection was greatly delayed in NB‐3−/− mice compared to wild‐type (WT) mice from the embryonic to postnatal stages, a period that is coincident with the completion of the CST projection in mice. Subsequently, although their projection was delayed, CST axons in NB‐3−/− mice gradually complet... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240032 Tue, 20 Sep 2011 04:00:00 +0100 5240032 http://www.medworm.com/index.php?rid=5240031&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22771 AbstractInhibitory and excitatory synaptic inputs onto trigeminal motoneurons play an important role in coordinating jaw movements. Previously, we reported that the phenotype of the inhibitory boutons apposing the somata of jaw‐closing (JC) motoneurons changes from GABA‐positive (GABA+) to predominantly glycine‐positive (Gly+) during development. In the present study, we investigated the development of inhibitory and excitatory boutons apposing antagonistic jaw‐opening (JO) motoneurons (anterior digastric motoneurons) at postnatal days 2 (P2), P11, and P31 in the rat. JO motoneurons were retrogradely‐labeled with horseradish peroxidase. Postembedding immunogold staining with antisera against GABA, Gly, and glutamate (Glut) was performed, and followed by quantitative ultrastructur... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240031 Tue, 20 Sep 2011 04:00:00 +0100 5240031 http://www.medworm.com/index.php?rid=5240030&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22770 In conclusion, axonal regeneration in the locust olfactory system appears to be possible, precise, and fast, opening the possibility for future functional and mechanistic studies. J. Comp. Neurol., 2011. © 2011 Wiley‐Liss, Inc. (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240030 Tue, 20 Sep 2011 04:00:00 +0100 5240030 http://www.medworm.com/index.php?rid=5240029&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22769 (Source: The Journal of Comparative Neurology) The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240029 Tue, 20 Sep 2011 04:00:00 +0100 5240029 http://www.medworm.com/index.php?rid=5240028&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22768 AbstractMutations in human LIS1 cause abnormal neuronal migration and a smooth brain phenotype known as lissencephaly. Lis1+/‐ (Pafah1b1) mice show defective lamination in the cerebral cortex and hippocampal formation, while homozygous mutations result in embryonic lethality. Given that Lis1 is highly expressed in embryonic neurons, we hypothesized that sympathetic and parasympathetic preganglionic neurons (SPNs and PPNs) would exhibit migratory defects in Lis1+/‐ mice. The initial radial migration of SPNs and PPNs that occurs together with somatic motor neurons appeared unaffected in Lis1+/‐ mice. The subsequent dorsally‐directed tangential migration, however, was aberrant in a subset of these neurons. At all embryonic ages analyzed, the distribution of SPNs and PPNs in Lis1+/‐ ... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240028 Tue, 20 Sep 2011 04:00:00 +0100 5240028 http://www.medworm.com/index.php?rid=5240027&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22767 We examined this issue using the rodent somatic system as a model. In rat SI, deep somatic inputis processed mainly in the dysgranular zone (DSZ) enclosed by the cutaneous barrel subfields. Using biotinylated dextran amine (BDA) as anterograde tracer, wecharacterized the topography of corticostriatal and corticofugal projections arising inthe DSZ. The DSZ projections terminate mainly in the lateral subregions of the striatum that are also known as the target of certain SI cutaneous areas. This suggests that SI processing of deep and cutaneous information may be integrated, to a certain degree, in this striatal region. By contrast, at both thalamic and pre‐thalamic levels as far asthespinal cord, descending projections from DSZ terminate in areas largely distinguishable from those that re... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240027 Tue, 20 Sep 2011 04:00:00 +0100 5240027 http://www.medworm.com/index.php?rid=5240026&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22766 In this study, we addressed the topographic distribution and amino acid neurotransmitter phenotype of endocannabinoid‐sensitive hypothalamic neurons in mice. The in situ hybridization detection of CB1 mRNA revealed high levels of expression in the medial septum (MS) and the diagonal band of Broca (DBB), moderate levels in the preoptic area and the hypothalamic lateroanterior (LA), paraventricular (Pa), ventromedial (VMH), lateral mammillary (LM) and ventral premammillary (PMV) nuclei, and low levels in many other hypothalamic regions including the suprachiasmatic (SCh) and arcuate (Arc) nuclei. This regional distribution pattern was compared to location of GABAergic and glutamatergic cell groups, as identified by the expression of glutamic acid decarboxylase 65 (GAD65) and type 2 vesicul... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240026 Tue, 20 Sep 2011 04:00:00 +0100 5240026 http://www.medworm.com/index.php?rid=5240025&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22765 AbstractSeveral subtypes of melanopsin‐expressing, intrinsically‐photosensitive retinal ganglion cells (ipRGCs) have been reported. The M1 type of ipRGCs exhibit distinct properties compared with the remaining (non‐M1) cells. They differ not only in their soma size and dendritic arbor, but also in their physiological properties, projection patterns and functions. However, it is not known how these differences arise. We tested the hypothesis that M1 and non‐M1 cells express Brn3 transcription factors differentially. Brn3 family of class IV POU‐domain transcription factors, Brn3a, Brn3b and Brn3c are involved in differentiation, dendritic stratification and axonal projection of retinal ganglion cells during development. Using double immunofluorescence for Brn3 transcription factors... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240025 Tue, 20 Sep 2011 04:00:00 +0100 5240025 http://www.medworm.com/index.php?rid=5240024&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22764 AbstractPresynaptic active zones are essential structures for synaptic vesicle release, but the developmental regulation of their number and maintenance during aging at mammalian neuromuscular junctions (NMJs) remains unknown. Here, we analyzed the distribution of active zones in developing, mature, and aged mouse NMJs by immunohistochemical detection of the active zone‐specific protein Bassoon. Bassoon is a cytosolic scaffolding protein essential for the active zone assembly in ribbon synapses and some brain synapses. Bassoon staining showed a punctate pattern in nerve terminals and axons at the nascent NMJ on embryonic days 16.5–18.5. Three‐dimensional reconstruction of NMJs revealed that the majority of Bassoon puncta within an NMJ were attached to the presynaptic membrane from po... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240024 Tue, 20 Sep 2011 04:00:00 +0100 5240024 http://www.medworm.com/index.php?rid=5240023&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22763 AbstractThe mesopallium is a thick cell plate occupying a substantial portion of the avian dorsal pallium, but its hodology is incompletely known. In pigeons we examined fiber connections of the frontodorsal (MFD) and frontoventral mesopallium (MFV), the ventrolateral mesopallium (MVL), the lateral (MIVl) and medial (MIVm) parts of the intermediate ventral mesopallium, and the caudal mesopallium (MC). MFV, MIVl and MC connect reciprocally with secondary centers of the trigeminal, tectofugal, and auditory systems, respectively. MVL forms reciprocal connections with both the entopallial core and belt. MFV, MIVl, MVL, and MC receive thalamic inputs different from those of primary sensory pallial regions and have reciprocal connections with the caudolateral nidopallium (NCL) or arcopallium. MI... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240023 Tue, 20 Sep 2011 04:00:00 +0100 5240023 http://www.medworm.com/index.php?rid=5240022&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22762 AbstractThe patterns of distribution of a set of conserved brain developmental regulatory transcription factors and neuronal markers were analyzed in the hypothalamus of the juvenile turtle, Pseudemys scripta. Combined immunohistochemical techniques were used for the identification of the main boundaries and subdivisions in the optic, paraventricular, tuberal and mammillary hypothalamic regions. The combination of Tbr1 and Pax6 with Nkx2.1 allowed the identification of the boundary between the telencephalic preoptic area, rich in Nkx2.1 expression, and the prethalamic eminence, rich in Tbr1 expression. In addition, at this level Nkx2.2 expression defined the boundary between the telencephalon and the hypothalamus. The dorsalmost hypothalamic domain was the supraoptoparaventricular region t... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240022 Tue, 20 Sep 2011 04:00:00 +0100 5240022 http://www.medworm.com/index.php?rid=5240021&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22761 This study examined the hypothalamus of 51 rhesus monkeys (23 male,18 female, 6.5 to 31 years old) using design‐based stereology to obtain unbiased estimates of neuron and glia numbers and the Cavalieri method to estimate volumes for 8 reference spaces: total unilateral hypothalamus, suprachiasmatic nucleus (SCN), supraoptic nucleus (SON), paraventricular nucleus (PVN), dorsomedial nucleus (DM), ventromedial nucleus (VM), medial mammillary nucleus (MMN), and lateral hypothalamic area (LHA). The results demonstrated no age‐related difference in neuron number, glia number, or volume in any area in either sex except the PVN of male monkeys, which showed a significant increase in both neuron and glia numbers with age. Comparison of males and females for sexual dimorphisms revealed no signi... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5240021 Tue, 20 Sep 2011 04:00:00 +0100 5240021 http://www.medworm.com/index.php?rid=5228145&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22701 AbstractSensory function of human dental pulp has long been known. A composite role has been suggested for odontoblasts as sensory cells in addition to the synthesis of dentinal matrix. However, the neural basis for such a composite sensory activity remains enigmatic. Here, we aimed to probe the question by pursuing an evolutionary logic; if dental pulp is a vestigial sensory organ co‐opted to a function of synthesis of mineralized matrix, essential elements of neurosensory organs may persist in dental pulp. Through structural analysis by confocal laser scanning microscopy, three distinct cell populations adjacent to odontoblasts, glial fibrillary acidic protein (GFAP)+ seracytes, S100+ telacytes, and HLA‐II+ alacytes were identified in peripheral human dental pulp. Subsequent molecula... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5228145 Mon, 19 Sep 2011 05:01:28 +0100 5228145 http://www.medworm.com/index.php?rid=5228144&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22699 AbstractNerve‐impulse conduction is greatly speeded by myelin sheaths in vertebrates, oligochaete annelids, penaeid and caridean shrimp, and calanoid copepods. In the first three invertebrate cases, myelin arises from glial cells, as it does in vertebrates. The contribution of the glial cells to the layered structure of the myelin is clear: their nuclei are either embedded in the layers or reside in contiguous cytoplasmic compartments, and their cell membranes are seen to be continuous with those of the myelin layers. However, with calanoids, the association with glial cells presumed necessary to generate the myelin has never been satisfactorily identified. We have conducted a systematic examination of thin sections through different parts of the copepod nervous system to identify the st... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5228144 Mon, 19 Sep 2011 05:01:27 +0100 5228144 http://www.medworm.com/index.php?rid=5228143&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22670 This study was performed to provide an account of those connections and to seek a better understanding of how afferents might contribute to the functional interrelatedness of the VTA, SNc, RRF, and PAGvl. Ventral midbrain structures received injections of retrograde tracer, and the resulting retrogradely labeled structures were targeted with injections of anterogradely transported Phaseolus vulgaris leucoagglutinin. Whereas all injections of retrograde tracer into the VTA, SNc, RRF, or PAGvl produced labeling in many structures extending from the cortex to caudal brainstem, pronounced labeling of structures making up the central division of the extended amygdala occurred following injections that involved the RRF and PAGvl. The anterograde tracing supported this finding, and the combinatio... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5228143 Mon, 19 Sep 2011 05:01:19 +0100 5228143 http://www.medworm.com/index.php?rid=5228142&cid=s_33646_25_f&fid=33646&url=http%3A%2F%2Fdx.doi.org%2F10.1002%252Fcne.22759 AbstractThe 15–20 physiological types of retinal ganglion cells (RGCs) can be grouped according to whether they fire to increased illumination in the receptive‐field center (ON cells), decreased illumination (OFF cells), or both (ON‐OFF cells). The diversity of RGCs has been best described in the rabbit retina, which has three types of ON‐OFF RGCs with complex receptive‐field properties: the ON‐OFF direction‐selective ganglion cells (DSGCs), the local edge detectors, and the uniformity detectors. Here we describe a novel type of bistratified ON‐OFF RGC that has not been described in either physiological or morphological studies of rabbit RGCs. These cells stratify in the ON and OFF sublaminae of the inner plexiform layer, branching at about 30% and 60% depth, between the ON... The Journal of Comparative Neurology journals http://www.medworm.com/rss/comments.php?id=5228142 Mon, 19 Sep 2011 05:01:14 +0100 5228142