bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of altered neuronal activity on cell size in the medial nucleus of the trapezoid body and ventral cochlear nucleus of the gerbil
Authors: Pasic Thomas R. , Moore David R. , Rubel Edwin W. 
Published: January 2005

AbstractActivity‐dependent transneuronal regulation of neuronal soma size has been studied in the medial nucleus of the trapezoid body and ventral cochlear nucleus of adolescent gerbils. Cochlear ablation or tetrodotoxin has been used to eliminate afferent electrical activity in auditory nerve fibers permanently or for 24 or 48 hours. Previous studies have shown that the cross‐sectional area of spherical cell somata in the ipsilateral anteroventral cochlear nucleus decreases within 24 hours of electrical activity blockade with tetrodotoxin, which is fully reversible when activity is restored. The present findings extend this work by directly comparing the results of unilateral blockade of auditory nerve action potentials or unilateral cochlear ablation on the size of spherical and globular cell bodies in the ventral cochlear nucleus with changes produced by the same manipulations in third‐order cells, principal neurons in the medial nucleus of the trapezoid body. Soma size in both ventral cochlear nucleus cell types decreases reliably by 24 hours after cochlear removal or eighth nerve activity blockade by tetrodotoxin. Soma size of neurons in the contralateral medial nucleus of the trapezoid body decreases 48 hours, but not 24 hours, after either manipulation. When activity in auditory nerve fibers is allowed to resume for 7 days following a 48‐hour activity blockade, soma size fully recovers in the medial nucleus of the trapezoid body as well as in ventral cochlear nucleus neurons. We also report that the cross‐sectional area of neuronal soma in the medial nucleus of the trapezoid body is larger in lateral regions of medial nucleus of the trapezoid body (low‐frequency representation) than in the medial regions of the nucleus (high‐frequency representation). We conclude that cell body size changes in brainstem auditory neurons are reversible and that the signals associated with the loss and subsequent recovery of soma size are activity related. However, the delayed effect of activity deprivation in the medial nucleus of the trapezoid body suggests that trophic substances released by afferent axons may contribute to the maintenance of anatomical characteristics. © 1994 Wiley‐Liss, Inc.
Connectivity of the lobus parolfactorius of the domestic chicken (Gallus domesticus): An anterograde and retrograde pathway tracing study
Authors: Székely Andrea D. , Boxer Margaret I. , Stewart Michael G. , Csillag András 
Published: January 2005

AbstractIn 1–week‐old domestic chicks, the connectivity of the lobus parolfactorius (LPO), part of the avian basal ganglia, was investigated using Phaseolus vulgaris leucoagglutinin and horseradish peroxidase for anterograde and retrograde pathway tracing, respectively. Tyrosine hydroxylase immunocytochemistry was applied in combination with Phaseolus lectin to assess the overlap between LPO efferents and diencephalic and meseticephalic catecholamine centres. Anterograde projections from LPO were detected in the hyperstriatum, neostriatum, and paleostriatum. Intranuclear connections were also apparent within the LPO. Descending LPO efferents innervated the lateral mammillary and intramedial nuclei and the dorsomedial thalamic complex. Fibres from LPO were observed in the tectal gray, substantia nigra, area ventralis tegmentalis of Tsai, and the adjacent nucleus mesencephalicus profundus. Further caudally, projections from LPO reached the nucleus papillioformis, locus coeruleus, and subcoeruleus ventralis. LPO efferents were coextensive with tyrosine hydroxylase‐positive cells in the nuclei mamillaris lateralis and intramedialis of the hypothalamus, area ventralis tegmentalis, substantia nigra, locus coeruleus, and subcoeruleus ventralis of mesencephalic and pontine tegmentum. Close contacts between LPO fibres and catecholamine cells were visible in the nigra and the area ventralis tegmentalis. Retrograde labelling from LPO was found in the archistriatum, dorsomedial thalamic complex, nuclei lateralis anterior and superficialis parvicellularis thalami, substantia nigra, central gray, area ventralis tegmentalis of Tsai, and locus coeruleus and in cells dorsal to the decussation of brachium conjunctivum. Reciprocal connections were verified between the LPO and the following areas: dorsomedial thalamic complex, central gray, substantia nigra, area ventralis of Tsai, and locus coeruleus. © 1994 Wiley‐Liss, Inc.
GABAergic projection from the basal forebrain to the visual sector of the thalamic reticular nucleus in the cat
Authors: Bickford M. E. , Günlük A. E. , van Horn S. C. , Sherman S. M. 
Published: January 2005

AbstractWe examined the projection from the basal forebrain to thalamic and cortical regions of the visual system in cats, with particular reference to the visual sector of the thalamic reticular nucleus, the lateral geniculate nucleus, and the striate cortex. First, we made injections of wheat germ agglutinin conjugated to horseradish peroxidase (WGA‐HRP) into the visual sector of the thalamic reticular nucleus and found cells labeled by retrograde transport in the lateral nucleus basalis magnocellularis. Injection of biocytin into the basal forebrain resulted in the anterograde labeling of a dense band of fibers and terminals within the entire thalamic reticular nucleus; this labeling extended through the visual sector including the perigeniculate nucleus. No orthograde labeling was found in the lateral geniculate nucleus. Next, we addressed the issue of putative neurotransmitters used by this pathway using a variety of immunocytochemical and histochemical markers. In this fashion, we identified two populations of cells in the nucleus basalis magnocellularis of the cat: large cholinergic cells that contain choline acetyltransferase, NADPH‐diaphorase, and calbindin and that project to striate cortex and smaller cells that contain gamma‐aminobutyric acid (GABA), glutamic acid decarboxylase, and parvalbumin and that project to the visual sector of the thalamic reticular nucleus. We also examined at the electron microscopic level terminals in the visual sector of the thalamic reticular nucleus that were labeled from a biocytin injection in the basal forebrain. Most of these terminals form symmetric contacts onto dendrites and were revealed by postembedding immunocytochemical staining to be positive for GABA. © 1994 Wiley‐Liss, Inc.
Developmental plasticity of reticulospinal and vestibulospinal axons in the north american opossum, Didelphis virginiana
Authors: Wang X. M. , Qin Y. Q. , Xu X. M. , Martin G. F. 
Published: January 2005

AbstractWe have shown previously that rubral axons grow around a lesion of their spinal pathway in the North American opossum if it is made at early stages of development. In the present experiments, we have asked whether reticular and vestibular axons have the same ability. The spinal cord was hemisected at postnatal day 20, 12, or 5, well within the critical period for rubrospinal plasticity, and, approximately 30 days later, bilateral injections of fast blue were made about four segments caudal to the lesion. The pups were killed 4 or 5 days after the injections. In most of the animals lesioned on postnatal day 20, labeled neurons were not found in the medial part of the pontine reticular nucleus or the dorsal part of the lateral vestibular nucleus ipsilateral to the lesion. The spinal projections from both areas are exclusively ipsilateral. When the lesions were made at postnatal day 12 or 5, however, labeled neurons were present in both areas, suggesting that they supported axons that had grown caudal to the lesion. As was expected from previous studies, rubral neurons were labeled contralateral to the lesion in all three groups. In the opossum, as in other species, the red nucleus projects contralaterally. We conclude that reticular and vestibular axons, like axons from the red nucleus, grow around a lesion of their pathway during development and that the critical period for their plasticity ends earlier than that for rubrospinal axons. © 1994 Wiley‐Liss, Inc.
Glial domains and axonal reordering in the chiasmatic region of the developing ferret
Authors: Reese B. E. , Maynard T. M. , Hocking D. R. 
Published: January 2005

AbstractThis study has examined the developing glial architecture of the optic pathway and has related this to the changing organization of the constituent axons. Immunocytochemistry was used to reveal the distribution of glial profiles, and DiI was used to label either radial glial profiles or optic axons. Electron microscopy was used to determine the distribution of glial profiles, axons, growth cones, and wrists at different locations along the pathway.Three different glial boundaries were defined: Two of these are revealed as changes in the distribution of vimentin‐immunoreactive profiles occurring in the prechiasmatic optic nerve and at the threshold of the optic tract, respectively, and one by the presence of glial fibrillary acidic protein (GFAP)‐immunoreactive profiles at the chiasmatic midline. The latter, midline boundary may be related to the segregation of nasal from temporal optic axons. The boundary at the threshold of the optic tract coincides with the segregation of dorsal from ventral optic axons that emerges at this location in the pathway. The segregation of old from young optic axons is shown to occur only gradually along the pathway. Glial profiles are most frequent in the deeper parts of the tract, coursing parallel to the optic axons and orthogonal to their usual radial axis. These are suggested to arise from later‐growing radial glial fibers that are diverted to grow amongst the older optic axons. Those glial profiles may subsequently impede axonal invasion, thus creating the chronotopic reordering by forcing the later‐arriving axons to accumulate superficially. © 1994 Wiley‐Liss, Inc.
Colocalization of prosomatostatin‐derived peptides in the caudate‐putamen of the rat
Authors: Rushlow W. , Naus C. C. G. , Flumerfelt B. A. 
Published: January 2005

AbstractIn the striatum of rat, somatostatin 14, somatostatin 28, and somatostatin 28 (1–12) have previously been localized within a small population of medium aspiny local circuit neurons. Because all three peptide fragments are generated through the cleavage of prosomatostatin by different converting enzymes, the possibility for differential expression of these peptides exists. In order to investigate this possibility, frozen sections were collected from the brains of adult female Wistar rats fixed with 4% paraformaldehyde and double labelled using immunocytochemistry and in situ hybridization. Sections were first processed for somatostatin 14, somatostatin 28, or somatostatin 28(1–12) by using the avidin‐biotin complex immunocytochemical technique followed by in situ hybridization using 35S‐labelled antisense riboprobes to somatostatin mRNA. The results of such analysis revealed that somatostatin 28 and somatostatin mRNA are 100% colocalized. Somatostatin 14 and somatostatin 28(1–12), in contrast, are only present within 66% of the neurons that express somatostatin mRNA. Examination of the anatomical distribution of neurons that express both somatostatin mRNA and somatostatin 14 or somatostatin 28(1–12) protein reveals that these neurons are present throughout the caudate‐putamen of rat but are more prevalent in the ventromedial regions. Neurons that express somatostatin mRNA but not somatostatin 14 or somatostatin 28(1–12) are also present throughout the caudate‐putamen but are most numerous within a dorsolateral strip just beneath the corpus callosum. These results suggest that the somatostatin neuron population within the rat caudate‐putamen is actually composed of two smaller subpopulations based on neuropeptide content. The first subpopulation contains somatostatin 28 and constitutes one‐third of the total somatostatin population, whereas the other contains somatostatin 28, somatostatin 14, and somatostatin 28(1–12) and represents the remaining two‐thirds of the cells that express somatostatin mRNA. © 1994 Wiley‐Liss, Inc.
Ipsi‐ and contralateral commissural growth cones react differently to the cellular environment of the ventral zebrafish spinal cord
Authors: Bernhardt Robert R. 
Published: January 2005

AbstractEarly commissural axons in the zebrafish spinal cord extend along a pathway consisting of a ventrally directed ipsilateral, a contralateral diagonal, and a contralateral longitudinal segment. The midline floor plate cell is one important cue at the transition from the ipsilateral to the contralateral pathway segments. In order to identify additional guidance cues, the interactions between commissural growth cones and their substrates were examined at the electron microscopic level in the different pathway segments. The growth cones extended near the superficial margin of the spinal cord, within filopodial reach of three bilateral longitudinal axon pathways that were ignored irrespective of whether other axons were already present. Ultimately the commissural growth cones pioneered an additional independent longitudinal pathway in the dorsolateral spinal cord. Neuroepithelial cells were extensively contacted in the lateral marginal zone of the dorsal spinal cord and are thus in a position to contribute to the establishment of the longitudinal commissural pathway segment. The extent of contact with neuroepithelial cells in the ventral spinal cord was dependent on whether commissural growth cones had already crossed the ventral midline: ipsilateral, but not contralateral, growth cones showed extensive contacts with neuroepithelial processes and minor contacts with the basal lamina. In marked contrast, commissural growth cones that had already crossed the ventral midline and entered the diagonal pathway segment showed major appositions to the basal lamina. Extensive contact with the basal lamina was first established in the ventral midline region, where crossing growth cones always inserted between the basal lamina and the base of the midline floor plate cells. This indicates that a change occurs in the response characteristics of commissural growth cones as they cross the ventral midline of the spinal cord. Such a change could help to explain why the growth cones extend first toward but then away from the ventral midline. 1994 Wiley‐Liss. Inc.
Immunocytochemical localization of the β2subunit of the gamma‐aminobutyric acidAreceptor in the rat brain
Authors: Moreno Juan I. , Piva Marta A. , Miralles Celia P. , de Blas Angel L. 
Published: January 2005

AbstractAn antiserum to the β2subunit of the rat gamma‐aminobutyric acid (GABAA) receptor was prepared by immunizing a rabbit with a fusion protein expressed in bacteria. The fusion protein had the large, intracellular loop expanding between the putative M3 and M4 transmembrane domains of the β2subunit fused to staphylococcal protein A (SPA). The antiserum immunoprecipitated both the solubilized and the affinity‐purified GABAAreceptors. The anti‐β2antibodies were affinity purified on immobilized β2intracellular loop peptide. The antibodies recognized a 55–57 kDa peptide in immunoblots of either crude membranes from rat cerebral cortex or affinity‐purified GABAAreceptors from bovine cerebral cortex. Immunocytochemistry with the affinity‐purified antibody has revealed for the first time the localization of the β2subunit in the rat brain. A comparative study of the regional and cellular immunoreactivities of the affinity‐purified anti‐β2antibody and the monoclonal antibody 62‐3G1 (which recognizes both β2and β3subunits) is presented. The procedure described for generating and preparing specific anti‐β2subunit antibodies that are valuable for immunocytochemistry could be extended to other GABAAreceptor subunits. © 1994 Wiley‐Liss, Inc.
Two types of interneuron in the dorsal lateral geniculate nucleus of the rat: A combined NADPH diaphorase histochemical and GABA immunocytochemical study
Authors: Gabbott Paul L. A. , Bacon Sarah J. 
Published: January 2005

AbstractThe rationale for this study was to provide a comprehensive light microscopical description of the morphology of diaphorase‐reactive neurons and neuropil elements in the dorsal lateral geniculate nucleus (dLGN) of the rat. An additional objective was to quantitatively assess whether a subpopulation of the diaphorase‐reactive neurons, previously shown to be GABA‐immunoreactive, constitute a distinct type of local‐circuit neuron in the rat dLGN.Diaphorase activity was localised in a population of predominantly bipolar fusiform neurons. These cells were weak to moderately stained and possessed the morphological features of intrinsic inhibitory neurons, previously called class B neurons in the rat dLGN. Quantitative estimates indicated that the diaphorase‐reactive neurons constituted approximately 10% of the total neuron composition of the dLGN. The majority (about 83%) of the diaphorase‐reactive cells were located in the lateral half of the nucleus. In addition, a dense plexus of diaphorase‐reactive varicose fibres was found throughout the dLGN lying between the oriented fibre bundles coursing dorsoventrally through the LGN.Diaphorase‐reactive punctae were found to be closely associated with the somata and proximal dendritic segments of nonreactive neurons and also with the stained proximal dendritic segments of diaphorase‐reactive dLGN neurons. The source of the diaphorasereactive varicose fibres in the dLGN was unknown. Evidence suggests, however, that they are of extrinsic origin.The GABA‐immunoreactive nature of the diaphorase neurons in the dLGN was demonstrated by colocalising GABA immunoreactivity within the somata of diaphorase‐reactive cells. The majority (> 90%) of diaphorase‐reactive dLGN neurons were GABA‐immunopositive. Also present was a distinct population of GABA‐immunopositive neurons that were not diaphorase‐reactive. In this study, cells that were solely GABA‐immunopositive have been called class B1neurons, while cells that were both diaphorase‐reactive and GABA‐immunoreactive have been called class B2neurons. Size‐frequency distributions of somatic profile areas established that the two populations of GABA‐immunoreactive neuron were significantly different. Class B1neurons constituted 57%, with class B2cells representing 43% of all GABA‐immunostained neurons in the rat dLGN.The characteristic morphological features, neurochemical identity and frequency of the diaphorase‐reactive neurons in the rat dLGN indicate that they represent a subpopulation of inhibitory interneurons with the ability to affect intrinsic dLGN operations and thalamocortical interactions using the neuromodulator nitric oxide.
Distribution of β‐endorphin‐like‐immunoreactive structures in the chicken and quail brain as demonstrated with a new homologous antibody directed against a synthetic peptide
Authors: van Gils Jelle , Absil Philippe , Moons Lieve , Grauwels Luc , Vandesande Frans , Balthazart Jacques 
Published: January 2005

AbstractA polyclonal rabbit antibody was raised against a synthetic peptide fragment located at the C‐terminal end of turkey β‐endorphin (β‐END) and used to analyze the distribution of β‐END‐immunoreactive‐like structures in the quail and chicken brain. Three major groups of immunopositive cells were detected in the preoptic area‐hypothalamus complex. A thin layer of immunopositive cells was parallel and adjacent to the ventral edge of the brain in the preoptic and anterior hypothalamic region, a more numerous group of immunoreactive perikarya was located along the walls of third ventricle in these same regions, and, finally, a few scattered cells were found in a more lateral position on both the internal and external sides of the tip of the fasciculus prosencephali lateralis. The periventricular cell population extended in the caudal direction unti the posterior hypothalamus. Labelled fibers were always associated with these immunoreactive perikarya, and they were also found in the adjacent hypothalamic regions. A dense innervation of the median eminence was also detected. These data are compared with previous studies in mammals and birds that had identified more restricted populations of immunoreactive cells and the possible sources of the observed discrepancy are discussed. The functional significance of the present data is also briefly analyzed.
Perirhinal and parahippocampal cortices of the macaque monkey: Cortical afferents
Authors: Suzuki Wendy L. , Amaral David G. 
Published: January 2005

AbstractNeuropsychological studies have recently demonstrated that the macaque monkey perirhinal (areas 35 and 36) and parahippocampal (areas TH and TF) cortices contribute importantly to normal memory function. Unfortunately, neuroanatomical information concerning the cytoarchitectonic organization and extrinsic connectivity of these cortical regions is meager. We investigated the organization of cortical inputs to the macaque monkey perirhinal and parahippocampal cortices by placing discrete injections of the retrograde tracers fast blue, diamidino yellow, and wheat germ agglutinin conjugated to horseradish peroxidase throughout these areas. We found that the macaque monkey perirhinal and parahippocampal cortices receive different complements of cortical inputs. The major cortical inputs to the perirhinal cortex arise from the unimodal visual areas TE and rostral TEO and from area TF of the parahippocampal cortex. The perirhinal cortex also receives projections from the dysgranular and granular subdivisions of the insular cortex and from area 13 of the orbitofrontal cortex. In contrast, area TF of the parahippocampal cortex receives its strongest input from more caudal visual areas V4, TEO, and caudal TE, as well as prominent inputs from polymodal association cortices, including the retrosplenial cortex and the dorsal bank of the superior temporal sulcus. Area TF also receives projections from areas 7a and LIP of the posterior parietal lobe, insular cortex, and areas 46, 13, 45, and 9 of the frontal lobe. As with area TF, area TH receives substantial projections from the retrosplenial cortex as well as moderate projections from the dorsal bank of the superior temporal sulcus; unlike area TF, area TH receives almost no innervation from areas TE and TEO. It does, however, receive relatively strong inputs from auditory association areas TE and TEO. It does, however, receive relatively strong inputs from auditory association areas on the convexity of the superior temporal gyrus. © 1994 Wiley‐Liss, Inc.