bluuebunny/crossref_metadata_2025_split huggingface dataset:
Taurine immunoreactivity in the rat supraoptic nucleus: Prominent localization in glial cells
Authors: Decavel Chantal , Hatton Glenn I. 
Published: January 2005

AbstractTaurine is an inhibitory amino acid that hyperpolarizes magnocellular neurosecretory neurons. To determine which cell types in the rat supraoptic nucleus contain taurine, we used a monoclonal antibody raised against a taurine conjugate. Preembedding immunocytochemistry was carried out at the light and electron microscopic levels using diaminobenzidine and gold‐substituted silver‐intensified peroxidase as markers. We report the presence of taurine in all cellular compartments of the supraoptic nucleus, except axons, with variable labeling intensities among the different compartments. Few cell bodies of magnocellular neurons were immunoreactive, but many distal dendrites and some proximal ones showed weak‐to‐moderate levels of immunoreactivity. Strong immunoreactivity was found over glial cell bodies and their processes, in particular in the ventral glial lamina of the supraoptic nucleus. Large astrocytic processes labeled with the taurine antibody included the endfeet participating in the glial limitans around capillaries and at the ventral surface of the hypothalamus. Other types of immunoreactive astropytic profiles were found scattered within the neuropil where these processes participated in different interactions with the neuronal elements of the supraoptic nucleus. Immunoreactive glial expansions, sometimes even the main process of the glial cell, engulfed axonal boutons. Other labeled glial processes were found between two magnocellular perikarya or closely apposed to the membrane of axonal boutons contacting the neuronal cell bodies. The frequent finding of closely apposed glial and dendritic elements bearing different levels of taurine‐like immunoreactivity suggests that exchange of taurine between those two compartments may occur. We propose that taurine could be released from supraoptic glia by a small decrease in osmolarity or by receptor‐mediated mechanisms during conditions of low hormonal (vasopressin and/or oxytocin) needs. Such released taurine could then act on presynaptic or postsynaptic sites, or both, to exert its neuromodulatory actions. © 1995 Wiley‐Liss, Inc.
Decrease and long‐term recovery of choline acetyltransferase immunoreactivity in adult cat somatosensory cortex after peripheral nerve transections
Authors: Avendaño Carlos , Umbriaco Denis , Dykes Robert W. , Descarries Laurent 
Published: January 2005

AbstractThe functional reorganization of cerebral cortex following peripheral deafferentation is associated with changes in a number of neurotransmitters and related molecules. Acetylcholine (ACh) enhances neuronal responsiveness and could play a role in activity‐dependent cortical plasticity. In this study, choline acetyltransferase (ChAT) immunohistochemistry was used to investigate ACh innervation of the primary somatosensory cortex in cats sustaining complete unilateral forearm and paw denervations. Survival times of 2–52 weeks were examined. The deafferented contralateral cortex was defined electrophysiologically, and quantitative estimates of ChAT‐immunoreactive fiber density were obtained from the forelimb and hindlimb sectors of area 3b in both hemispheres. In the 3b forelimb sector contralateral to the deafferentation, a decrease in density of ChAT‐positive fibers relative to the ipsilateral hemisphere was apparent at 2 weeks and most pronounced at 13 weeks, involving all cortical layers except layer I. There was no such decrease in the hindlimb sector, but the loss of ChAT immunoreactivity extended to sectors representing proximal forelimb and trunk. Changes in ChAT immunoreactivity were no longer found after 1 year of survival. This long‐lasting but reversible lowering of ChAT immunoreactivity could result from a loss of afferent activity in basalis neurons and/or trophic influences retrogradely exerted by cortex on these cells. Reduced ACh transmission might then contribute to the loss of gamma aminobutyric acid (GABA) inhibition in the deafferented cortex by decreasing the activation of inhibitory interneurons. The long‐term recovery of a normal ChAT immunoreactivity in cortex could be a consequence of its functional reorganization. © 1995 Wiley‐Liss, Inc.
Evolution of cortical responsiveness subsequent to multiple forelimb nerve transections: An electrophysiological study in adult cat somatosensory cortex
Authors: Dykes Robert W. , Avendaño Carlos , Leclerc Serge S. 
Published: January 2005

AbstractMultiunit recordings along mediolateral rows in the primary somatosensory cortex of the animals described by C. Avendafio, D. Umbriaco, R. W. Dykes, and L. Descarries (1995, J. Comp. Neurol. 354:321–332) provided information about the functional status of the regions in and near the deafferented cortex. Responses changed along this axis from normally organized receptive fields in the hindlimb representation through a transition zone of unusually small receptive fields into the clearly deafferented forelimb representation, where receptive fields were uncommon and often had unusual characteristics.The most abrupt change along this axis was the appearance of a repetitive, bursting discharge pattern in the multiunit activity near the border of the deprived cortex. The appearance of this pattern was used as a reference to describe differences between normal and deprived cortices. The nature of these differences evolved with time. Much of the deprived cortex lacked identifiable receptive fields for months after the nerve transections and, 1 year later, still only about half of the recording sites within the deprived region displayed organized receptive fields. Some sites within the deprived region lacking definable receptive fields could be excited at long latencies by somatic stimuli anywhere on the body. With time, regions of normal cortex near the border with the deprived zone became more involved in these processes. Spontaneous activity and thresholds also changed with time in both normal and deprived cortices.These electrophysiological responses occurred during a time when choline acetyltransferase staining was reduced in and around the deprived cortex (Avendaño et al., 1995); the effects of nerve transections were most pronounced between the 8th and 13th weeks, as was the reduction in immunostaining; however, although immunostaining had returned to normal levels at 1 year, many parts of the deprived cortex remained without new afferent drive, some being unresponsive to any somatic stimuli. © 1995 Wiley‐Liss, Inc.
AII amacrine cell population in the rabbit retina: Identification by parvalbumin immunoreactivity
Authors: Casini Giovanni , Rickman Dennis W. , Brecha Nicholas C. 
Published: January 2005

AbstractParvalbumin (PV) is a calcium‐binding protein localized to selected neurons in the nervous system, including the retina. This investigation evaluated the distribution of PV immunoreactivity in the rabbit retina using immunohistochemistry with a monoclonal antibody directed to carp PV. In the inner nuclear layer (INL), PV immunoreactivity was present in horizontal and amacrine cells. In the ganglion cell layer, PV immunostaining was confined to somata that are likely to be both displaced amacrine cells and ganglion cells. PV‐immunoreactive (IR) amacrine cells were positioned in the proximal INL adjacent to the inner plexiform layer (IPL). These cells usually gave rise to a single primary process, which arborized into two distinct bands in the IPL. In sublamina a, the processes were thin and had large, irregular endings. In sublamina b, multiple processes branched from the primary process and were characterized by varicosities and spines. PV‐IR amacrine cell bodies measured from 8 to 10 μm in diameter. Their density was highest in the visual streak and lowest in the periphery of the superior retina. The average number of PV‐IR amacrine cells was 464,045 cells per retina (N = 3), and the average regularity index of the PV‐IR cell mosaic was 3.23. PV‐IR amacrine cells were further characterized by double‐label immunofluorescence experiments using antibodies to PV and tyrosine hydroxylase (TH). Varicose TH‐IR processes were in close apposition to many PV‐IR amacrine cells and often formed “ring structures” around them. Together, these morphological, quantitative, and histochemical observations indicate that PV immunoreactivity in the INL is localized predominantly to AII amacrine cells, and therefore it is a valuable marker for the identification of this cell type. © 1995 Wiley‐Liss, Inc.
Expression of trk receptors in the developing and adult human central and peripheral nervous system
Authors: Muragaki Yoshihiro , Timothy Nigel , Leight Susan , Hempstead Barbara L. , Chao Moses V. , Trojanowski John Q. , Lee Virginia M.‐Y. 
Published: January 2005

AbstractA family of tyrosine receptor kinases known collectively as trk receptors plays an essential role in signal transduction mediated by nerve growth factor and related neurotrophins. To localize the major trk receptors (trkA, B and C) in the developing and adult central (CNS) and peripheral (PNS) nervous system, we generated monoclonal antibodies (MAbs) to extracellular (MAbs E7, E13, E16, E21, E29) and intracellular (MAb I2) domains of human trkA fused to glutathione S‐transferase. Several MAbs (E7, E13, E16) recognized glycosylated trkA (gp 140trk and gp110trk) in Western blots, one MAb (E7) recognized non‐glycosylated (p80trk) and glycosylated trkA in immunoprecipitation assays, and two MAbs (E13, E29) detected trkA on the cell surface of NIH3T3 cells transfected with a trkA cDNA. Although generated to trkA fusion proteins, this panel of MAbs also recognized trkB and trkC in flow cytometric studies of NIH3T3 cells transfected with trkB or trkC cDNAs. Thus, we used these pan‐trk MAbs to probe selected regions of the CNS and PNS including the hippocampus, nucleus basalis of Meynert, cerebellum, spinal cord, and dorsal root ganglion (DRG) to localize trkA, B, and C receptors in the developing and adult human nervous system. These studies showed that trk receptors are expressed primarily by neurons and are detectable very early in the developing hippocampus, cerebellum, spinal cord, and DRG. Although the distribution and intensity of trk immunoreactivity changed with the progressive maturation of the CNS and PNS, immunoreactive trk receptors were detected in neurons of the adult human hippocampus, nucleus basalis of Meynert, cerebellum, spinal cord, and DRG. This first study of trk receptor proteins in the developing and adult human CNS and PNS documents the expression of these receptors in subsets of neurons throughout the developing and adult nervous system. Thus, although the expression of trk receptor proteins is developmentally regulated, the constitutive expression of these neurotrophin receptors by neurons in many regions of the adult human CNS and PNS implies that mature trk receptor‐bearing neurons retain the ability to respond to neurotrophins long after terminal neuronal differentiation is complete. © 1995 Wiley‐Liss, Inc.
Substance P‐immunoreactive neurons in the human retina
Authors: Cuenca Nicolás , De Juan Joaquín , Kolb Helga 
Published: January 2005

AbstractSubstance P (SP) is a neuropeptide that acts as a neurotransmitter or a neuromodulator in the retina. The aim of this study was to identify the type(s) and the distribution of the SP‐immunoreactive (SP‐IR) cells in the human retina. We have used an antiserum to SP to immunostain neurons in postmortem human retinae. Immunostained retinae were processedwith the avidin‐biotin complex (ABC) to visualize the cells either whole mounted in glycerol or embedded in plastic. Some retinae were also sectioned at 20 μm in order to obtain radial views of stained cells. SP‐IR amacrine cells stain intensely and appear to be of a single type in the human retina. They are large‐field cells with large cell bodies (16 μm diameter) lying in normal or displaced positions on either side of the inner plexiform layer (IPL). Their sturdy, spiny, and appendage‐bearing dendrites stratify in stratum 3 (S3) of the IPL, where many overlapping, fine dendrites intermingle to form a plexus of stained processes. Either cell bodies or primary dendrites emit an “axon‐like” process that, typically, divides into two long, fine processes, which run in opposite directions for hundreds of micrometers in S5 and S3 before disappearing as distinct entities in the stained plexus in S3. Long, fine dendrites also pass from the dendritic plexus to run in S5 and down to the nerve fiber layer to end as large varicosities at blood vessel walls. In addition, fine processes are emitted from the dendritic plexus that runs in S1, and some pass up to the outer plexiform layer (OPL) to run therein for short distances. The SP‐IR amacrine cell has many similaritiesto the thorny, type 2 amacrine cells described from Golgi studies.In addition to the SP‐IR amacrine cells, a presumed ganglion cell type is faintly immunoreactive. Its 20–22 μpm cell body gives rise to a radiate, sparsely branched, widespreading dendritic tree running in S3. Its dendrites and cell body become enveloped by the more intensely SP‐IR processes and boutons from the SP‐IR amacrine cell type. The SP‐IR ganglion cell type most resembles G21 from a Golgi study. © 1995 Wiley‐Liss, Inc.
Developmental changes in the expression of γ‐aminobutyric acidA/benzodiazepine receptor subunit mRNAs in the inferior olivary complex
Authors: Chang C. C. Anne , Luntz‐Leybman Vera , Evans James E. , Rotter Andrej , Frostholm Adrienne 
Published: January 2005

AbstractThe pharmacological and physiological properties of ligand‐gated ion channels are dependent on their subunit composition; spontaneously occurring changes in subunit composition during neuronal development may result in dramatic functional differences between embryonic and adult forms of the receptor complex. In the present study, in situ hybridization with antisense cRNA probes was used to examine the subunit composition of the γ‐aminobutyric acidA/benzodiazepine (GABAA/BZ) receptor in the developing inferior olivary complex. This receptor is thought to be a pentameric chloride channel comprised of selected α, β, γ, δ, and ρ subunits, the majority of which have several isoforms: α1−6, β1−4, γ1−4 and ρ1, 2. Among the 13 subunit variants present in the mammalian central nervous system, α2−5 β3, and γ1, 2 mRNAs are expressed at significant levels in the inferior olivary complex. Two clearly different temporal patterns of GABAA/BZ receptor subunit mRNA expression were observed: The expression of α3, α5, β3, and γ2 mRNAs was at a peak during embryonic and early postnatal development followed by rapid down‐regulation thereafter. Conversely, α2, α4, and γ1 mRNA expression was very low or absent during early development, and a pronounced increase was observed at the end of postnatal week 1. These studies suggest that there are developmental changes in the subunit composition of the GABAA/BZ receptor in inferior olivary neurons. These changes in subunit expression, which occur during a period of major alterations in afferent and efferent synaptic connections, may subserve a change in the role of GABA from its function as a neurotrophic factor to that of an inhibitory neurotransmitter. © 1995 Wiley‐Liss, Inc.
Colocalization of gephyrin and GABAA‐receptor subunits in the rat retina
Authors: Sassoè‐Pognetto M. , Kirsch J. , Grünert U. , Greferath U. , Fritschy J. M. , Möhler H. , Betz H. , Wässle H. 
Published: January 2005

AbstractGephyrin is a protein that copurifies with the glycine receptor (GlyR) and is required for the clustering of GlyRs at postsynaptic sites. Previously, it was thought that antibody mAb 7a, directed against gephyrin, was a specific marker for GlyR. However, there is evidence that gephyrin can also be found at nonglycinergic synapses. Here, immunocytochemistry was applied to show this directly for the rat retina. Both gephyrin and different Subunits of the γ‐aminobutyric acid (GABA)A receptor were localized to discrete puncta in the inner plexiform layer, and these puncta were shown by electron microscopy to represent synaptic sites. Double immunocytochemistry revealed that GABAA receptors and GlyRs are not colocalized. However, gephyrin and different subunits of GABAA receptors were found to occur at the same synapses. The amount of colocalization varied with the GABAA receptor subunit composition and was most extensive for the α2 subunit, less for the α3 subunit, and minimal for the αl subunit. The gephyrin present at GABAergic synapses of the retina might also be involved with clustering of receptors at the postsynaptic sites. Hence, localization of gephyrin can no longer be considered as a unique marker of glycinergic synapses. © 1995 Wiley‐Liss, Inc.
Expression of the p150Glued component of the dynactin complex in developing and adult rat brain
Authors: Melloni Richard H. , Tokito Mariko K. , Holzbaur Erika L. F. 
Published: January 2005

Abstractp150Glued is a component of the dynactin (Glued) complex that has been shown in vitro to be a required activator of cytoplasmic dyneinmediated transport of vesicles along microtubules and, thus, may be an essential component of retrograde axonal transport. In vivo, a dominant mutation in the Drosophila homologue of p150Glued induces aberrant neuronal development when heterozygous and is lethal when homozygous. In order to characterize the role of the dynactin complex in the development and function of vertebrate neurons, the distribution of the p150Glued message was examined via in situ hybridization to serial sections of adult rat brain and to a developmental series of sections. In the adult rat brain, the most intense hybridization observed with the p150Glued probe was in the pyramidal cells of the hippocampus proper, the dentate granule neurons, the cingulate and piriform cortices, the ventromedial hypothalamus, and the granular cell layer of the cerebellum. White‐matter fiber tracts and the neuropil were generally devoid of signal. The data indicate that the mRNA encoding p150Glued is highly enriched in the cell bodies of neurons within the central nervous system. In developing rat, p150Glued is expressed at very high levels in neural tissue from the earliest time points assayed. Particularly intense hybridization was observed in the multiple layers of the retina, which is consistent with the phenotype of the Drosophila mutation. Therefore, the distributions observed via in situ hybridization are consistent with an essential role for p150Glued in retrograde axonal transport. © 1995 Wiley‐Liss, Inc.
Localisation, quantitation, and characterisation of neuropeptide F‐ and FMRFamide‐immunoreactive peptides in turbellarians and a monogenean: A comparative study
Authors: Johnston R. N. , Shaw C. , Brennan G. P. , Maule A. G. , Halton D. W. 
Published: January 2005

AbstractOver the past decade it has become clear that the nervous systems of platyhelminths are both complex and highly developed, particularly in peptidergic elements. The central position of an ancestral flatworm in the evolution of the Bilateria, has placed a greater importance on the study of modern flatworms. Using antisera generated to the C‐terminal region of platyhelminth neuropeptide F and the molluscan neuropeptide, FMRFamide, in immunocytochemistry at both light and ultrastructural levels, immunoreactivities have been localised within the nervous systems of three species of triclad turbellarians, Dugesia lugubris, Dendrocoelum lacteum, and Polycelis nigra, and one species of monogenean trematode, Diclidophora merlangi. Extensive immunostaining was obtained with both antisera throughout the central and peripheral nervous systems of all species studied, but intensity and abundance was significantly greater in the turbellarians. Indirect electron‐immunogold labeling demonstrated that immunoreactivity to both neuropeptides was often colocalised in neurosecretory vesicles, although discrete populations of vesicles were also observed. Radioimmunoassay of extracts of all species confirmed that neuropeptide F immunoreactivity was consistently more abundant than FMRFamide immunoreactivity, and that the levels of both in the three turbellarians were several orders of magnitude greater than those found in the monogenean. Chromatographic analyses of turbellarian extracts revealed that neuropeptide F and FMRFamide immunoreactivities were attributable to different peptides. These data imply that the neuropeptidergic systems of turbellarians are considerably more extensive than those of monogeneans, and would suggest that a regression has occurred in the latter as a consequence of the adoption of a more sedentbxy parasitic lifestyle. © 1995 Wiley‐Liss, Inc.
Spatial distribution of thalamic projections to the supplementary motor area and the primary motor cortex: A retrograde multiple labeling study in the macaque monkey
Authors: Shindo Katsuhiro , Shima Keisetsu , Tanji Jun 
Published: January 2005

AbstractThe exact knowledge on spatial organization of information sources from the thalamus to the supplementary motor area (SMA) and to the primary motor cortex (MI) has not been established. We investigated the distribution of thalamocortical neurons projecting to forelimb representations of the SMA and the MI using a multiple retrograde labeling technique in the monkey. The forelimb area of the SMA, and the distal and proximal forelimb areas of the MI were identified by electrophysiological techniques of intracortical microstimulation and single neuron recording. Injections were made into these three representations with three different dyes in the same animal (horseradish peroxidase conjugated to wheat germ agglutinin, diamidino yellow, and fast blue), and the thalamic neurons were retrogradely labeled. Injections into the SMA densely labeled thalamic neurons in nuclei ventralis lateralis pars oralis (VLo), ventralis lateralis pars medialis (VLm) and ventralis lateralis pars caudalis (VLc), but not in nucleus ventralis posterior lateralis pars oralis (VPLo). Injections into the MI labeled thalamic neurons primarily in VLo, VLc, and VPLo. We found that the distribution of projection neurons to the three areas was largely separate in the thalamus. However, in the middle part of VLo, and in a limited portion of VLc, thalamic neurons projecting to the SMA partially overlapped with those to the distal forelimb area of the MI. They overlapped little with those to the proximal forelimb area of the MI. We noted no overlap between the distributions of thalamic projection neurons to the distal and proximal forelimb areas of the MI. These findings suggest that the SMA and MI receive separate information from the thalamus, while sharing minor sources of common inputs. © 1995 Wiley‐Liss, Inc.