bluuebunny/crossref_metadata_2025_split huggingface dataset:
A quantitative light and electron microscopic analysis of taurine‐like immunoreactivity in the dorsal horn of the rat spinal cord
Authors: Lee Inse S. , Renno Waleed M. , Beitz Alvin J. 
Published: January 2005

AbstractTaurine has been proposed as an inhibitory neurotransmitter or neuromodulator in the vertebrate central nervous system. Within the spinal cord, taurine has been shown to have a direct inhibitory effect on spinal neurons and to have a selective antinociceptive effect on chemically induced nociception. Although sufficient data exists to suggest that taurine plays a neurotransmitter or neuromodulatory role in the spinal cord, it is not known whether this amino acid is present in axon terminals nor if this amino acid has a unique pattern of distribution within spinal tissue. To address these questions a monoclonal antibody against taurine was employed to localize taurine‐like immunoreactivity in the dorsal horn of the rat spinal cord by using both light and electron microscopic techniques. Taurine‐like immunoreactivity was most dense and most prominent in laminae I and II of the dorsal horn. A moderate amount of immunoreactivity was also present in laminae VIII and IX and X while the remaining laminae were only lightly stained. In laminae I and II taurine‐like immunostaining was evident within neuronal cell bodies, dendrites, myelinated and unmyelinated axons, axon terminals, and astrocytes and their processes. Cell counts of these two laminae indicated that approximately 30% of neuronal perikarya at the C2 level, 52% of neuronal perikarya at the T6 level, and 18% of neuronal perikarya at the L2 level of the cord exhibited taurine‐like immunoreactivity. With preembedding diaminobenzidine staining, approximately 20% of the axons examined in laminae I and II were found to be immunoreactive for taurine. Using postembedding immunogold staining in combination with quantitative procedures, the highest densities of gold particles were found in axon terminals containing pleomorphic vesicles and forming symmetrical synapses (36.8 particles/μm2), in a subpopulation of myelinated axons (34.2 particles/μm2), in a subpopulation of neuronal dendrites (32.6 particles/μm2), and in capillary endothelial cells (39.8 particles/μm2). Moderate labeling occurred in astrocytes (20.9 particles/μm2) and neuronal perikarya (18.7 particles/μm2). The localization of taurine to presumptive inhibitory axon terminals provides anatomical support for the hypothesis that taurine may serve an inhibitory neurotransmitter role in the superficial dorsal horn of the spinal cord. On the other hand, its localization to astrocytes and endothelial cells within both the dorsal ventral horns implies that it serves other nonneuronal functions as well. © 1992 Wiley‐Liss, Inc.
Morphology of bipolar cells labeled by DAPI in the rabbit retina
Authors: Mills Stephen L. , Massey Stephen C. 
Published: January 2005

AbstractThe morphology, distribution, and coverage of certain cone bipolar cell types were investigated in rabbit retina. Brief in vitro incubation of isolated rabbit retina in the fluorescent dye 4,6‐diamino‐2‐phenylindole labeled only a few cell types in the inner nuclear layer. Intracellular injection of Lucifer Yellow into these types showed them to be horizontal cells and cone bipolar cells. All stained bipolar cells ramified in sublamina a of the inner plexiform layer (IPL) and formed three classes. Two types ranged from 20 to 60 μm in diameter in both plexiform layers; the other large bipolar cell was 40–70 μm in diameter in the outer plexiform layer (OPL) and up to 150 μm in diameter in the IPL. The brightest type was narrowly stratified in the outer portion of sublamina a. Its density increased from about 500 cells/mm2 in the periphery to about 2,500 cells/mm2 in the visual streak. Staining of neighboring cells of this type showed that processes in the IPL rarely crossed, but often converged at a common site so as to impart a “honeycomb” appearance to a single sublayer of retina. The other small bipolar cell was similar in density and coverage, but stratified diffusely throughout sublamina a. The large bipolar cell stratified narrowly in the distal portion of sublamina a and was more sparsely distributed. Whether determined by staining adjacent cells or by density vs. area calculations, coverage in the OPL approached 1 for each type, as did coverage in the IPL for the two types with narrow fields. © 1992 Wiley‐Liss, Inc.
Retinal growth and cell addition during embryogenesis in the teleost, Haplochromis burtoni
Authors: Hagedorn Mary , Fernald Russell D. 
Published: January 2005

AbstractNeurogenesis of the developing embryonic retina is described for the African cichlid fish, Haplochromis burtoni, from 4 days post fertilization until all cell phenotypes are generated (day 7). Cell addition and differentiation both begin at the same absolute location which later becomes the central retina. As observed in most other vertebrates, cones and ganglion cells differentiate first, followed by amacrine and bipolar cells. Rod photoreceptors, which are added late, differentiate last. Changes in retinal thickness, retinal stretching, cell size, and cell density were measured during development. From day 4 through 7, there is an increase in retinal thickness largely due to the expansion of the inner plexiform layer (IPL) and outer nuclear layer (ONL). The inner nuclear layer (INL) decreases in thickness and there is a transient decrease in the density of cells in the scleral portion of the INL. Cells increase in size in the ganglion cell layer (GCL) and the vitread INL, decrease in size in the sclerad INL, and remain the same in the ONL. Changes in the density of the cell layers were observed: the density of ONL cells increased, the density of GCL cells decreased, and INL cells increased then decreased. From day 4 to day 6, eye growth is entirely due to cell addition because no retinal stretching was observed in the ONL or the horizontal layer.During this same developmental period, the pattern and rate of neurogenesis were measured in the differentiated portion of the retina by means of 3H‐thymidine labeling. A small number of cell divisions within the differentiated INL precede the onset of cell divisions in the ONL. The number of 3H‐thymidine labeled cells within the INL increases at a low rate consistent with an asymmetric pattern of cell division characteristic of stem cells. In contrast, cell divisions in the ONL increase exponentially, consistent with a symmetric pattern of cell division characteristic of progenitor cells. Double‐label experiments (3H‐thymidine and a rod specific opsin antibody) show that some of the symmetrically dividing cells in the ONL express the rod specific opsin within 2 days, suggesting that these dividing cells are rod progenitors. Although we do not have conclusive evidence, these developmental processes support the hypothesis that stem cells within the INL could be the source of rod precursors in the embryonic teleost retina. © 1992 Wiley‐Liss, Inc.
Light and electron microscopic characterization of dopamine‐immunoreactive axons in human cerebral cortex
Authors: Smiley John F. , Williams S. Mark , Szigeti Klara , Goldman‐Rakic Patricia S. 
Published: January 2005

AbstractThe distribution and synaptic connections of dopamine axons were studied by light and electron microscopy in human cerebral cortex. For this purpose, dopamine immunoreactivity was characterized in apparently normal anteriolateral temporal cortex, which was removed to gain access to the medial temporal lobe during tumor excision or treatment of epilepsy. Nissl sections showed this to be granular neocortex. Dopamine fibers were distributed throughout this cortex, although there were relatively more fibers in layers I–II and in layers V–VIa, compared to layers III–IV and VIb, resulting in a bilaminar pattern of labeling. In all layers, fibers were seen to form numerous varicosities, and to vary in size from thick to very fine. Fibers were relatively straight, sparsely branched and were oriented in various planes within the cortex. However, in layer I, they often ran parallel to the pial surface.In order to analyze the functional interactions of dopamine fibers, individual cortical layers were surveyed for dopamine synapses. These were usually symmetrical (Gray's type II), although 13% of them were asymmetrical. Approximately 60% of dopamine synapses were made with dendritic spines, and 40% with dendritic shafts, and this ratio was similar in all layers. On both spines and shafts, it was common to see dopamine synapses closely apposed to an unlabeled asymmetric input, suggesting a dopamine modulation of excitatory input. Some postsynaptic dendritic shafts had features of pyramidal cells, including formation of spines. Since pyramidal cells are the major type of cortical spiny neuron, they probably represent the main target of dopamine synapses in this cortex. There were also dopamine profiles apposed to membrane densities on unlabeled axon terminals, suggesting another type of synaptic interaction. These findings provide the first documentation of dopamine synapses in the human cortex, and show that they form classical synaptic junctions. The location of these synapses on spines and distal dendrites, and their proximity to asymmetric synapses, suggest a modulatory role on excitatory input to pyramidal cells. © 1992 Wiley‐Liss, Inc.
Area 3a in the cat. I. A reevaluation of its location and architecture on the basis of Nissl, myelin, acetylcholinesterase, and cytochrome oxidase staining
Authors: Avendaño Carlos , Verdu Alfonso 
Published: January 2005

AbstractCurrent knowledge on the anatomy of area 3a of the cat mainly derives from the cyto‐ and myeloarchitectonic study of Hassler and Muhs‐Clement (J Hirnforsch 6:377, 1964). Previous investigations in the cat had failed to identify a cortical region comparable to monkey's area 3a. In the present study, Nissl, myelin, acetylcholinesterase, and cytochrome oxidase staining techniques were applied to coronal and sagittal serial sections of the cat brain. Area 3a appears as a slender band of cortex between areas 4 and 3b, and in Nissl‐stained sections it is mainly characterized by an attenuated granular layer IV, overlying a thin layer V with pyramidal cells of various sizes, including a few large ones. These cytoarchitectonic features are sufficient to differentiate area 3a from neighboring areas, although the borders between them are not sharp in many cases. After the Nissl staining, the acetylcholinesterase staining proved to be the most helpful in defining the structure and borders of area 3a. Acetylcholinesterase staining was dense in layer I (in contrast with a lighter staining of outer layer I in area 4), and light in layers II and IIIa, changing to moderate in IIIc and IV (a pattern which is accentuated in area 3b). Myelin and cytochrome oxidase techniques also yielded differential staining patterns of area 3a and neighboring areas 4 and 3b, although the borders were not easily drawn with these techniques. Whereas our cyto‐ and myeloarchitectonic findings were comparable to those of Hassler and Muhs‐Clement ('64) and applied well to area 3a in the convexity of the hemisphere, we found that most of the area 3a described by these authors in the medial face of the hemisphere had a number of distinguishing architectonic (as well as connectional and physiological) features which enabled us to define it as a separate area (7m). The techniques we used to delineate area 3a are compatible with most current procedures of histo‐ and immunohistochemical staining of the brain, and may also provide valuable supporting data for electrophysiological studies. © 1992 Wiley‐Liss, Inc.
Restoration of ascending noradrenergic projections by residual locus coeruleus neurons: Compensatory response to neurotoxin‐induced cell death in the adult rat brain
Authors: Fritschy Jean‐Marc , Grzanna Reinhard 
Published: January 2005

AbstractThere is clinical and experimental evidence that monoamine neurons respond to lesions with a wide range of compensatory adaptations aimed at preserving their functional integrity. Neurotoxin‐induced lesions are followed by increased synthesis and release of transmitter from residual monoamine fibers and by axonal sprouting. However, the fate of lesioned neurons after long survival periods remains largely unknown. Whether regenerative sprouting may contribute significantly to recovery of function following lesions which induce cell loss has been questioned. We have previously analyzed the response of locus coeruleus (LC) neurons to systemic administration of the noradrenergic (NE) neurotoxin N‐(2‐chloroethyl)‐N‐ethyl‐2‐bromobenzylamine (DSP‐4) to adult rats. This drug causes ablation of nearly all LC axon terminals within 2 weeks after administration, followed by a profound loss of LC cell bodies 6 months later. The present study was conducted to determine the fate of surviving LC neurons and to characterize their potential for regenerative sprouting during a 16 month period after DSP‐4 treatment. The time‐course and extent of LC neuron degeneration were analyzed quantitatively in Nissl‐stained sections, and the regenerative response of residual neurons was characterized by dopamine‐β‐hydroxylase immunohistochemistry. The results document that LC neurons degenerate gradually after DSP‐4 treatment, cell loss reaching on average 57% after 1 year. LC neurons which survive the lesion exhibit a vigorous regenerative response, even in those animals in which cell loss exceeds 60–70%. This regenerative process leads progressively to restoration of the NE innervation pattern in the forebrain, with some regions becoming markedly hyperinnervated. In stark contrast to the forebrain, very little reinnervation takes place in the brainstem, cerebellum and spinal cord. These findings suggest that regenerative sprouting of residual neurons is an important compensatory mechanism by which the LC may regain much of its functional integrity in the presence of extensive cell loss. Furthermore, regeneration of LC axons after DSP‐4 treatment is region‐specific, suggesting that the pattern of reinnervation is controlled by target areas. Elucidation of the factors underlying recovery of LC neurons after DSP‐4 treatment may provide insights into the compensatory mechanisms of central neurons after injury and in disease states. © 1992 Wiley‐Liss, Inc.
Sex differences in the gross size of the rat neocortex
Authors: Reid Silvia N. M. , Juraska Janice M. 
Published: January 2005

AbstractThe pervasiveness of sex differences in the size of the rat cerebral cortex was investigated in ten littermate pairs of socially housed Long‐Evans hooded rats at 90 days of age. Overall, the cortex was longer and wider in male than in female rats. Sex differences were detected in most cortical regions with this sample size; the exception was the temporal cortex. While some asymmetries were found, they did not vary with the sex of the animal nor were they consistently in one direction. The contribution of the cortical layers to sex differences in cortical thickness was examined in four locations: the primary motor cortex, the forelimb area of the sensorimotor cortex and the monocular and the binocular areas of the visual cortex. The layers that showed sex differences varied among the areas but were confined to layers II–III, V and VI. Sex differences in cortical size were widespread in the adult rat but showed some regional and laminar specificity. © 1992 Wiley‐Liss, Inc.
Development of high‐affinity choline transport sites in rat forebrain: A quantitative autoradiography study with [3H]hemicholinium‐3
Authors: Happe H. K. , Murrin L. C. 
Published: January 2005

AbstractThe development of cholinergic terminals in rat brain has been quantitatively analyzed by [3H]hemicholinium‐3 autoradiography. [3H]Hemicholinium‐3 binds to high affinity choline transport sites, a specific marker for cholinergic neurons. In neonatal animals, kinetic and pharmacologic binding characteristics and regional distribution of [3H]hemicholinium‐3 sites are consistent with specific cholinergic localization, as in the adult. The distribution of cholinergic terminals is described in the adult rat brain and during development, including heterogeneity of binding within several regions such as the striatum, nucleus accumbens, olfactory tubercle, cortex, and hippocampus. Early development and maturation vary greatly between brain regions. At embryonic day E18 and day 0, specific binding density is high only in the medial habenula. Development occurs primarily during the postnatal period in most brain regions examined. Many brain regions exhibit a lull in development between days 5 and 10, although the rate of development is highly region specific. Specific binding increases 2–12‐fold between day 5 and adult animals, with adult density being achieved anywhere from day 15 to after day 21. The ontogeny of [3H]hemicholinium‐3 binding sites generally occurs in a rostral to caudal direction. In the striatal body the characteristic lateral to medial gradient of binding site density is apparent by day 5, and development is more rapid in the lateral striatum. Patches of dense [3H]hemicholinium‐3 binding coincident with acetylcholinesterase are observed on day 5 in the caudal striatum. The various patterns of cholinergic terminal development suggest that factors regulating cholinergic development are regional and complex. © 1992 Wiley‐Liss, Inc.
Distribution of the mRNA for a metabotropic glutamate receptor (mGluR1) in the central nervous system: An in situ hybridization study in adult and developing rat
Authors: Shigemoto Ryuichi , Nakanishi Shigetada , Mizuno Noboru 
Published: January 2005

AbstractDistribution of the mRNA for a metabotropic glutamate receptor (mGluR1), which is linked to phosphoinositide (PI) hydrolysis, was investigated in adult and developing rat central nervous system (CNS) by in situ hybridization. Transcripts of mGluR1 were specifically localized to neurons and widely distributed throughout the adult rat brain. Most intensely labeled neurons were Purkinje cells of the cerebellum, mitral and tufted cells of the olfactory bulb, and neurons in the hippocampus, lateral septum, thalamus, globus pallidus, entopeduncular nucleus, ventral pallidum, magnocellular preoptic nucleus, substantia nigra, and dorsal cochlear nucleus. Moderately labeled neurons were seen in high density in the dentate gyrus, striatum, islands of Calleja, superficial layers of the retrosplenial, cingulate and entorhinal cortices, mammillary nuclei, red nucleus, and superior colliculus. In the developing rat brain, the level of mGluR1 expression gradually increased during early postnatal days in accordance with the maturation of neuronal elements.These results show prominent expression of mGluR1 in the major targets of putative glutamatergic pathways and unique distribution pattern of mGluR1 distinct from those reported for ionotropic subtypes of glutamate receptors, suggesting specific roles of mGluR1 in the glutamatergic system. © 1992 Wiley‐Liss, Inc.
Innervation of the amphibian and basilar papillae in the leopard frog: Reconstructions of single labeled fibers
Authors: Simmons D. D. , Bertolotto C. , Narins P. M. 
Published: January 2005

AbstractAmphibians have two auditory organs specialized for reception of airborne sounds: the amphibian papilla and the basilar papilla. In this report we examine the morphology of the ganglion cells and the afferent innervation of the sensory epithelium in both auditory organs of the leopard frog, Rana pipiens pipiens. Extracellular injections of either biocytin or horseradish peroxidase (HRP) were made into the VIII nerve; they labeled ganglion cells, their axons, and their terminal fibers within the papillae. Ganglion cells that projected to either the amphibian papilla or basilar papilla had cell bodies that were morphologically distinct from other labeled cells. In the amphibian papilla thick fibers terminated in the rostral portion and thin fibers terminated in the caudal portion. Labeled fibers in the rostral portion traveled short distances before making contacts with up to nine hair cells whereas labeled fibers in the caudal portion traveled longer distances and contacted no more than five hair cells. In the basilar papilla labeled fibers were thick (around 4 μm) and terminated on as many as nine hair cells. Consistent with studies from the bullfrog, Rana catesbeiana, our results suggest that the amphibian papilla of R. pipiens pipiens has a convergent innervation (i.e., multiple hair cells provide input to a single ganglion cell) and is topographically organized. However, in contrast to reports in other ranid species, a highly convergent innervation like that found in the amphibian papilla is also found in the basilar papilla. © 1992 Wiley‐Liss, Inc.
Calcitonin gene‐related peptide in afferents to the cat's cerebellar cortex: Distribution and origin
Authors: Bishop Georgia A. 
Published: January 2005

AbstractIn the present study, the distribution and origin of calcitonin gene‐related peptide (CGRP) were analyzed in the cat's cerebellum. Following incubation in an antibody generated against rat CGRP and processing with the peroxidase anti‐peroxidase (PAP) technique, CGRP immunoreactivity (IR) is found in profiles that have morphological characteristics of both simple and complex mossy fibers. However, all mossy fibers are not CGRP‐positive. Further, CGRP‐IR mossy fibers have a heterogeneous distribution in the cerebellum. In the vermis, the majority of immunoreactive profiles are in lobules VII, VIII, and the dorsal folia of IX. In anterior vermal lobules, only scattered terminals, located primarily at the apex and along the shoulder of the folia, are present. Laterally, CGRP‐IR mossy fibers are located in the paramedian lobule, paraflocculus, and crus II. No CGRP fibers or varicosities are observed in any of the cerebellar nuclei. However, CGRP‐positive cell bodies are scattered throughout the nuclear neuropil. A double label technique revealed that CGRP‐IR mossy fibers arise from neurons located in the lateral reticular nucleus, external cuneate nucleus, inferior vestibular nucleus, and basilar pons. The present findings, taken together with previous data, indicate that cerebellar afferents are chemically heterogeneous. The findings of the present study suggest that precerebellar nuclei that give rise to the mossy fibers that contain CGRP have the potential for playing a complex role in modulating circuitry in the cerebellar cortex of the cat. © 1992 Wiley‐Liss, Inc.