bluuebunny/crossref_metadata_2025_split huggingface dataset:
First appearance, distribution, and origin of macrophages in the early development of the avian central nervous system
Authors: Cuadros Miguel A. , Martin Claude , Coltey Pierre , Almendros Antonio , Navascués Julio 
Published: January 2005

AbstractA phagocytic cell system of hemopoietic origin exists in the early avian embryo (Cuadros, Coltey, Nieto, and Martin: Development 115:157–168, '92). In this study we investigated the presence of cells belonging to this system in the central nervous system (CNS) of chick and quail antibodies recognizing cells of quail hemangioblastic lineage. The origin of these cells was traced in interspecific chick–quail yolk sac chimeras. Hemopoietic cells were detected within the CNS from developmental stage HH15 on, and steadily increased in number at subsequent stages. Analysis of yolk sac chimeras revealed that most of these cells were of yolk sac origin, although some hemopoietic cells of intraembryonic origin were also found in the CNS.Immunocytochemical, histochemical, and ultrastructural characterization allowed us to identify hemopoietic cells in the CNS as macrophages. These cells were consistently found in the brain vesicles and spinal cord, appearing (1) between undifferentiated neuroepithelial cells at dorsal levels of the CNS; (2) in areas of cell death; (3) in the marginal layer in close relationship with developing axons; (4) in large extracellular spaces in the subventricular layer; (5) on vascular buds grwoing through the marginal and subventricular layers; and (6) in the ventricular lumen. Macrophages in different locations varied in morphology and ultrastructure, suggesting that in addition to their involvement in phagocytosis, they play a role in other processes in the developing CNS, such as axonal growth and vascular development.The first macrophages migrate to the CNS independently of its vascularization, apparently traversing the pial basal lamina to reach the nervous parenchyma. Other macrophages may enter the CNS together with vascular buds at subsequent stages during CNS vascularization.
Relay cells, not interneurons, of cat's lateral geniculate nucleus contain N‐acetylaspartylglutamate
Authors: Xing Li‐Chuan S. , Tieman Suzannah Bliss 
Published: January 2005

AbstractN‐Acetylaspartylglutamate (NAAG) is an endogenous brain dipeptide that satisfies many of the criteria for a neurotransmitter. We have previously identified NAAG immunoreactivity in neurons of the lateral geniculate nucleus (LGN) of the cat and monkey. To determine whether all LGN neurons contain NAAG, we treated sections of cat LGN with affinity‐purified antibodies to NAAG and counterstained them with thionin. The larger neurons contained NAAG, but the smaller neurons did not. We treated other sections with antiserum to glutamic acid decarboxylase (GAD), the rate‐limiting enzyme in the synthesis of γ‐aminobutyric acid (GABA), in order to label interneurons of the LGN. In these sections, the smaller cells were labeled; the larger neurons were not. We hypothesized that NAAG was present in relay cells, but not interneurons. We used two double‐labeling paradigms to test this hypothesis. We combined immunocytochemistry for NAAG using a fluorescent secondary antibody with either (1) fluorescent retrograde tracers (true blue, granular blue, rhodamine beads, or propidium iodide) injected into areas 17 and/or 18 or (2) immunocytochemistry for GAD using a second fluorescent secondary antibody. In the LGN, over 99% of retrogradely labeled cells contained NAAG, but few GAD‐positive neurons did. In contrast, neurons of the perigeniculate nucleus contained both NAAG and GAD, demonstrating that staining by one set of antisera did not inhibit staining by the other and that perigeniculate neurons are chemically distinct from the interneurons of the LGN. We conclude that in LGN, the relay cells, which project to visual cortex, contain NAAG, whereas most of the interneurons, which contain GABA, do not.
Neuroanatomical distribution and binding properties of saxitoxin sites in the rat and turtle CNS
Authors: Xia Ying , Haddad Gabriel G. 
Published: January 2005

AbstractSince saxitoxin (STX) binds to voltage‐sensitive sodium channels and blocks their function, it has been widely used in the study of these channels. There is, however, limited information on STX binding properties and the neuroanatomical distribution of the Na+ channel as a function of brain region in the rat and in lower vertebrates such as the turtle. In the present study, we used a broad range of 3H‐STX concentration (up to 64 nM) to examine saturation profiles and density distribution in both adult rat and turtle brains. We found that (1) STX sites do not vary greatly in affinity (most Kds = 2 to 5 nM) in various regions of the adult rat brain; (2) STX binding distribution was very heterogeneous in the rat with much higher density in the cortex, hippocampus, amygdala, and cerebellum than in the brainstem and spinal cord; (3) STX sites are mostly localized in layers made mostly of neurons with low density in white matter; and (4) turtle brain STX sites had similar binding properties, but its brain had much fewer STX sites than the rat, especially in the cerebellum and rostral areas such as the cortex. We conclude that (a) adult brain sodium channels have similar STX binding affinity in spite of the existence of multiple sodium channel subtypes; (b) the brainstem is very different from rostral brain areas in channel density; and (c) the turtle brain has a much lower sodium channel density than the rat brain.
Intracellular injection of neurobiotin or horseradish peroxidase reveals separate types of preganglionic neurons in the sacral parasympathetic nucleus of the cat
Authors: Morgan Charles W. , De Groat W. C. , Felkins L. A. , Zhang S.‐J. 
Published: January 2005

AbstractSacral preganglionic neurons are essential to the neural control of the excretory and sex organs. Previously employed multi‐cell tracing methods have certain limitations in the precise morphological analysis of the neural pathways that control these organs. These limitations were overcome by the intracellular injection of neurobiotin or horseradish peroxidase into single preganglionic neurons in the lateral sacral parasympathetic nucleus of the cat. Following light microscopic examination, these neurons, as a group, were found to have an average of five stem dendrites, which divided into 15 dendritic end‐branches that were distributed among eight dendritic terminal fields. These dendrites had a major transverse orientation and were quite long, many of them reaching well into the dorsal and ventral horns and into the dorsal gray commissure. These dendrites also exhibited a major longitudinal orientation, extending an average of 869 μm (combined length of rostral and caudal dendrites) within the nucleus. Two groups of cells emerged on the basis of different dendritic patterns. Cells classed as Type I had dendrites in lamina I and in the ventral horn but lacked a significant projection into the lateral funiculus. Cells classed as Type II had major dendritic projections into the lateral funiculus but lacked dendrites in lamina I. The diverse dendritic patterns of these two cell types indicate dissimilar afferent control mechanisms and suggest that these preganglionic neurons may innervate different target organs. © 1993 Wiley‐Liss, Inc.
Compartmental origin of the striato‐entopeduncular projection in the rat
Authors: Rajakumar N. , Elisevich K. , Flumerfelt B. A. 
Published: January 2005

AbstractThe mammalian neostriatum is divisible into neurochemically and cytoarchitectonically distinct striosome and matrix compartments. This compartmentalization is respected by many afferent and efferent projections of the striatum. The distribution of distinct types of neuroactive substances and receptors and the unique connections of the striosome and matrix suggest a functional segregation between these compartments. The present study examines the organization of efferent projections from each of the striatal compartments to the entopeduncular nucleus (EPN), a major output cente of the basal ganglia.The fluorescent retrograde tracer fluorogold, or rhodamine‐conjugated dextran, was injected into the lateral habenula or the ventrolateral nucleus of the thalamus of adult Wistar rats to identify the topographical organization of EPN‐habenular and EPN‐thalamic neurons. Fluorogold was then placed into the rostral or caudal parts of the EPN, identified from the previous experiment as areas containing predominantly EPN‐habenular or EPN‐thalamic neurons, respectively. Sections containing retrogradely labeled neurons in the neostriatum were simultaneously immunolabeled for calbindin‐D28kDa, a calcium‐binding protein found exclusively in the projection neurons of the matrix. The results indicate that the striatal projection to the EPN‐habenular and EPN‐thalamic parts of the EPN originates from striosome and matrix neurons, respectively. The duality of striatal outflow involving the EPN suggests a mechanism whereby the striosome is integrated into subcortical pathways that modulate the activity of the basal ganglia via the ascending serotoninergic projection from the dorsal raphe nucleus, whereas the matrix is involved in a loop that includes the thalamus and the cerebral cortex. © 1993 Wiley‐Liss, Inc.
Ipsilaterally projecting retinal ganglion cells in Xenopus laevis: An HRP study
Authors: Schütte Michael , Hoskins Sally G. 
Published: January 2005

AbstractThe routes of ipsilaterally projecting retinal ganglion cell axons in the visual pathway of young postmetamorphic Xenopus laevis were studied by anterograde and retrograde transport of horseradish peroxidase (HRP). In the retina, most cells heavily labeled from injections in ipsilateral thalamus are large multipolar ganglion cells. They are found exclusively in the posterior half of the retina, and their axons occupy a central position in the optic nerve head. Immediately behind the eye, axons of ipsilaterally projecting axons leave the core of the nerve and regroup around the circumference of the nerve. The nerve increases in diameter in the region where the fibers reorganize, and pigmented processes are seen in this region of the nerve. At the point where the optic nerve enters the brain case through the optic foramen, the fibers undergo a second reorganization which results in a laminar arrangement of ipsilaterally projecting axons at the ventral margin of the intracranial portion of the nerve. As soon as the nerve touches the brain, uncrossed axons begin to turn toward the ipsilateral side rather than proceeding further towards the midline of the chiasm. These uncrossed axons keep their internal topographical order at least at the beginning of the marginal tract. All ipsilaterally projecting axons run at the rostral edge of the marginal tract at the lateral‐wall of the brain until they reach their terminal fields in the thalamic visual nuclei. © 1993 Wiley‐Liss, Inc.
Purkinje cell dendrites in staggerer ↔ wild type mouse chimeras lack the aberrant morphologies found in lurcher ↔ wild type chimeras
Authors: Soha James M. , Herrup Karl 
Published: January 2005

AbstractIn lurcher ↔ wild type mouse chimeras (lurcher chimeras), mutant Purkinje cells are transiently present and probably provide target support for afferent granule cells during the sensitive period of target‐dependent cell death. Previous studies demonstrate that wild type Purkinje cells in the cerebella of mature lurcher chimeras often have atrophic dendritic morphologies, leading to the hypothesis that development deafferentation of wild type Purkinje cells occurs uniquely in lurcher chimeras following the period of mutant Purkinje cell loss. Other studies document the survival of a disproportionately large number of granule cells in these animals. Based on cell birthdate analyses, the hypothesis further proposes that deafferentation induces an up‐regulation of trophic activity among the Purkinje cell population and the consequent rescue of late generated granule cells that might otherwise be lost to target related cell death. In the present study, we take advantage of phenotypic differences between the staggerer and lurcher mutations to test this hypothesis. While staggerer ↔ wild type chimeras (staggerer chimeras) resemble lurcher chimeras in several respects, including extensive cell loss, they differ in that staggerer Purkinje cells never provide target support for granule cells. Hence the hypothesis predicts that Purkinje cells in these animals should not exhibit the atrophic morphologies found in lurcher chimeras. We have developed a new semiquantitative method for scoring dendritic morphology in a large number of Golgi‐impregnated cells. We have used this method to characterize the distribution of wild type Pukinje cell morphologies in staggerer chimeras, and to compare these with the corresponding distributions of morphologies in lurcher chimeras and wild type ↔ wild type chimeras. We find that morphologies in staggerer chimeras closely resemble those in control chimeras. Furthermore, Purkinje cells in both staggerer and wild type chimeras differ significantly from those in lurcher chimeras. These results confirm a direct prediction of the hypothesis. © 1993 Wiley‐Liss, Inc.
Spatial and temporal differences between the expression of short‐ and middle‐wave sensitive cone pigments in the mouse retina: A developmental study
Authors: Szél Á. , Röhlich P. , Mieziewska K. , Aguirre G. , van Veen T. 
Published: January 2005

AbstractIn an earlier study we found a topographic separation of middlewave‐sensitive (M) and shortwave‐sensitive (S) cones in the adult mouse retina. In the present study we investigated the development of the two colour‐specific cone types to see whether there is also a temporal difference between the expression of the specific cone visual pigments. Using two anti‐cone visual pigment antibodies, COS‐1 and OS‐2, we compared the densities of immunopositive cone outer segments on retinal whole mounts derived from mice of various ages. The first detectable cone outer segments were the S‐cones which appeared in the inferior half of the retina on postnatal day 4. At this stage, the density of the S‐cones was very low (30–40 cones/retina) but increased steadily on the following days to reach a value comparable to that of adults by P30 (18,000/mm2). This cone type always remained much more abundant in the lower part of the retina throughout the whole retinal development. In the superior half of the retina, a few S‐cones appeared from postnatal day 7; however, their number always remained about one order of magnitude lower than in the inferior part.In contrast, M‐cone outer segments were not identifiable earlier than postnatal day 11 and were confined exclusively to the superior part of the retina during the whole development process. On postnatal day 12, their density was 1,900/mm2 and increased to a value of 11,000/mm2 by postnatal day 30, which represented the adult stage. As shown by comparison of isodensity lines derived from immunocytochemical reactions of whole mount retinas, the two cone types occupied complementary halves of the mouse retina with maximum density centres located in opposite retinal quadrants. We conclude that (1) in contrast to the primate retina, mouse S‐cones precede the M‐cones in their development, and (2) the spatial arrangement of the two cone types is maintained throughout the whole differentiation process. © 1993 Wiley‐Liss, Inc.
2‐DG uptake patterns related to single vibrissae during exploratory behaviors in the hamster trigeminal system
Authors: Jacquin Mark F. , McCasland James S. , Henderson Theodore A. , Rhoades Robert W. , Woolsey Thomas A. 
Published: January 2005

AbstractStimulation of one or several whiskers activates discrete foci throughout the trigeminal (V) neuraxis. These foci contribute to patterns, corresponding to the patterns of vibrissae, that have been directly related to aggregates of cells and axon terminals in the “barrel” cortex. Here, we combine high‐resolution, 2‐deoxyglucose (2DG) mapping and cytochrome oxidase (CO) staining to determine whether the known pattern of V primary afferent projections is sufficient to deduce the functional activation of their targets during exploratory behavior. Four adult hamsters had all of their large mystacial vibrissae trimmed acutely, except for C3 on the left, and B2 and D4 on the right; in two others, the left C3 and right A1 and E4 whiskers were spared. After fasting overnight, 2DG was injected and the animals behaved freely in the dark for 45 minutes. The brainstem, thalamus, and cortices were sectioned, then processed for both CO staining and 2DG autoradiography. Image‐processing microscopy was used to separate the autoradiographic silver grains from the histochemical staining.CO patches were patterned in a whiskerlike fashion in the full rostrocaudal extent of V nucleus principalis and in caudal portions of spinal V subnuclei interpolaris and caudalis, but absent in subnucleus oralis. 2DG silver grains were densest above those CO patches in the pattern corresponding to the active whiskers. There were no consistent 2DG foci in subnuclei oralis or rostral caudalais. In these same cases, prominent 2DG labeling was restricted to the appropriate barrels in the contralateral cortex. Only one case, however, displayed a clear and appropriate region of heightened 2DG uptake in contralateral ventroposteromedial thalamus (VPM) and the adjacent part of the reticular thalamic nucleus.Patterns of increased glucose utilization with single whisker stimulation are well matched to the CO patterns that mirror distributions of neurons associated with a vibrissa in the V brainstem complex, thalamus, and cortex. Single whiskers are represented by relatively homogeneous longitudinal columns of 2DG labeling in the V brainstem nuclei. The columns are not continuous through the axial extent of the V brainstem complex; rather, they occur separately within principalis, interpolaris, and caudalis. While whisker columns were consistently labeled in interpolaris and caudalis in all animals, the labeling was increasingly variable in principalis, barrel cortex, and VPM, respectively. This suggests that the behaving animal can and does significantly modulate activity in this major, synaptically secure pathway. © 1993 Wiley‐Liss, Inc.
Spinal cord afferent systems containing the nerve terminal protein NT75
Authors: Kanekar Shami S. , Ritchie Teresa C. , Coulter Joe D. 
Published: January 2005

AbstractIn the adult spinal cord, immunocytochemical staining for NT75 is concentrated in nerve terminals in the superficial laminae of the dorsal horn. Deeper laminae of the dorsal horn contain moderate immunocytochemical labeling, but the ventral horn is only sparsely stained. The origin of spinal nerve terminals containing NT75 was investigated with lesion techniques, colchicine treatment, and retrograde tracing in combination with immunocytochemical staining. Primary afferent neurons express NT75 immunoreactivity and account for most of the dense staining in the superficial dorsal horn and part of the labeling in the deeper laminae. It was found that corticospinal and virtually all brainstem neurons with descending projections to the spinal cord also express NT75 immunoreactivity, including those terminating in the ventral horn. Colchicine treatment of the spinal cord also resulted in NT75 staining in most, if not all, spinal neurons. It appears that neurons in all three major sources of spinal afferents (primary sensory, descending, and intrinsic systems) can express NT75 immunoreactivity, but that some neurons normally contain higher levels of the protein in their nerve terminals. Previous analysis of developing spinal cord has shown widespread, dense NT75 labeling throughout the spinal gray in the early postnatal period, which later becomes restricted to the adult pattern. These studies support the hypothesis that many spinal pathways express high levels of NT75 immunoreactivity during development, but that only certain pathways maintain high levels in the adult. © 1993 Wiley‐Liss, Inc.
Immunocytochemical staining of AII‐amacrine cells in the rat retina with antibodies against parvalbumin
Authors: Wäussle Heinz , Grüunert Ulrike , Röhrenbeck Jürgen 
Published: January 2005

AbstractThe rod dominated rodent retina is the preferred tissue for in vitro studies of mammalian retinal physiology and pharmacology. The rod pathway through the rat retina was investigated, therefore, in order to find out whether its organization follows the mammalian “plan.” AII‐amacrine cells of the rat retina were injected with Lucifer Yellow to characterize the morphology of this bistratified interneuron of the rod pathway. When sections or whole mounts of the rat retina were stained with antibodies against the calcium binding protein parvalbumin (PV), two different amarcine cell types were labeled: the AII‐amacrine cell and a widefield amacrine cell. They occur at a ratio of 12:1. Weak label was also observed in ganglion cells. The density of PV‐labeled AII‐cells decreases from approximately 7,000 cells/mm2 in upper central retina to 2,000 cells/mm2 in peripheral retina. Their cell bodies form a regular mosaic, and the dendritic arbors of three neighbouring AII‐amacrine cells overlap (coverage of 3). © Wiley‐Liss, Inc.
Immunoelectron microscopic analysis of a novel carbohydrate differentiation antigen (CDA‐3C2) in the developing rat olfactory and otic systems
Authors: Prouty Stephen M. , Levitt Pat 
Published: January 2005

AbstractA carbohydrate differentiation antigen (CDA‐3C2) exhibits a highly specific and restricted pattern of expression during rat embryogenesis. In the periphery of the embryo, this antigen is associated transiently with the lateral ectoderm but is retained only in the olfactory and otic epithelium throughout morphogenesis. At the light microscopic level, CDA‐3C2 immunoreactivity appears mostly along cell periphery and in the extracellular matrix. The aim of the present study was to determine the specific cellular and subcellular distribution of CDA‐3C2 in vivo in order to identify potential sites of cellular and tissue function of the antigen during embryogenesis. There was a strikingly similar subcellular distribution of CDA‐3C2 in the developing otic and olfactory systems, found mostly along cell membranes, microvillar projections and acellular secretions of the epithelium. Mature sensory components of the epithelia were not immunoreactive, whereas supportive cells and their secreted structures were densely stained. The highly coincident nature of CDA‐3C2 in both sensory epithelia suggests that this carbohydrate epitope, and possibly its carrier macromolecule, participate in a morphogenetic function common to these two sensory epithelia. © Wiley‐Liss, Inc.