bluuebunny/crossref_metadata_2025_split huggingface dataset:
Parallel pathways and convergence onto HVc and adjacent neostriatum of adult zebra finches (Taeniopygia guttata)
Authors: Fortune Eric S. , Margoliash Daniel 
Published: January 2005

AbstractThe structure and connectivity of the forebrain nucleus HVc, a site of sensorimotor integration in the song control system of oscine birds, were investigated in adult zebra finches. HVc in males comprises three cytoarchitectonic subdivisions: the commonly recognized central region with large and medium‐sized darkly staining cells, a ventral caudomedial region with densely packed small and medium‐sized cells, and a dorsolateral region with oblong cells and rows of cells. All three subdivisions project to area X and the robust nucleus of the archistriatum, with more complexity in the classes and distribution of cells than previously reported. In females, HVc is very small and has a cytoarchitecture distinct from that of the three male subdivisions. The structure of HVc in females treated with estradiol at 15 days of age is similar to male HVc.Tracer studies in males with fluorescent and biotinylated dextrans demonstrate non‐topographic projections onto HVc that may carry auditory information, including type 1 and type 2 neurons in subdivisions L1 and L3 of the field L complex, a class of neurons in nucleus interface, nucleus uvaeformis, the caudal neostriatum ventral to HVc, and intrinsic HVc connections. These data are interpreted in terms of HVc's functional properties. Additionally, the neostriatum immediately ventral to HVc receives projections from field L, ventral hyperstriatum, and caudal neostriatum, and projects to a region surrounding RA and near to or into area X. The similarity of the connectivity of HVc and adjacent neostriatum suggests the possibility that they share a common origin. © 1995 Wiley‐Liss, Inc.
Asymmetrical blastomere origin and spatial domains of dopamine and neuropeptide Y amacrine subtypes in Xenopus tadpole retina
Authors: Huang Sen , Moody Sally A. 
Published: January 2005

AbstractAmacrine cells are located almost exclusively in the inner nuclear layer (INL) of the retina, but they express a variety of neurotransmitters. To begin to elucidate the relative roles of the local environment and cell lineage in determining the different neurotransmitter subtypes of amacrine cells, we combined lineage tracing and immunocytochemical techniques to map the spatial distribution and clonal origin of dopamine (DA) and neuropeptide Y (NPY) amacrine cells in Xenopus tadpole retina. At the earliest period of neurotransmitter expression, both DA and NPY amacrine cells were distributed preferentially in center and intermediate annular regions, and in anterior and dorsal quadrants. Most of the DA and NPY cells first emerged as scattered cells and later as clusters (of 2 or more cells) that increased in number and size up to premetamorphic stages. These results suggest that DA and NPY amacrine subtypes may be influenced by environmental cues localized to specific regions of the retina. Lineage analysis showed that the percentage of DA or NPY amacrine cells produced by most blastomere progenitors is significantly different from that predicted by the number of cells in the retina produced by those blastomeres. Only two blastomeres produced over 90% of the DA amacrine cells and only four produced 97% of the NPY amacrine cells. Some retinal progenitors did not contribute at all to these two amacrine subtypes. There also is a marked asymmetry in the blastomere origin of DA and NPY amacrine cells. Two retinal progenitors produced significant numbers of NPY but very few DA amacrine cells. This analysis provides evidence that blastomere origin restricts the developmental choices of retinal progenitors. © 1995 Wiley‐Liss, Inc.
Distribution of small vasopressinergic neurons in golden hamsters
Authors: Ferris Craig F. , Delville Yvon , Miller Margaret A. , Dorsa Daniel M. , De Vries Geert J. 
Published: January 2005

AbstractIn rats, small (diameter: ca. 10 μm) vasopressinergic neurons have been localized in the forebrain, including extrahypothalamic sites, such as the bed nucleus of the stria terminalis (BST) and the medial amygdala (MeA). In golden hamsters, no such neurons have ever been described in extrahypothalamic sites, while their presence in some hypothalamic sites, such as the paraventricular nucleus (PVN), remains controversial. The present studies were carried out to confirm the existence of small vasopressinergic neurons in the forebrain of golden hamsters, using rats as a positive control. The presence of small vasopressinergic neurons in these sites was first tested by imrnunocytochemistry in colchicine‐treated animals. The resulting distribution was corroborated by in situ hybridization for vasopressin (AVP) mRNA. While a large number of small AVP‐immunoreactive (AVP‐ir) neurons was found in the BST and MeA of colchicine‐treated rats, none was found in the same locations in hamsters. Interestingly, as a few large (diameter: 20–25 μm) AVP‐ir neurons were found in the BST just medial to the small neurons in rats, the same area contained a few large and small AVP‐ir neurons in hamsters. In the PVN, large and small AVP‐ir neurons were found in rats and hamsters. However, three to four times more neurons were counted in rats. These data were confirmed by in situ hybridization. Indeed, in hamsters, no labelling for AVP mRNA was detected in small neurons within the BST and MeA. Furthermore, the PVN of rats contained more labelling for AVP mRNA, as compared to hamsters. These results confirm that the distribution of vasopressiner gic neurons in rats cannot be generalized to other species without a detailed analysis. © 1995 Wiley‐Liss, Inc.
Distinct morphological characteristics of touch, temperature, and mechanical nociceptive neurons in the crotaline trigeminal ganglia
Authors: Liang Yun‐Fei , Terashima Shin‐Ichi , Zhu Al‐Qing 
Published: January 2005

AbstractIntrasomal recording and horseradish peroxidase injection techniques were employed in vivo to determine the morphological characteristics of touch, temperature, and mechanical nociceptive neurons in the trigeminal ganglia of crotaline snakes. The touch neurons, with a peripheral axon conducting at the A–β range, could be subdivided into tactile and vibrotactile neurons according to their response properties, but there were no morphological differences between them. These neurons exhibited a large and oval soma and possessed a set of large stem, peripheral, and central axons which were all myelinated and equal in diameter with a constriction at the bifurcation. The temperature neurons, which conducted peripherally at the A‐δ; range, were physiologically separated into thermosensitive and thermo‐mechanosensitive neurons, which were also morphologically indistinguishable. The temperature neurons had a round soma of medium size and a set of medium axons with varied axonal bifurcation patterns. All axons of these neurons were myelinated, but the central axon was thinner than the stem and peripheral axons. The mechanical nociceptive neurons, which had a peripheral axon conducting at the A‐δ range, were morphologically heterogeneous based on their conduction velocities. The neurons conducting at the fast A‐δ range were morphologically similar to the temperature neurons in the ganglion excepting their thinner central axons, whereas those at the slow A‐δ range had a thinner myelinated stem axon that gave rise to a thinner myelinated peripheral axon and an unmyelinated central axon with a bifurcation of either a triangular expansion at the bifurcating point or a central axon arising straightforwardly from the constant stem and peripheral axons. This study revealed that distinct morphological characteristics do exist for the touch and temperature neurons and the subtypes of mechanical nociceptive neurons in the trigeminal ganglion, but not for the subfunctional types of touch neurons or temperature neurons. © 1995 Wiley‐Liss, Inc.
Non‐uniform distribution of cellular phenotypes in the optic tectum of the leopard frog
Authors: Debski Elizabeth A. , Liu Qin , Chapman Angela M. 
Published: January 2005

AbstractRegional specializations in the retina have been described in a number of species. We have investigated whether such specializations can be found in the optic tectum, an area of the brain responsible for the processing of visual information. Using the tectum of Rana pipiens, we have examined the distribution of three different cell types defined on the basis of their immunoreactivity to somatostatin, substance P, and serotonin antibodies. These three immunoreactive cell populations had differing, nonuniform distributions in the optic tectum. Somatostatin‐like irnmunoreactive cells were largely restricted to the caudal one‐third of the tectum, whereas both substance P‐like immunoreactive (SP‐ir) and serotonin‐like immunoreactive (5‐HT‐ir) cells were found unequally represented throughout the tectum. The percentage of SP‐ir cells decreased significantly in both the posterior and medial directions from its high in the anterior lateral tectum. Although serotonin‐like immunoreactivity was also greatest in the lateral tectum and decreased significantly medially, it was largely constant in the anterior‐to‐posterior dimension. The populations of SP‐ir and 5‐HT‐ir cells were nonoverlapping. Our results suggest that information may be processed differently in different regions of the optic tectum. © 1995 Wiley‐Liss, Inc.
Two rules for callosal connectivity in striate cortex of the rat
Authors: Lewis James W. , Olavarria Jaime F. 
Published: January 2005

AbstractIn the rat, callosal cells occupy lateral as well as medial portions of striate cortex. In the region of the border between areas 17 and 18, which contains a representation of the vertical meridian of the visual field, cells projecting through the corpus callosum are concentrated throughout the depth of the cortex. In contrast, in medial portion of striate cortex, where peripheral portions of the visual field are represented, callosal cells are preferentially found in infragranular layers. These differences in topography and laminar distribution suggest that these callosal regions, referred to as medial and lateral callosal regions in the present study, subserve different functions. We explored this possibility by analyzing the patterns of callosal linkages in these two cailosai regions. We charted the location of retrogradely labeled cells within striate cortex of one hemisphere after placing restricted injections of one or more fluorescent tracers into selected sites in the contralateral striate cortex.We found the medial and lateral callosal regions have distinctly different topographic organizations. Injections into medial striate cortex of one hemisphere produced labeled cells predominantly in mirror‐symmetric loci in medial portions of contralateral striate cortex. The arrangement of these connections suggests that they mediate direct interactions between cortical regions representir visual fields located symmetrically on opposite sides of the vertical meridian of the visual field. In contrast, the mapping in the lateral callosal region is reversed: injections into the 17/18a border produced labeled fields located medial to the contralateral 17/18a border, while injections slightly medial to the 17/18a border produced labeled fields located at the contralateral 17/18a border. Assuming that lateral striate cortex represents aportion of the ipsilateral visual field, this reversal in the callosal mapping suggests that callosal fibers in the lateral callosal region interlink cortical loci representing similar portions of the visual field. © 1995 Wiley‐Liss, Inc.
Distribution of brainstem projections from spinal lamina I neurons in the cat and the monkey
Authors: Craig A. D. (Bud) 
Published: January 2005

AbstractThe distribution of terminal projections in the brainstem from lamina I neurons in the spinal dorsal horn was investigated with the anterograde tracerPhaseolus vulgaris–leucoagglutinin in the cat and the cynomolgus monkey. Iontophoretic injections made with physiological guidance were restricted to lamina I or to laminae I–III in the cervical (C6–8) or lumbar (L6–7) enlargement. The distribution of terminal labeling was essentially identical in the cat and the monkey, although consistently of greater intensity in the monkey. Terminations were observed in the solitary nucleus, the dorsomedial medullary reticular formation, the entire rostrocaudal extent of the ventrolateral medulla, the locus coeruleus, the subcoerulear region and the Kölliker–Fuse nucleus, the lateral and medial portions of the parabrachial nucleus, the cuneiform nucleus, the ventrolateral and lateral portions of the periaqueductal gray, and the intercollicular nucleus. Lamina I terminations were generally bilateral in the medulla but more dense contralaterally in the pons and mesencephalon. The density and laterality of labeling in the medulla varied between cases independently from that in the pons and mesencephalon, suggesting that the lamina I projections to these regions may originate from different subsets of neurons. A clear topographic organization was observed only in the lateral column of the periaqueductal gray, where lumbar lamina I terminations were found caudal to cervical terminations.These observations indicate that spinal lamina I neurons project to a variety of brainstem sites involved in autonomic (cardiovascular, respiratory) and homeostatic processing and the control of behavioral state. These projections provide an afferent substrate for spino‐bulbo‐spinal somatoautonomic reflex arcs activated by nociceptive, thermoreceptive activity and for a spino‐bulbo‐hypothalamic relay of such activity by cells in the caudal ventrolateral medulla. These observations support the general concept that lamina I projections distribute modality‐selective sensory information relevant to the physiological status and maintenance of the tissues and organs of the entire organism. © 1995 Wiley‐Liss, Inc.
Evidence for muscarinic acetyicholine receptor subtypes in the pigeon telencephalon
Authors: Kohler Emlee C. , Messer William S. , Bingman Verner P. 
Published: January 2005

AbstractAt least five subtypes of muscarinic acetyicholine receptors are expressed in various mammalian tissue preparations. The following experiment, through the use of direct binding assays (using tritiated quinuclidinyl benzilate), competitive binding assays (using tritiated quinuclidinyl benzilate and unlabeled pirenzepine or AF‐DX 116), and autoradiographic techniques, examined whether two of these five putative muscarinic acetylcholine receptor subtypes can be found in avian brain. Accordingly, autoradiographic mapping of pirenzepine sensitive (M1‐like) and AF‐DX 116‐sensitive (M2‐like) muscarinic acetylcholine receptor subtypes in the pigeon telencephalon was condu Although both ligands bound throughout the brain, most telencephalic regions, including the archistriatum, the neostriatum, and basal ganglia structures like lobus paraolfactorius, nucleus accumbens, and paleostriatum, showed a higher density of M1‐like sites. The exception to this finding was the nucleus basalis which appeared as a region where M2‐like sites predominated. Moreover, the telencephalic region with the largest ratio of M1‐like to M2‐like sites was the lateral portion of the parahippocampus; a characteristic shared with the mammalian dentate gyrus. The findings reported here are generally consistent with previous reports of mammalian M1/M2 receptor distributions. © Wiley‐Liss, Inc.
Large retinal ganglion cells in the channel catfish (Ictalurus punctatus): Three types with distinct dendritic stratification patterns form similar but independent mosaics
Authors: Cook J. E. , Sharma S. C. 
Published: January 2005

AbstractRetinal ganglion cells in the channel catfish (Ictalurus punctatus) were retrogradely labelled, and those with the largest somata and thickest primary dendrites were categorized by their levels of dendritic stratification. Three types were found, each forming a mosaic making up ∼ 1% of the ganglion cell population. Using a system based on established sublaminar terminology, we call these the alpha‐a (αa), alpha‐b (αb), and alpha‐c (αc) ganglion cell mosaics. Cells of the αa mosaic had large, sparsely branched trees in sublamina a at 10–30% of the depth of the inner plexiform layer (IPL), sclerad to those of all other large ganglion cells. Some αa somata were displaced into the IPL or inner nuclear layer (INL) but belonged to the same mosaic as their orthotopic counterparts. Cells of the αa mosaic had dendrites that branched a little more and arborized in sublamina b at 50–60% of the IPL depth. Many also sent fine branches into sublamina a, and some were fully bistratified in a and b. The αc cells arborized in the most vitread sublamina, sublamina c, at 80–95% of the IPL depth. The soma areas of the three types in the largest retina studied ranged between 139 μm2 and 670 μm2 with significant differences in the order αa > αc ≥ αb. Analyses based on nearest‐neighbour distance (NND) and on spatial auto‐ and cross‐correlograms showed that each mosaic was statistically regular and independent of the others. Mosaic spacings were similar for each type, giving mean NNDs of 242–279 μm in the largest retina and 153–159 μm in a smaller one. Correspondences between these mosaics, previously defined large ganglion cell types in catfish, and other mosaic‐forming large ganglion cells in fish and frogs are discussed along with their implications for neuronal classification, function, development, and evolution. © 1995 Wiley‐Liss Inc.
Migration of A7 immortalized astrocytic cells grafted into the adult rat striatum
Authors: Okoye Godwin S. , Powell Elizabeth M. , Geller Herbert M. 
Published: January 2005

AbstractThe A7 cell line is an SV4O large T antigen‐immortalized astrocyte cell line produced from the neonatal rat optic nerve. Previous studies have demonstrated that A7 cells provide a favorable environment for the survival and growth of cultured neurons and can also stimulate axonal growth after grafting into the rat striatum. The current study was designed to investigate whether A7 cells grafted into adult rat striatum can migrate away from the implantation site. A7 cells were labelled in culture by incorporation of bromodeoxyuridine (BrdU) or by expression of an alkaline phosphatase transgene. The labelled cells were then transplanted into the left striatum of normal adult rats by introducing a blunt‐end 22 gauge needle through a trephine hole. The rats were euthanized at periods of up to 30 days after grafting. The A7 cells did not appear to alter the cytoarchitecture of the surrounding brain parenchyma. Labelled A7 cells were observed in both gray and white matter areas, and many were located in areas free of damage due to the implantation procedure. The migration of the BrdU‐labelled A7 cells with respect to the implantation needle track was determined on coronal sections. The radial migration distance from the needle tract was similarly determined on horizontal sections. A7 cells migrated progressively longer distances with increasing survival time of the animals: The largest migration distance (1,125 ± 52 μ) occurred at 30 days after grafting with an estimated migration rate of 31 μm per day. There was no significant directional polarity in the migration of these cells within the striatum. Some of the labelled A7 nuclear profiles were associated with blood vessels, some appeared to be associated with fiber bundles within the striatum, and some were found within the gray matter without apparent association with any anatomical structure. These results demonstrate that A7 immortalized astrocytic cells migrate away from a single implantation site following grafting into the adult rat striatum to populate a large area of the striatum. © 1995 Wiley‐Liss Inc.
Relationships between the morphology and function of gastric‐ and intestine‐sensitive neurons in the nucleus of the solitary tract
Authors: Zhang Xueguo , Fogel Ronald , Renehan William E. 
Published: January 2005

AbstractThis study employed single cell recording and intracellular iontophoretic injection techniques to characterize and label gastric‐ and/or intestine‐sensitive neurons in the rat nucleus of the solitary tract (NST). It was possible to divide our sample of NST neurons into three broad groups based on their response to increased intra‐gastric and intra‐duodenal pressure. Group 1 cells (N=14) were excited by duodenal distention but were not responsive to gastric stimulation. Most of these intestine‐sensitive neurons exhibited a delayed tonic response to the stimulus. Group 2 neurons (N=13) were excited by gastric distention but were not sensitive to distention of the duodenum. The typical Group 2 neuron evidenced a rapid, phasic response to the distention stimulus. Group 3 neurons (N=29) responded to both gastric and duodenal stimulation. We found that the Group 2 neurons had greater dendritic length and more dendritic branch segments than the Group 1 or Group 3 neurons. Most of the Group 1 neurons were found in the subpostremal/commissural region of the NST, while the majority of the Group 2 neurons were in the gelatinous subnucleus and a disproportionate number of the Group 3 neurons were located in the medial subnucleus. The results of this investigation demonstrate that (1) there are relationships between the morphology and physiology of distention‐sensitive neurons in the NST, and (2) there are distinct functional differences between the gelatinous, medial and commissural subnuclei of this nucleus. © 1995 Wiley‐Liss, Inc.
Peripheral projections of rat primary sensory neurons immunoreactive for neurotrophin 3
Authors: Zhou X.‐F. , Rush R. A. 
Published: January 2005

AbstractSensory neurons can be classified into subpopulations based on a variety of characteristics, including their morphology and physiological modalities. Whether any of these classifications correlates with neurotrophic sensitivities has not been determined, We have recently reported that a subpopulation of large diameter sensory neurons of the rat contain neurotrophin 3‐like immunoreactivity (NT3‐ir). In this study, we have further characterised NT3‐ir sensory neurons by their size, segmental localization, and peripheral projections by combined techniques of retrograde tracing and immunohistochemistry. The size distribution showed that NT3‐ir was localised to a subpopulation of large‐diameter neurons ranging from 560 to 3,120 m Greater numbers of NT3‐ir neurons reside in trigeminal (43% of total), cervical (36%), and lumbar (39%) than in thoracic spinal ganglia (13–17%). In combination with Fluoro‐Gold retrograde tracing, it was found that about 30% of sensory neurons projecting to the tibial muscle were NT3‐ir, compared with 39% for tendon, 50% for whisker hair follicles, 17% for subdermis or epidermis, and only 1% for kidney or adrenal gland. These studies indicate that NT3‐ir sensory neurons mainly project to skin and muscles but not viscera. Thus, the characterization of NT3‐ir spinal sensory neurons suggests that large sensory neurons subserving proprioception and mechanoception require NT3 for the maintenance of normal function. © 1995 Wiley‐Liss, Inc.