bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunohistochemical localization of thyrotropin‐releasing hormone in the brain of chinook salmon (oncorhynchus tshawytscha)
Authors: Matz Stuart P. , Takahashi Terry T. 
Published: January 2005

AbstractThis report describes the distribution of thyrotropin‐releasing hormone (TRH) immunoreactivity in the brain of juvenile chinook salmon. TRH‐positive cell bodies are observed in the preoptic region of the diencephalon, in the supracommissural nucleus of the ventral telencephalon, and in the internal cellular layer of the olfactory bulb. Immunoreactive fibers occur in the olfactory bulb, the dorsal and ventral telencephalon and were particularly extensive in hypothalamic regions. TRH‐positive fibers also are observed in the optic tectum, posterior pituitary and the brainstem.The cell bodies in the preoptic area reside in the magnocellular preoptic nucleus. The position of these cell bodies along with the location of fibers in the hypothalamus and pituitary is consistent with the role of TRH as a hypothalamic releasing hormone. TRH‐positive cell bodies also occur in the supracommissural nucleus of the ventral telencephalon and in the internal cellular layer of the olfactory bulb. The cell bodies in the olfactory bulb may account for some of the fibers in the telencephalon, as there are TRH fibers in the olfactory tracts. The presence of TRH‐positive, fibers with bouton‐like swellings raise the possibility that the TRH peptide may act as a central neurotransmitter of neuromodulator. The results of this study suggest that TRH functions as a modulator of the pituitary activity in salmonids and that TRH is used as a transmitter or modulator in the olfactory system. The presence of TRH‐positive somata in the olfactory bulb and ventral telencephalon provides new insights into the comparative anatomy of the salmon telencephalon. © 1994 Wiley‐Liss, Inc.
Course of spinocerebellar axons in the ventral and lateral funiculi of the spinal cord with projections to the anterior lobe: An experimental anatomical study in the cat with retrograde tracing techniques
Authors: Xu Q. , Grant G. 
Published: January 2005

AbstractThe fiber course of the spinocerebellar tracts in the ventral and lateral funiculi of the cat spinal cord were studied by a new approach, making cordotomies at different spinal levels or lesions of the restiform body followed by injections of HRP or WGA‐HRP into the anterior cerebellar lobe. The retrogradely labeled axons showed characteristic distribution patterns related to the level and extent of the lesions. The results show the following. (1) The dorsal spinocerebellar tract (DSCT) originating ipsilaterally from the thoracic and upper lumbar segments, ascends in the dorsolateral fasciculus. It undergoes a dorsal shift during its rostral course. The tract is topically arranged and passes through the restiform body. (2) The ventral spinocerebellar tract (VSCT) arising contralaterally from lower thoracic, lumbar, and more caudal segments passes via the ventral funiculus and ascends in the ventrolateral fasciculus. This tract is also topically arranged. It makes a lateral and then a dorsal shift during its ascending course. The main portion of the VSCT enters the cerebellum via the superior cerebellar peduncle. A minor portion originating from the sacrococcygeal region enters via the restiform body. (3) The spinocerebellar fibers originating ipsilaterally from the cervical enlargement ascend in the lateralmost part of the lateral funiculus in the area between the dorsolateral and ventrolateral fasciculi. These fibers form two groups, one passing through the restiform body, the other through the superior cerebellar peduncle. (4) The spinocerebellar fibers originating contralaterally from the central cervical nucleus pass through the ventral funiculus and ascend in the lateralmost part of the lateral funiculus, mainly in the ventrolateral fasciculus. Most of the fibers seem to pass through the superior cerebellar peduncle. © 1994 Wiley‐Liss, Inc.
A physiological and structural study of neuron types in the cochlear nucleus. II. Neuron types and their structural correlation with response properties
Authors: Ostapoff E.‐Michael , Feng Jane J. , Morest D. Kent 
Published: January 2005

AbstractThe present study examined the morphological cell types of neurons labeled with intracellular horseradish peroxidase injections, many of them following electrophysiological recordings in the cochlear nucleus of gerbils and chinchillas. Most of the subdivisions and neuronal types previously described in the cat were identified in the present material, including spherical and globular bushy cells, stellate, bushy multipolar, elongate, octopus, and giant cells in the ventral cochlear nucleus, and a cartwheel cell in the dorsal cochlear nucleus. In many cases these structurally distinct neurons were correlated with their characteristic responses to stimulation by sound or intracellular injection of depolarizing current. The dendritic terminals of the elongate, antenniform, and clavate cells of the posteroventral cochlear nucleus link each of these cell types with neighboring structures in distinct patterns, which may provide a basis for differences in synaptic organization. These cell types differ from each other and from the stellate cells of the anteroventral cochlear nucleus. Despite their heterogeneous morphology, most of these neurons had a regular discharge in response to stimulation (choppers). Irregularly firing neurons (primary‐like) had very different structures, e. g., the spherical and globular bushy cells and the bushy multipolar neuron. They, too, represent a heterogeneous population. An onset neuron was identified as an octopus cell.This paper compares the morphological observations with the electrophysiological properties of different cell types reported in a companion paper (Feng. et al. [1994] J. Comp. Neurol.). Together, these findings imply that response properties may be partially independent of neuronal structure. Morphologically distinct neurons can generate similar temporal patterns in response to simple acoustic stimuli. Nevertheless, the synaptic organization of these different neuron types, including their connections, would be expected to affect or alter the cells' responses to appropriate stimuli. The possibility is raised that membrane properties and synaptic organization complement and interact with each other. © 1994 Wiley‐Liss, Inc.
Fine structure of the supramammillary nucleus of the rat: Analysis of the ultrastructural character of dopaminergic neurons
Authors: Hayakawa Tetsu , Zyo Katuya 
Published: January 2005

AbstractThe supramammillary nucleus projecting to widespread regions contains dopaminergic and non‐dopaminergic neurons. The present study provided a comprehensive electron microscopic analysis of these dopaminergic and non‐dopaminergic neurons in the supramammillary nucleus of the rat. The normal supramammillary nucleus was composed of round spindle‐shaped, small and medium‐sized neurons (12.7 × 8.0 μm, 78.0 μm2) containing a light oval nucleus with invaginated envelop, mitochondria, Golgi apparatus, lysosomes, less‐developed rough endoplasmic reticulum, and no Nissl bodies, The majority of terminals (more than 70%) in the normal neuropil were small (diameter less than 1.0 μm) and contained round vesicles forming asymmetric synaptic contacts. The terminals often contained dense‐cored vesicles.To determine the morphological features of dopaminergic neurons, we examined the ultrastructural localization of tyrosine hydroxylase (TH) immunoreactivity, which is the synthetic enzyme of dopamine, and compared TH‐immunoreactive neurons to non‐TH‐immunoreactive neurons. Their shape and size were similar. The average number of axosomatic terminals in a sectional plane was 5.0 in TH‐neurons and 2.4 in non‐TH‐neurons; the bouton covering ratio was 16.5% in the former and 8.6% in the latter. Both numbers were significantly larger in TH‐neurons than in non‐TH‐neurons. Serial ultrathin sections of these neurons revealed that the average total number of axosomatic terminals was 55.7 in the TH‐neuron and 28.4 in the non‐TH‐neuron. Characteristic lamellar bodies and subsurface cisternae were often present in TH neurons. There were no TH‐labeled terminals. These results indicate that dopaminergic neurons receive more inputs than neurons containing other neurotransmitters. © 1994 Wiley‐Liss, Inc.
Distribution of the α‐ketoglutarate dehydrogenase complex in rat brain
Authors: Calingasan Noel Y. , Baker Harriet , Sheu Kwan‐Fu Rex , Gibson Gary E. 
Published: January 2005

AbstractThe α‐ketoglutarate dehydrogenase complex (KGDHC) is a key enzyme in mitochondrial oxidation that appears critical to neurodegenerative diseases. Its activity in the brain declines in thiamine‐deficient animals, Alzheimer's disease, and Wernicke‐Korsakoff syndrome. Since selective cell populations are affected in these disorders, understanding the cellular distribution of KGDHC is important in order to define its role in the pathophysiology of these diseases. We used antisera against both bovine KGDHC and its Elk component to determine the immunocytochemical distribution of the enzyme and compare it with that of another mitochondrial enzyme, pyruvate dehydrogenase complex (PDHC) and a cholinergic neuronal marker, choline acetyltransferase (ChAT) in rat brain. Although low levels of immunoreactivity occurred in neurons, glia, and neuropil throughout the brain, some regions displayed relatively high perikaryal KGDHC enrichment. In the cerebral cortex, high immunoreactivity occurred mostly in layers III, V, and VI. The hippocampal pyramidal layer in CAl and CA2 exhibited more intense staining thah CA3. In the mammillary body, intensely labeled cells occurred in the supramammillary and lateral nuclei, while moderately stained cells predominated in the medial nucleus. The basal forebrain, basal ganglia, reticular and midline thalamic nuclei, red nucleus, pons, cranial nerve nuclei, inferior and superior colliculi, and cerebellar nuclei also contained highly immunoreactive neurons. The distribution of KGDHC overlapped with that of PDHC and colocalized to a limited extent with ChAT. These data are the first to demonstrate KGDHC immunoreactivity in discrete areas of rat brain and are vital to our understanding of selective vulnerability to metabolic insults and disease. © 1994 Wiley‐Liss, Inc.
Morphological relationships of choleragenoid horseradish peroxidase‐labeled spinal primary afferents with myenteric ganglia and mucosal associated lymphoid tissue in the cat esophagogastric junction
Authors: Clerc Nadine , Mazzia Christophe 
Published: January 2005

AbstractThe goal of the present study was to gain insight into the environmental factors influencing the activity of primary spinal afferent fibers in the different layers of the esophagogastric junction of the cat and, thus, to analyze the relationships of these afferents with various cellular components. Spinal primary, afferent fibers were selectively labeled by anterogradely transported choleragenoid horseradish peroxidase conjugate (B‐HRP). B‐HRP was injected into the thoracic dorsal root ganglion at the T8–T13 levels. 6‐Hydroxydopamine‐induced sympathectomy was performed prior to B‐HRP injection in order to prevent otherwise unavoidable labeling of sympathetic fibers in the gut wall.Numerous labeled fibers ran between, around, and within the myenteric ganglia. Others crossed the muscle layers directly and entered the mucosa, where some ran near granulocytes and around or through solitary lymphoid follicles. Labeled fibers were observed in the squamous esophageal epithelium but not in the fundic glandular epithelium.The fibers in the myenteric area are probably connected to the muscular tension receptors that have been detected by electrophysiologic techniques. This assumption is based on the observation that only a few fibers appear to terminate in muscle layers and on the fact that the myenteric area is very narrow and subject to powerful forces. Fibers in the myenteric ganglia could be involved in local efferent functions. Fibers in the mucosa could act as nociceptors and might be involved in local immunological responses. © 1994 Wiley‐Liss, Inc.
Expression of the neural cell adhesion molecule (NCAM) and polysialic acid during taste bud degeneration and regeneration
Authors: Smith David V. , Klevitsky Raisa , Akeson Richard A. , Shipley Michael T. 
Published: January 2005

AbstractTaste receptor cells are replaced throughout life, accompanied by continuing synaptogenesis between newly formed taste cells and first‐order gustatory fibers. The neural cell adhesion molecule (NCAM) is expressed by a subset of taste cells in adult rodents and appears on gustatory nerve fibers during development prior to differentiation of the taste buds. We employed antibodies against the extracellular domain of the NCAM polypeptide (mAb 3F4) and against polysialic acid (PSA) residues found on embryonic forms of NCAM (mAb 5A5) to investigate the relationship between the expression of these molecules and the innervation of taste buds in adult rats. In unoperated rats, anti‐NCAM recognized a subset of cells within the vallate taste buds and also the fibers of the glossopharyngeal (IXth) nerve, including those innervating the gustatory epithelium. Taste bud cells did not express PSA but mAb 5A5 immunoreactivity was observed on some fibers of the IXth nerve, including a few that entered the taste buds. Bilateral crush of the IXth nerve resulted in the loss of NCAM expression from the gustatory epithelium within 8 days. As IXth nerve fibers reinnervated the epithelium, NCAM expression was seen first in the nerve, followed by increased expression in the epithelium as the taste cells differentiated from their precursors. PSA expression by fibers of the IXth nerve did not return to normal until well after the regeneration of the vallate taste buds. The present results demonstrate that taste cell expression of NCAM is dependent upon innervation by the IXth nerve and that NCAM expression appears in the nerve prior to its expression in the differentiating epithelium during regeneration. The occurrence of a similar temporal sequence in the developing taste system suggests that NCAM could play a role in cell‐cell interactions that are important for the differentiation of the taste epithelium. Ongoing taste cell turnover and synaptogenesis between IXth nerve fibers and newly differentiating taste cells also requires recognition and adhesion, in which NCAM could play a role. © 1994 Wiley‐Liss, Inc.
Localisation of parvalbumin‐immunoreactive structures in primate caudate‐putamen
Authors: Bennett B. D. , Bolam J. P. 
Published: January 2005

AbstractTo investigate the morphology, distribution, and connections of parvalbumin‐containing neurones in the caudate‐putamen of primates, perfuse‐fixed sections were stained to reveal parvalbumin immunoroactivity. In agreement with previous observations, the caudate‐putamen was rich in parvalbumin‐positive neurones and neuropil. The neuropil staining was uneven such that the dense background staining was interspersed with zones of relatively weak staining. The distribution corresponded to the striosome/matrix system as defined by substance P or met‐enkephalin immunostaining in adjacent sections. Because parvalbumin‐positive neurones are present in regions known to project to the caudate‐putamen and the majority of parvalbumin‐positive terminals in the matrix formed asymmetric synapses, it is concluded that the uneven staining is probably due to afferents of the neostriatum.The morphology of the parvalbumin‐immunoreactive neurones varied between the striosomes and matrix; those in the matrix were smaller and possessed dendritic arborisations that were relatively uniform, whereas those in the striosomes were generally more extensively stained and possessed a greater variation in their dendritic branching patterns. The dendrites frequently crossed the boundary between the striosomes and matrix. A population of giant parvalbumin‐immunoreactive neurones was also observed in the putamen. Electron microscopic analysis revealed that, in addition to terminals forming asymmetric synapses, a smaller population formed symmetric synaptic specialisations and are presumed to be derived from the local parvalbumin‐immunoreactive neurones. Terminals of the latter group formed synapses with medium‐sized spiny neurones. Because parvalbumin‐positive neurones receive input from the cortex, they may transmit cortical information to spiny neurones. © 1994 Wiley‐Liss, Inc.
Expression of GAP43 mRNA in normally developing and transplanted neurons from the rat ventral mesencephalon
Authors: Clayton Gerald H. , Mahalik Thomas J. , Finger Thomas E. 
Published: January 2005

AbstractThese experiments were designed to determine whether the neuronal growth‐related protein GAP43 is expressed at high levels by neurons that collateralize extensively or have long periods of synaptogenesis. We also evaluated the effects of target availability on GAP43 expression. Dopaminergic neurons of the rat ventral mesencephalon (VM) were chosen for investigation because they undergo extensive collateralization and synaptogenesis during postnatal development. Double label in situ hybridization histochemistry (ISHH) and immunocytochemistry (ICC) were used to measure changes in GAP43 mRNA levels within tyrosine hydroxylase (TH)‐immunoreactive and ‐nonimmunoreactive neurons of the VM during postnatal development (p5‐adult). TH neurons show higher levels of GAP43 mRNA than do non‐TH neurons throughout normal postnatal development and in the adult. This result may be due to more extensive axonal arborization and synaptic remodeling on the part of TH neurons as they innervate the striatum. To test the effects of target availability on GAP43 utilization, grafts of embryonic (e15) VM were placed within previously 6‐hydroxydopamine (6‐OHDA)‐lesioned striata and allowed to develop for 10–28 days. Levels of GAP43 mRNA in grafted TH neurons were reduced at all time points. The short distance to target in the graft paradigm may shorten the overall axonal process length, resulting in lower requirements for growth‐related proteins such as GAP43. However, grafted non‐TH neurons had elevated levels of GAP43 mRNA, perhaps attributable to prolonged target seeking by neurons that have been isolated from their normal targets. © 1994 Wiley‐Liss, Inc.
Functional anatomy of the thalamus in the blind mole rat Spalax ehrenbergi: An architectonic and electrophysiologically controlled tracing study
Authors: Rehkämper Gerd , Necker Reinhold , Nevo Eviatar 
Published: January 2005

AbstractThe occipital cortex of the naturally blind mole rat, Spalax ehrenbergi, is occupied by an area of somatosensory representation. To date, no visual cortex has been identified electrophysiologically. In order to determine whether there are corresponding modifications in the thalamus, thalamocortical connections were studied with neuroanatomical tracing methods. Three different fluorescent tracers were injected under electrophysiological control into distinct cortical areas. Injections into the somatosensory head/face and hindlimb/trunk areas of representation revealed a posteromedial ventral nucleus and a posterolateral ventral nucleus, respectively. Additional somatotopic labeling was found in an area dorsomedial to the two ventral nuclei. This structure may be equivalent to the posterior nuclear complex in the laboratory rat. Injections into the auditory cortex of the mole rat resulted in labeling of the medial geniculate body. In contrast to the situation in the laboratory rat, in which a prominent dorsolateral geniculate body and a ventrolateral geniculate body assume dorsolateral positions, the somatosensory thalamus of the mole rat almost reaches the dorsolateral surface. This finding is corroborated by the results of the architectonic study, which failed to reveal a differentiated lateral geniculate body. Our observations suggest that the thalamocortical visual system in the mole rat is minute, whereas the somatosensory system is expanded. This situation fits the mode of life of this subterranean animal, for which touch is more important than vision. © 1994 Wiley‐Liss, Inc.
Distribution and morphology of sacral spinal cord neurons innervating pelvic structures in Xenopus laevis
Authors: Campbell H. Lee , Beattie Michael S. , Bresnahan Jacqueline C. 
Published: January 2005

AbstractRelatively little is known about the organization of neural input to pelvic viscera in amphibia. In this study, sacral spinal efferent neurons were labeled in Xenopus laevis frogs by application of horseradish peroxidase (HRP) to the tenth spinal nerve, to pelvic musculature, or to the pelvic nerve. DiI was applied to the pelvic nerve with similar results. Labeled spinal neurons were located in the intermediate gray or in the ventral horn. Neurons in the tenth dorsal root ganglion, but not in the spinal cord, were labeled after application of HRP or DiI to the pudendal nerve.The peripheral targets of DiI‐labeled pelvic nerve axons were the compressor cloaca muscle, cloaca, and bladder. DiI‐labeled pudendal nerve axons distributed peripherally to cloacal lip and medial thigh integument. These data suggest that the pudendal nerve in amphibians is purely sensory and that both somatic and autonomic motor axons traverse the pelvic nerve. © 1994 Wiley‐Liss, Inc.
Crustacean cardioactive peptide ‐ immunoreactive neurons in the ventral nervous system of crayfish
Authors: Trube Anke , Audehm Uwe , Dircksen Heinrich 
Published: January 2005

AbstractCrustacean cardioactive peptide‐immunoreactive neurons have been mapped in wholemount preparations and sections of the ventral nervous system of the crayfish Astacus astacus and Orconectes limosus. Based on their morphology, projection patterns, and staining characteristics, two types of contralaterally projecting neurons are individually identifiable. In both species, these neurons occur in all neuromers as apparent serial homologs. In adult specimens, one type of cell has a small, densely stained dorsal lateral perikaryon, and a descending axon, and appears to be an interneuron. Each neuromer contains a single pair of these cells. Only in maxillary ganglia, these cells may have an additional ascending projection. The other type, a neurosecretory cell, has a larger, weakly stained perikaryon and a projection to the segmental third root of the next anterior neuromer. All neuromers contain a single pair of these neurons adjacent to the interneurons except for the abdominal neuromers, which cotain two pairs of the neurosecretory cells. Central arborizations and varicose processes toward the surface of the third roots and within the perineural sheath of the ventral nerve cord arise from these neurons. Electron microscopy of granule‐ containing terminals substantiated that these newly discovered extensive neurohemal areas are release sites for the peptide. In young immature specimens, the perikarya of both neuron types do not differ in size. Additional weakly stained small perikarya occur in all neuromers of Astacus astacus. These two types of crayfish neurons and other comparable aminergic and peptidergic neurons of crayfish and lobster are differentially distributed in the ventral cord. Furthermore, comparison of similar neuron types in crab, locust, meal worm, and moth species indicates intra‐ and interphyletic structural homologies. © 1994 Wiley‐Liss, Inc.