bluuebunny/crossref_metadata_2025_split huggingface dataset:
Limb specific connections of the cat magnocellular red nucleus
Authors: Robinson F. R. , Houk J. C. , Gibson A. R. 
Published: January 2005

AbstractAfferent and efferent connections of the limb specific divisions of the cat magnocellular red nucleus (RNm) were traced using the bidirectional transport of wheatgerm agglutinin‐horseradish peroxidase complex (WGA‐HRP). Injection sites within forelimb or hindlimb RNm regions were identified by microelectrode recording and confirmed by the position of labeled rubrospinal terminals. Additional injections into structures that project to, or receive input from, RNm confirmed the somatotopic organization of these pathways.The forelimb region of RNm receives input from the posteriolateral part of the anterior interpositus nucleus (NIA) and the intermediate part of the posterior interpositus nucleus (NIP). The hindlimb region of RNm receives input from anteriomedial NIA and medial NIP. Terminals of NIA cells densely fill all of RNm, but terminals of NIP cells form a half shell on the medial, ventral, and posterior borders of RNm without encroaching on RNm's lateral edge or central core. Forelimb and hindlimb RNm are reciprocally connected with the caudal cuneate and gracile nuclei respectively. There is little or no input to RNm from the medial or lateral cerebellar nuclei.Forelimb RNm, which also contains a face representation, projects to the lateral reticular nucleus, cell group f of the inferior vestibular nucleus, the facial nucleus, the main sensory nucleus of the trigeminal nerve, the caudal cuneate nucleus, the parvicellular reticular formation, and cervical segments of the spinal cord. A few fibers from forelimb RNm project directly to motor neurons in the lower cervical cord. Hindlimb RNm projects to only the lateral reticular nucleus, gracile nucleus, and lower spinal segments. Forelimb and hindlimb RNm project to different regions of the lateral reticular nucleus with some overlap.
An ultrastructural analysis of the sympathetic neuromuscular junctions on arterioles of the submucosa of the guinea pig ileum
Authors: Luff Susan E. , McLachlan Elspeth M. , Hirst G. D. S. 
Published: January 2005

AbstractThe relationship of the varicosities of sympathetic postganglionic nerve terminals to the smooth muscle cells of arterioles in the submucosa of the guinea pig ileum has been investigated quantitatively by electron microscopy. Longitudinal sections were cut through arterioles about 50 m̈m in diameter after fixation in vitro or in situ under pressure. About 13% of the varicosities in individual ultrathin sections made contact with the outer surface of the smooth muscle cells. The neuromuscular junctions resembled those in skeletal muscle: the basal laminae of the axon bundle and of the smooth muscle were fused, and synaptic vesicles were accumulated close to the region of fusion. When individual varicosities were examined in serial sections, 92% and 83% in two preparations were found to form junctions of this kind. Most of the noncontacting varicosities were bare of Schwann cell toward the arteriolar surface and separated from it by > 200 nm. Almost all axon profiles contained synaptic vesicles with electron dense cores after exposure to 5‐hydroxydopamine. In electrophysiological experiments, ionophoretic application of noradrenaline to the arteriolar surface along the nerve bundles (demonstrated subsequently by fluorescence histochemistry) produced responses resembling those evoked by nerve stimulation. These anatomical and physiological data, taken together with the evidence for quantal release in this preparation (see Hirst et al., '85), suggest that neuromuscular transmission involves the rare release of a quantum of noradrenaline at discrete points on the smooth muscle membrane.
Golgi studies on the development of granule cells of the rat olfactory bulb with reference to migration in the subependymal layer
Authors: Kishi Kiyoshi 
Published: January 2005

AbstractThe morphology and the development of the cells in the subependymal layer and of granule cells of the olfactory bulb were examined by Nissl and Golgi staining in postnatal rats. The subependymal layer around the anterior lateral ventricle extends into the center of the olfactory bulb. The mitotic indexes in the subependymal layer are high at the level of the anterior horn of the lateral ventricle and very low inside the olfactory bulb during the first 3 weeks after birth. Golgi‐stained subependymal cells are classified into two main groups. One group consists of smoothly contoured bipolar cells with leading processes tipped by large growth cones and with trailing processes. They make up a majority of Golgi‐stained subependymal cells during the first 3 weeks of age, and smaller numbers of them continue to exist at 37 and 60 days. They migrate with their growth cones oriented toward the olfactory bulb from the level of the anterior lateral ventricle into the granular layer of the olfactory bulb, where they differentiate into the definitive granule cells: their somata enlarge; the leading processes elongate, branch, sprout many gemmules, and become the peripheral processes; and the trailing processes become the basal dendrites. The other group containes relatively large cells with many cytoplasmic processes that are considered to belong to the glial cell line.
Localization of preproenkephalin mRNA in the rat brain and spinal cord by in situ hybridization
Authors: Harlan Richard E. , Shivers Brenda D. , Romano Gary J. , Pfaff D. W. , Howells Richard D. 
Published: January 2005

AbstractTo determine the localization in rat brain and spinal cord of individual neurons that contain the messenger RNA coding for the opioid peptide precursor preproenkephalin, we performed in situ hybridization with a tritiated cDNA probe complementary to a protion of preproenkephalin mRNA. We observed autoradiographic signal over the cytoplasm of neurons of many regions of the central nervous system. Several types of controls indicated specificity of the labeling. Neurons containing preproenkephalin mRNA were found in the piriform cortex, ventral tenia tecta, several regions of the neocortex, nucleus accumbens, olfactory tubercle, caudate‐putamen, lateral septum, bed nucleus of the stria terminalis, diagonal band of Broca, preoptic area, amygdala (especially central nucleus, with fewer labeled neurons in all other nuclei), hippocampal formation, anterior hypothalamic nucleus, perifornical region, lateral hypothalamus, paraventricular nucleus, dorsomedial and ventromedial hypothalamic nuclei, arcuate nucleus, dorsal and ventral premamillary nuclei, medial mamillary nucleus, lateral geniculate nucleus, zona incerta, periaqueductal gray, midbrain reticular formation, ventral tegmental area of Tsai, inferior colliculus, dorsal and ventral tegmental nuclei of Gudden, dorsal and ventral parabrachial nuclei, pontine and medullary reticular formation, several portions of the raphe nuclei, nucleus of the solitary tract, nucleus of the spinal trigeminal tract (especially substantia gelatinosa), ventral and dorsal cochlear nuclei, medial and spinal vestibular nuclei, cuneate and external cuneate nuclei, gracile nucleus, superior olive, nucleus of the trapezoid body, some deep cerebellar nuclei, Golgi neurons in the cerebellum, and most laminae of the spinal cord. In most of these brain regions, the present results indicate that many more neurons contain preproenkephalin mRNA than have been appreciated previously on the basis of immunocytochemistry.
Efferent projections of the suprachiasmatic nucleus: II. Studies using retrograde transport of fluorescent dyes and simultaneous peptide immunohistochemistry in the rat
Authors: Watts Alan G. , Swanson Larry W. 
Published: January 2005

AbstractIn a previous study (Watts et al., '87) we reexamined the projections of the suprachiasmatic nucleus (SCh) with the PHA‐L method and found that they could be divided conveniently into six groups of fibers. By far the densest projection ends just dorsal to the SCh in a comma‐shaped region designated the “subparaventricular zone,” although some fibers continue on through the paraventricular nucleus of the hypothalamus to end in the overlying midline thalamus, and others continue on to end in the dorsomedial nucleus, the region around the ventromedial nucleus, and the posterior hypothalamic area. Other relatively sparse projections from the SCh were also described to the preoptic region, lateral septal nucleus, parataenial and paraventricular nuclei of the thalamus, and ventral lateral geniculate nucleus. In addition, the same method was used to show that the subparaventricular zone projects in turn massively to these same regions, as well as back to the SCh itself and to the periaqueductal gray.The present series of experiments was designed to confirm these observations with retrograde tracer injections and to investigate the cellular and possible neurotransmitter organization of the major projections from the SCh and subparaventricular zone with a combined retrograde tracer‐immunohistochemical method. For this, the distribution of neuronal cell bodies within the SCh that stain with antisera to vasopressin, vasoactive intestinal polypeptide (VIP), corticotropin‐releasing factor, bombesin, substance P, neurotensin, somatostatin, thyrotropin‐releasing hormone, and angiotensin II was described in detail first. Then the distribution of retrogradely labeled neurons that were also stained for one or another of these peptides was described after injections of true blue, or in some cases SITS, into the regions of the subparaventricular zone, the paraventricular and parataenial nuclei of the thalamus, the ventromedial nucleus, the dorsomedial nucleus, and the periaqueductal gray. The results confirm previous immunohistochemical and anterograde tracing studies and in addition indicate that cells in dorsal as well as ventral parts of the SCh project to each of the terminal fields examined, as do many cells in surrounding areas, including the subparaventricular zone. Our results also suggest that, at the very least, vasopressin‐, VIP‐, and neurotensin‐stained cells in the SCh project to the subparaventricular zone, midline thalamus, and dorsomedial nucleus, and that the vasopressin and VIP‐stained fiber systems are partially segregated at the level of the subparaventricular zone. Finally, we have shown that neuropeptide‐Y‐stained neurons in the ventral lateral geniculate nucleus (the intergeniculate leaflet) project to the same nucleus on the opposite side of the brain.
GABAergic neurons and axon terminals in the brainstem auditory nuclei of the gerbil
Authors: Roberts Rosalinda C. , Ribak Charles E. 
Published: January 2005

AbstractThe anatomical localization of glutamic acid decarboxylase (GAD), the synthesizing enzyme for GABA, was analyzed in the brainstem auditory nuclei of the adult gerbil. GAD‐positive terminals and somata were present in the cochlear nucleus, superior olivary complex, lateral lemniscus, and inferior colliculus in varying concentrations and patterns. One of the highest densities of GAD‐positive terminals is found in the superficial layers of the dorsal cochlear nucleus (DCN), whereas the ventral cochlear nucleus (VCN) has somewhat fewer terminals that are arranged in pericellular plexuses. GAD‐positive neurons occur mainly in the superficial and fusiform layers of the DCN and are scattered throughout the VCN. Within the superior olivary complex, the highest concentration of immunoreactive terminals and neurons occurs in the ventral and lateral nuclei of the trapezoid body. In contrast, the medial nucleus of the trapezoid body and the medial superior olive contain fewer GAD‐positive puncta and probably no immunoreactive somata. The lateral superior olive and superior periolivary nucleus contain a few immunoreactive puncta but a large number of immunoreactive somata. In the midbrain, the nuclei of the lateral lemniscus contain a moderate number of GAD‐positive puncta and a large number of different types of GAD‐positive neurons. The inferior colliculus also contains a heterogeneous population of labeled somata, most of which are multipolar neurons. In addition, a high concentration of immunoreactive puncta occurs in this region. These data demonstrate a diverse distribution of GAD‐positive neurons and puncta throughout the brainstem auditory nuclei and suggest that GABA might be an important neurotransmitter in the processing of auditory information.
Variability in hand surface representations in areas 3b and 1 in adult owl and squirrel monkeys
Authors: Merzenich Michael M. , Nelson Randall J. , Kaas Jon H. , Stryker Michael P. , Jenkins William M. , Zook John M. , Cynader Max S. , Schoppmann Axel 
Published: January 2005

AbstractDetailed microelectrode maps of the hand representation were derived in cortical areas 3b and 1 from a series of normal adult owl and squirrel monkeys. While overlap relationships were maintained, and all maps were internally topographic, many map features varied significantly when examined in detail. Variable features of the hand representations among different monkeys included (a) the overall shapes and sizes of hand surface representations; (b) the actual and proportional areas of representations of different skin surfaces and the cortical magnifications of representations of specific skin surfaces, which commonly varied severalfold in area 3b and manyfold in area 1; (c) the topographic relationships among skin surface representations, with skin surfaces that were represented adjacently in some monkeys represented in locations many hundreds of microns apart in others; (d) the internal orderliness of representations; (e) the completeness of representations of the dorsal hand surfaces; and (f) the skin surfaces represented along the borders of the hand representation.Owl monkey maps were, in general, internally more strictly topographic than squirrel monkey maps. In both species, area 3b was more strictly topographic and less variable than was area 1.The degree of individual variability revealed in these experiments is difficult to reconcile with the hypothesis that details of cortical maps are ontogenetically specified during a period in early life. Instead, we propose that differences in the details of cortical map structure are the consequence of individual differences in lifelong use of the hands. This conclusion is consistent with earlier studies of the consequences of peripheral nerve transection and digital amputation, which revealed that cortical maps are dynamically maintained and are alterable as a function of use or nerve injury in these monkeys (Merzenich et al., '83a, b, '84a; Merzenich, '86; Jenkins et al., '84; Jenkins and Merzenich, '87).
Demarcations of the mechanosensory projection zones in the raccoon thalamus, shown by cytochrome oxidase, acetylcholinesterase, and Nissl stains
Authors: Wiener Sidney I. , Johnson John Irwin , Ostapoff E.‐Michael 
Published: January 2005

AbstractTo determine anatomically the boundaries and internal organization of the kinesthetic and cutaneous mechanosensory regions of the ventrobasal thalamus, alternate section series from electrophysiologically mapped tissues from 14 raccoons were stained for cytochrome oxidase, myelinated fibers, acetylcholinesterase, and Nissl substance. Microelectrode tracks, along with electrolytic lesions placed as tissue markers, reveal that (1) the mechanoreceptor projection zones have higher cytochrome oxidase and lower acetylcholinesterase staining than some neighboring regions. Both these enzymatic stains reveal particularly sharp boundaries separating the mechanoresponsive region, from the lateral posterior nucleus dorsally and from the ventroposterior inferior nucleus ventrally. (2) The kinesthetic projection zone is often separated from other mechanoreceptor projections by bundles as well as laminae of myelinated fibers, similar to those separating cutaneous projections from distinct body parts. These subdivisions are particularly well marked by the cytochrome oxidase stain. The combination, in neighboring sections, of the use of the several stains adds considerably to the visible delineation of these functionally distinct regions, beyond what can be seen in Nissl‐stained sections.
Cortical and subcortical afferent connections of a posterior division of feline area 7 (Area 7p)
Authors: Olson C. R. , Lawler K. 
Published: January 2005

AbstractArea 7 of the cat, as identified cytoarchitecturally, includes cortex both on the middle suprasylvian gyrus and on the anterior lateral gyrus. The aim of the experiments reported here was to determine whether within this zone there are subdivisions with qualitatively different patterns of afferent connectivity. Deposits of distinguishable retrograde tracers were placed at 29 sites in and around area 7 of 15 cats; cortical and subcortical telencephalic structures were then scanned for retrograde labeling. Our results indicate that cortex on the anterior lateral gyrus, although often included in area 7, is indistinguishable on connectional grounds from adjacent somesthetic cortex (area 5b), Cortex with strong links to visual, oculomotor, and association areas is confined to the middle suprasylvian gyrus and the adjacent lateral bank of the lateral sulcus. We refer to this discrete, connectionally defined zone as posterior area 7 (area 7p).Area 7p receives input from visual areas 19, 20a, 20b, 21a, 21b, AMLS, ALLS, and PLLS; from frontal oculomotor cortex (areas 6m and 61); and from cortical association areas (posterior cingulate cortex, the granular insula, the posterior ectosylvian gyrus, and posterior area 35). Thalamic projections to area 7p arise from three specific nuclei (pulvinar; nucleus lateralis intermedius, pars caudalis; nucleus ventralis anterior) and from the intralaminar complex (nuclei centralis lateralis, paracentralis and centralis medialis). Neurons in a division of the claustrum immediately beneath the somatosensory and visual zones project to area 7p. Within area 7p, anterior‐posterior regional differentiation is present, as indicated by the spatial ordering of projections from cingulate and frontal cortex, the thalamus, and the claustrum.Area 7p, as delineated by connectional analysis in this study, resembles cortex of the primate inferior parietal lobule both in its location relative to other cortical districts and in its pattern of neural connectivity.
The distribution of proenkephalin‐derived peptides in the central nervous system of turtles
Authors: Reiner Anton 
Published: January 2005

AbstractThe present study was carried out to examine if peptides similar to the various opioid peptide products of mammalian proenkephalin are present in the turtle central nervous system and to determine their distribution. Antisera against several enkephalin peptides were used: (1) leucine‐enkephalin (LENK), (2) methionine‐enkephalin (MENK), (3) methionine‐enkephalin‐arg6‐phe7 (MERF), (4) methionine‐enkephalin‐arg6‐gly7‐leu8 (MERGL), (5) Peptide E (PEPE), and (6) BAM22P. Their specificity and cross‐reactivity were carefully examined. The results indicated that LENK, MENK, and MERF (or highly similar peptides) are present in the turtle central nervous system, and that a peptide showing immunological similarity to BAM22P and PEPE also appeared to be present. In contrast, MERGL did not appear to be present. The distributions of the immunoreactive labeling for LENK, MENK, MERF, BAM22P, and PEPE were indistinguishable, and double‐label studies showed that LENK, MERF, and BAM22P were colocalized within individual neurons and fibers. Although all of the above substances were observed in the same cell groups, there was some regional variation, in terms of which enkephalin peptide appeared to be most abundant.The distributions of these enkephalin peptides were very similar to those previously described in mammals and birds. Enkephalin was more abundant in the basal ganglia than in overlying telencephalic regions. Within the basal ganglia, enkephalin was present in striatal neurons and fibers and in pallidal fibers, thereby suggesting the existence of an enkephalinergic striatopallidal projection. Sensory relay nuclei of the thalamus were generally poor in enkephalinergic fibers, whereas the hypothalamus was rich in enkephalinergic neurons and fibers. Enkephalinergic neurons and fibers were present in the midbrain central gray. As is true of neurons of the nucleus spiriformis lateralis of the avian pretectum, the neurons of the homologous cell group in turtles, the dorsal nucleus of the posterior commissure of the pretectum, were found to contain enkephalin and have an enkephalinergic projection to the deep layers of the ipsilateral tectum. Enkephalinergic neurons and fibers were also abundant in the entry zones of the trigeminal nerve and dorsal root fibers of the spinal cord.The present results indicate that: (1) consistent with previously published biochemical studies (Lindberg and White, '86), proenkephalin in reptiles is similar in structure to that of mammals and, with the exception of MERGL, gives rise to similar or identical enkephalin peptides, and (2) the enkephalin peptides are found in many of the same systems of reptilian brain as mammalian and avian brain, and, therefore, may play a role in similar functions (e.g., basal ganglia motor functions) as in mammals and birds.
Identification of abducens motoneurons, accessory abducens motoneurons, and abducens internuclear neurons in the chick by retrograde transport of horseradish peroxidase
Authors: Labandeira‐Garcia J. L. , Guerra‐Seijas M. J. , Segade L. A. G. , Suarez‐Nuñez J. M. 
Published: January 2005

AbstractThe location of the motoneurons innervating the lateral rectus, pyramidalis, and quadratus muscles of the chick has been determined by application of horseradish peroxidase (HRP) to these muscles and their nerve branches, and internuclear neurons in the abducens nucleus have been identified by injection of HRP into the oculomotor nucleus. Quantitative results were obtained by means of a semiautomatic image analyzer. Lateral rectus motoneurons were observed only in the ipsilateral principal abducens nucleus, where they numbered 500–550, and quadratus and pyramidalis motoneurons only in the ipsilateral accessory abducens nucleus. The 325–375 internuclear neurons that appeared in the principal abducens nucleus contralateral to the oculomotor nucleus injected with HRP were practically confined to the rostral two thirds of the nucleus, where they tended to surround the lateral rectus motoneurons in dorsal or lateral positions, though a minority of interneurons also mingled with the motoneurons in the center or at the medial face of the nucleus. Most interneurons were small and elongated, but a minority of larger interneurons morphologically similar to the lateral rectus motoneurons were also distinguishable. The 100–110 quadratus motoneurons and the 45–55 pyramidalis motoneurons mingled in the accessory abducens nucleus were larger than the lateral rectus motoneurons and sent their axons into the ipsilateral abducens nerve.