bluuebunny/crossref_metadata_2025_split huggingface dataset:
The distribution of afferent neurones in the mesencephalic nucleus of the fifth nerve in the cat
Authors: Gottlieb Sue , Taylor Anthony , Bosley Michael A. 
Published: January 2005

AbstractThe objective of this study was to examine anatomically the distribution of afferent neurones in the mesencephalic nucleus of the fifth nerve (Mes V). HRP was applied, in separate experiments, to the inferior alveolar, infraorbital, and masseter nerves, and injected into the masseter muscle and periodontal ligament. Following application of HRP to the masseter muscle and masseter nerve, labelled cells were found in the ipsilateral motor nucleus of the fifth nerve and in the ipsilateral Mes V. Labelled cells in Mes V, identified as belonging to proprioceptor afferents from jaw‐closing muscles, were distributed throughout the full extent of the nucleus. Following application of HRP to the inferior alveolar nerve, infraorbital nerve, and periodontal ligament, labelled cells were found in the ipsilateral trigeminal ganglion and Mes V, and the latter identified as belonging to periodontal receptor afferents. In contrast to the distribution of spindle afferent somata, they were restricted to the caudal region of Mes V. The differential distribution of afferent neurones within Mes V demonstrated in this study confirms previous electrophysiological findings, and its significance is considered.
Partial characterization of lectin binding sites of retinal photoreceptor outer segments and interphotoreceptor matrix
Authors: Wood John G. , Besharse Joseph C. , Napier‐Marshall Lynda 
Published: January 2005

AbstractWe have used cytochemistry together with exoglycosidase digestion and polyacrylamide gel electrophoresis to partially characterize lectin binding sites of the interphotoreceptor matrix and of photoreceptor outer segments. In order to obtain uniform access of reagents to all regions of the preparation, we have used a procedure in which plastic sections are etched with sodium ethoxide prior to cytochemical analysis. Neuraminidase pretreatment of plastic‐embedded sections of Xenopus laevis eyecups leads to a loss of wheat germ agglutinin binding and a concomitant appearance of Ricinus communis agglutinin binding to the interphotoreceptor matrix. In contrast, wheat germ agglutinin binding to the outer segments is not altered by the neuraminidase pretreatment. These results suggest that wheat germ agglutinin binding sites of interphotoreceptor matrix are sialoglyconjugates and that outer segment binding sites are not sialoglycoconjugates. Enzyme digestions followed by lectin cytochemistry of matrix polypeptides separated by polyacrylamide gel electrophoresis do not identify a likely candidate to give rise to the cytochemical staining patterns. Lectin cytochemistry of retinas from which the interphotoreceptor matrix has been extracted do not show a loss of wheat germ agglutinin binding sites to the matrix. These results suggest that the major wheat germ agglutinin binding sites in the interphotoreceptor matrix are to as yet unidentified sialoglycoconjugates.
The postnatal development of corticotrigeminal projections in the cat
Authors: Tolbert D. L. , Dunn R. C. , Vogler G. A. 
Published: January 2005

AbstractThe postnatal development of corticotrigeminal projections was studied in kittens following 3H‐amino acid injections into the face area of the primary somatosensory cortex. Corticofugal axons grow into the brainstem and form the pyramidal tract prenatally. Corticotrigeminal projections begin to develop at the end of the first postnatal week. The earliest corticotrigeminal axons grow out of the pyramidal tract caudally and project into laminae III–V of the spinal trigeminal (Vs) nucleus caudalis. During the second postnatal week, corticotrigeminal axons grow out of the pyramidal tract in a caudal to rostral sequence and project up to the ventromedial borders of Vs‐interpolaris, Vs‐oralis, and to the principal trigeminal nucleus. Corticotrigeminal axons pause at the periphery of these nuclei for 1–2 days before penetrating the trigeminal neuropil and forming terminal arborizations in a centripetal direction. Coincident with the development of cortical projections to the principal trigeminal nucleus, some of the labeled axons which were in lamina III of Vs‐caudalis project into lamina I and terminate. This sequence of development of corticotrigeminal projections closely parallels, albeit at a later time, the sequence of formation of the trigeminal nuclei, suggesting that the temporal sequence of cytogenesis of trigeminal neurons may be a factor which regulates their order of innervation by afferents.Corticotrigeminal projections develop bilaterally and, during the second postnatal week, are relatively equal in density in the ipsilateral and contralateral nuclei. Many of the ipsilateral corticotrigeminal projections are lost, however, after the second postnatal week, so that by the fourth postnatal week, corticotrigeminal projections are mainly contralateral and adultlike in their distribution. It remains to be determined whether the transience of ipsilateral corticotrigeminal projections is due to selective elimination of axon collaterals or to neuronal death.
Afferents to the ventral tegmental nucleus of gudden in the mouse, rat, and cat
Authors: Irle Eva , Sarter Martin , Guldin Wolfgang O. , Markowitsch Hans J. 
Published: January 2005

AbstractAfferents to the ventral tegmental nucleus of Gudden (VT) were investigated in mice, rats, and cats. Unilateral and bilateral injections or iontophoretical applications of horseradish peroxidase (HRP) were made into the region of the VT. The entire cerebrum was then screened for labeled neurons. Following injection situated principally within the VT, in all three species many retrogradely labeled neurons were observed in the mamillary bodies and the lateral habenular nuclei. Fewer labeled cells were observed in the prefrontal cortex, the basal forebrain, various hypothalamic nuclei, the interpeduncular nucleus, nucleus of the posterior commissure, nucleus of Darkschewitsch and interstitial nucleus of Cajal, vestibular nucleus, and nucleus praepositus hypoglossi. Scant but consistent labeling occurred in the cingular, retrosplenial, and insular cortices, within the medial forebrain bundle, fields of Forel, zona incerta, ventral tegmental area of Tsai, substantia nigra, pretectal area, periaqueductal gray, dorsal tegmental nucleus, locus ceruleus, and raphe complex. Our results show a high similarity in the distribution of afferent connections converging on the VT of mice, rats, and cats. They indicate furthermore that the VT is reached by a variety of cortical and subcortical afferents, which belong either to the limbic system or to brain stem regions related to motor, sensory, and autonomic functions. It is suggested that the VT subserves as a midbrain core structure of the limbic system, which is responsible for the transfer of motor, sensory, and autonomic informations arising within the brain stem to limbic forebrain structures.
Corticocortical connections among visual areas in the cat
Authors: Symonds Laura L. , Rosenquist Alan C. 
Published: January 2005

AbstractThe cortical interconnections of 17 visual areas in the cat were studied by making single injections through recording micropipettes of the neuroanatomical tracers 3H‐leucine and horseradish peroxidase (HRP) into the visual cortex of 40 adult animals. Coronal sections from each of the brains were analyzed for location of silver grains and HRP‐filled neurons. There are five main results: (1) all corticocortical connections among visual areas are reciprocal. (2) Each cortical visual area has a unique set of cortical connections; the cortical targets of no two cortical visual areas are identical. (3) There is a vast and complicated pattern of connections among the visual areas which implies that there are numerous parallel circuits which run through any one visual area. (4) The connections among the cortical visual areas link retinotopically similar loci and are consistent with the visuotopic maps which microelectrode recording experiments have provided. (5) The connections among visual cortical areas often originate from, or terminate in, discontinuous patches within each area; this result obtains not only for areas 17, 18, 19, and posteromedial lateral suprasylvian area (PMLS), but for at least 13 other areas as well.The data reveal many parallel pathways and suggest multiple functional circuits interconnecting visual cortical areas. Since each visual area has multiple inputs and outputs it may have multiple functions, a different one for each of the circuits of which it is a part.
Extrinsic visual and auditory cortical connections in the 4‐day‐old kitten
Authors: Cornwell Paul , Ravizza Richard , Payne Bertram 
Published: January 2005

AbstractThe major extrinsic projections to and from the visual and auditory cortical areas were examined in 4‐day‐old kittens using axonal transport of horseradish peroxidase (HRP) and/or tritiated proline. Six different afferent and seven different efferent systems were studied; all 13 were present by postnatal day 4 as revealed by either HRP, or autoradiography alone, or these two techniques combined. Topographical projections were found for the corticopetal pathways from the thalamus and claustrum and for the corticofugal pathways to the thalamus, claustrum, striatum, and tectum, as well as for the inter‐ and intrahemispheric pathways. No topographical relations were seen in projections to the cortex from the basal ganglia or the lower brainstem.The results of the present study indicate that most or all of the major extrinsic connections of the kitten's visual and auditory cortical areas are present neonatally, and that both the cells of origin and the axonal targets are arranged topographically much like those of adult cats. However, the origins of callosal projections from visual cortex are more widespread in newborn kittens than in adult cats. In addition, the laminar arrangements of the kitten's corticocortical connections differ from those of adult cats in a number of details. The results suggest that the sparing of some visual and auditory functions after neonatal lesions occurs despite the fact that the cortical areas removed have formed extrinsic connections.
The projection of the supramammillary nucleus to the hippocampal formation: An immunohistochemical and anterograde transport study with the lectin PHA‐L in the rat
Authors: Haglund Lena , Swanson Larry W. , Köhler Christer 
Published: January 2005

AbstractThe organization and possible neurotransmitter specificity of a projection from the lateral supramammillary nucleus to the hippocampal formation has been examined with immunohistochemical and axonal transport methods in the adult male rat. Experiments with the retrograde tracer true blue indicate that neurons throughout the rostrocaudal extent of the nucleus are labeled after injections in either dorsal parts of the dentate gyms and Ammon's horn, or the entorhinal area, although cells labeled by the entorhinal injections tended to occupy more ventral parts of the nucleus. Combined immunohistochemical‐retrograde transport studies showed that a small number (<5%) of cholecystokinin‐immunoreactive neurons in the caudal tip of the supramammillary nucleus project to, the hippocampal formation, as do some (5–10%) vasoactive intestinal polypeptide (VIP)‐immunoreactive neurons throughout the nucleus. Anterograde transport studies with the lectin phaseolus vulgaris leucoagglutinin (PHA‐L) indicate that fibers from the supramammillary nucleus innervate all parts of the hippocampal formation. Many varicose fibers with terminal boutons were observed in the granular and molecular layers of the dentate gyrus, throughout the molecular layer of field CA3 of Ammon's horn, and in the pyramidal layer and stratum oriens of subfield CA3a. Only scattered fibers were found in fields CA1 and CA2. Apparent terminal fields were also observed in superficial parts of the molecular layer, and deep parts of the pyramidal layer, of the subiculum, in the deepest layer of the presubiculum and parasubiculum, and in all layers of the entorhinal area.
Topographical organization of the inferior collicular projection and other connections of the ventral nucleus of the lateral lemniscus in the cat
Authors: Whitley John M. , Henkel Craig K. 
Published: January 2005

AbstractThe topographic distribution of projections from the ventral nucleus of the lateral lemniscus (VNLL) in the cat was investigated with the autoradiographic tracing method. The origin of minor projections was verified by retrograde tracing methods. Small injections of tritiated leucine were placed in restricted zones of VNLL. A major afferent fiber system to the inferior colliculus was labeled in all cases. From the injection site labeled fibers coursed through and around the nuclei of the lateral lemniscus to enter the ipsilateral inferior colliculus. Regardless of the position or small size of the injection, labeled fibers distributed widely in the inferior colliculus. Fibers ended in the central nucleus and deeper layers of the dorsal cortex in most cases. There was also labeling in the ventrolateral nucleus, but very few fibers ended as lateral as the lateral nucleus. A small number of labeled fibers passed from the inferior colliculus into the nucleus of the brachium of the inferior colliculus and adjacent tegmental areas. Some labeled fibers entered the commissure of the inferior colliculus where they were traced into the dorsal cortex and rostral pole of the inferior colliculus on the side contralateral to the injection site.Though the projections labeled in individual cases were similar in their divergent pattern within the central nucleus of the inferior colliculus, specific variations in the pattern were found. The dorsal zone of VNLL projected more heavily to the deeper layers of the dorsal cortex and an adjacent field in the central nucleus than the other zones. Dorsal injections in the middle zone of VNLL, on the other hand, labeled the medial part of the central nucleus more heavily, whereas ventral injections in the middle zone resulted in heavier lateral labeling. The ventral zone of VNLL projected heavily to a central field in the central nucleus.In addition to this major afferent system of VNLL to the inferior colliculus, a smaller descending projection was found. The descending projection ended mainly in the dorsomedial periolivary region and ventral nucleus of the trapezoid body. However, in some cases a few fibers were traced to the cochlear nuclei.Finally, we observed projections to the medial geniculate body from the dorsal and ventral zones of VNLL that ended diffusely in the medial division of the medial geniculate body. Possibly some fibers from the dorsal zone contribute to a broader projection of the lateral tegmentum to the dorsal division of the medial geniculate body.
Projections to the cardioinhibitory region of the nucleus ambiguus of rat
Authors: Stuesse Sherry L. , Fish Stephen E. 
Published: January 2005

AbstractThe nucleus ambiguus is a brainstem structure which sends projections through the vagus nerve to the viscera, primarily heart, lung, and gut. The anatomical relationship between the nucleus ambiguus and other brain structures has not been elucidated nor has the cardiac region been identified physiologically in rats. We have attempted to clarify which areas of the nucleus ambiguus are cardioinhibitory and to determine other regions of the brain which send direct projections to this physiologically identified cardiac region. Stimulating electrodes were positioned stereotaxically in the medulla of anesthetized rats. Small currents were passed through the electrodes to locate regions in the ventrolateral medulla which slowed heart rate. In each rat, the area found was small (less than 200 μm in diameter), very specific, and located in the rostral portion of the nucleus ambiguus. Micro‐quantities of horseradish peroxidase were then iontophoretically ejected into this brainstem area; 24–72 hours following the HRP injection, the rats were processed for HRP reaction product using the tetramethybenzidine method. The major brain area which sent projections to the rostral nucleus ambiguus was the ipsilateral medial subnucleus of the solitary tract. A few labeled cells were found in the ipsilateral ventrolateral subnucleus of the solitary tract, parabrachial complex, the paraventricular nucleus of the hypothalamus, and the contralateral nucleus ambiguus. Control injections in reticular areas surrounding the rostral nucleus ambiguus showed no label in the medial solitary nucleus.
A reevaluation of midbrain and diencephalic projections to the inferior olive in rat with particular reference to the rubro‐olivary pathway
Authors: Rutherford J. G. , Anderson W. A. , Gwyn D. G. 
Published: January 2005

AbstractProjections from the midbrain and caudal diencephalon to the inferior olivary nucleus (ION) in the rat were investigated by using anterograde and retrograde tracing techniques. Particular attention was directed to studying the projection from the red nucleus (RN.) to the ION.Tritiated leucine was stereotaxically injected into the RN in six animals. The injection sites and the portion of the medulla containing the ION were processed for autoradiography. In three cases, the injections were largely confined to the RN. In these instances, no terminal labeling was noted in the ION. In the other three animals, the injections spread beyond the RN to include, in one or another of the rats, such areas as the mesencephalic reticular formation (MRF) between the RN and the periaqueductal gray (PAG), the region around the fasciculus retroflexus (FR), the prerubral area, the MRF dorsolateral to the RN, or the region dorsal to the medial geniculate body. In these animals, terminal labeling was observed ipsilaterally in the ION, chiefly in the caudal one‐half of the medial accesssory olive and in the dorsal lamella and lateral bend of the principal olive.Retrograde transport of lectin‐conjugated horseradish peroxidase (WGA‐HRP) or the fluorescent dye fast blue (FB), injected into the ION, was used to localize regions in the midbrain and caudal diencephalon containing neurons which project to the inferior olive. Following WGA‐HRP injections into the ION, retrogradely labeled neurons were found in the ipsilateral ventral PAG, the MRF between the PAG and the RN, the MRF dorsolateral to the RN, and the area dorsal to the medial geniculate body. Large numbers of heavily labeled neurons were found in the area surrounding the FR. No labeled cells were noted in the RN or the nucleus of Darkschewitsch (ND). Subsequent to FB injections into the ION, fluorescent neurons were observed in the same regions which contained HRP‐labeled neurons in the experiments using the enzyme as a tracer. Additionally, very small numbers of FB‐labeled neurons were found in the RN and the ND.These results indicate that, in the rat, descending input from the midbrain and caudal diencephalon to the ION arises chiefly from a medially located column of neurons extending from the level of the rostral RN to the region of the FR. Little, if any, input to the ION is derived from the ND or RN in this species, unlike the cat, in which a substantial projection to the ION arises from the ND and the RN.
Cell death during differentiation of the retina in the mouse
Authors: Young Richard W. 
Published: January 2005

AbstractA reproducible pattern of cell death associated with differentiation of the retina in mice was analyzed quantitatively by microscopy. Cell death occurs primarily during the first 2 weeks after birth and is essentially complete by the end of the third week. Death of individual cells involves nuclear condensation and pyknosis (apoptosis), followed by phagocytosis of the cellular remains by adjacent cells or motile phagocytes. From birth through 4 days, an increasing incidence of cell death is observed among ventricular cells. Ganglion cell degeneration is prominent during the first 11 days, peaking on days 2–5. Many presumptive amacrine cells die within the inner plexiform and inner nuclear layers, particularly between 3 and 8 days. Among adjoining bipolar and Müller cells, degeneration reaches a peak at 8–11 days. On day 5, formation of the outer plexiform layer separates the rods into two groups. Rod nuclei situated on the inner side of that layer immediately move across it to enter the outer nuclear layer, but numerous cells die during nuclear migration. Sporadic death of rods continues during the following 2 weeks. Cell death associated with cell differentiation (histogenetic death) is considered to represent a normal developmental process. Possible mechanisms resulting in cell degeneration are discussed. It is suggested that genetically regulated cell death serves to fine‐tune neuronal networks during the terminal stages of development.
Glutamate‐ and GABA‐containing neurons in the mouse and rat brain, as demonstrated with a new immunocytochemical technique
Authors: Ottersen Ole P. , Storm‐Mathisen Jon 
Published: January 2005

AbstractAntisera were raised against γ‐aminobutyric acid (GABA) or glutamate (Glu) conjugated to bovine serum albumin with glutaraldehyde. After purification, these antisera reacted strongly with fixed GABA or Glu, but not significantly with other amino acids fixed with glutaraldehyde to brain macromolecules. The antisera were used to demonstrate the distributions of Glu‐like and GABA‐like immunoreactivities (Glu‐LI and GABA‐LI) in parts of the perfusion‐fixed mouse and rat brain, including the olfactory bulb, cerebral neocortex, thalamus, basal ganglia, lower brain stem, and cerebellum.The level of GABA‐LI varied widely among brain regions, thus it was very high in the globus pallidus and substantia nigra and low in the bulk of the thalamus. The GABA antisera labeled nonpyramidal neurons of the neocortex, most cells of the reticular nucleus of the thalamus, medium‐sized cells of the caudatoputamen, and stellate, basket, Golgi, and Purkinje cells of the cerebellum. The distribution of GABA‐LI closely matched that of the GABA‐synthesizing enzyme, glutamic acid decarboxylase (GAD), as revealed in immunocytochemical studies by others. However, the GABA antisera seem to be better suited than GAD antisera for demonstrating putative GABA‐ergic axons. The results suggest that GABA‐LI, as displayed by the present method, is a good marker of neurons thought to use GABA as a transmitter.Glutamate‐like immunoreactivity was much more evenly distributed among regions than GABA‐LI, but was particularly low in globus pallidus and substantia nigra and high in the cerebral cortex. Mitral cells of the olfactory bulb, pyramidal neocortical cells, and other cells assumed to use Glu or aspartate as transmitter were stained for Glu‐LI, but so also were neurons that are thought to use other transmitters, such as cells in the substantia nigra pars compacta, in the dorsal raphe nucleus, and in the brain stem motor nuclei. The Glu antisera seem to reveal the “transmitter pool” as well as the “metabolic pool” of Glu in perfusion‐fixed material.This report shows that it is possible by means of immunocytochemistry to display reliably the tissue contents of GABA and Glu in material that has been fixed by perfusion with glutaraldehyde.