bluuebunny/crossref_metadata_2025_split huggingface dataset:
Central projections of the lateral line and eighth nerves in the bowfin, Amia calva
Authors: McCormick Catherine A. 
Published: January 2005

AbstractThe first‐order connections of the anterior and posterior lateral line nerves and of the eighth nerve were determined in the bowfin, Amia calva, using experimental degeneration and anterograde HRP transport techniques. The termination sites of these nerves define a dorsal lateralis cell column and a ventral octavus cell column.The anterior and posterior lateralis nerves distribute ipsilaterally to two medullary nuclei—nucleus medialis and nucleus caudalis. Nucleus medialis comprises the rostral two‐thirds of the lateralis column and contains large, Purkinje‐like cells dorsally and polygonal, granule, and fusiform cells ventrally. Nucleus caudalis is located posterior to nucleus medialis and consists of small, granule cells. Anterior lateralis fibers terminate ventrally to ventromedially in both nucleus medialis and nucleus caudalis. Posterior lateralis fibers terminate dorsally to dorsolaterally within these two nuclei. A sparse anterior lateralis input may also be present on the dendrites of one of the nuclei within the octavus cell column, nucleus magnocellularis. In contrast, the anterior and posterior rami of the eighth nerve each terminate within four medullary nuclei which comprise the octavus cell column: the anterior, magnocellular, descending, and posterior octavus nuclei. An eighth nerve projection to the medial reticular formation is also present.Some fibers of the lateralis and eighth nerves terminate within the ipsilateral eminentia granularis of the cerebellum. Lateralis fibers distribute to approximately the lateral half of this structure with posterior lateral line fibers terminating laterally and anterior lateral line fibers terminating medially. Eighth nerve fibers distribute to the medial half of the eminentia granularis.
Morphology of the cochlear nucleus of the normal and reeler mutant mouse
Authors: Martin Michael R. 
Published: January 2005

AbstractThe morphology of the cochlear nuclei of normal and reeler mutant mice were studied in Nissl‐stained sections. The cochlear nucleus in both mice is divisible into three parts: the anteroventral, posteroventral, and dorsal nuclei. Nine cell types can be recognized in the normal mouse. In the anteroventral nucleus spherical cells occupy the rostral pole. Globular cells are located caudally and extend to the interstitial region of the anteroventral nucleus. In the posteroventral nucleus multipolar cells are located rostrally and dark‐staining cells occupy the caudal pole. Multipolar cells are also present in the anteroventral nucleus and in the deep region and molecular layer of the dorsal cochlear nucleus. The dorsal and lateral aspects of the ventral nuclei are covered by a granule cell layer. The dorsal nucleus consists of superficial molecular and pyramidal layers and a deep region. The deep region contains small and giant cells as well as multipolar cells. The pyramidal layer is made up of pyramidal cells, horizontal cells, and granule cells. Small cells are also present in the molecular layer and throughout the ventral nuclei.The dorsal cochlear nucleus of the reeler mutant mouse is disorganized and the molecular layer is reduced in thickness. The organization of the pyramidal layer is disrupted with granule cells superficial to pyramidal and horizontal cells. Cells which appear to be homologous to pyramidal cells are also present in the deep region of the dorsal nucleus. The total number of granule cells is reduced by an average of 42% over the whole nucleus and the reduction in granule cells is greatest in the granule cell cap covering the dorsal and lateral surface of the ventral cochlear nuclei. The cytoarchitecture of the ventral cochlear nucleus appears normal.
The organization of indoleamine neurons in the brain of the rhesus monkey (Macaca mulatta)
Authors: Schofield Susan P. M. , Everitt Barry J. 
Published: January 2005

AbstractThe organization of indoleamine‐containing neurons throughout the CNS of Macaca mulatta was examined with Falck‐Hillarp histofluorescnce and radioenzymatic biochemical techniques. Indoleamine‐containing cell bodies, corresponding to the serotonin‐containing groups B1 to B9, were observed within the brain stem. The pontine cell populations, however, were far more numerous than in the rat and represented caudal subpopulations of cells within the nucleus raphe dorsalis (B7) and nucleus centralis superior (B8). Additionally, the pontine indoleamine‐containing cells in M. mulatta extended laterally through the tegmentum such that they were often adjacent to catecholamine‐containing neurons of the locus coeruleus complex. Ascending indolaemine‐containing fiber bundles, similar to those defined in nonprimate mammals, were also observed within the pons and mesencephalon.Regional differences in the distribution of serotonin within hypothalamic nuclei and other forebrain regions of M. mulatta were revealed through a highly sensitive radioenzymatic assay in conjunction with microdissection. Significant concentrations of serotonin were evident in most areas, although the levels of this neurotransmitter were much lower in the median eminence region and nucleus suprachiasmaticus than in the rat. These differences may reflect variations in the control of neuroendocrine events in the two species.
Homotopic and heterotopic callosal afferents of caudal inferior parietal lobule in Macaca mulatta
Authors: Hedreen John C. , Yin Tom C. T. 
Published: January 2005

AbstractWe have examined callosal‐axon neurons giving rise to homotopic and heterotopic callosal projections to caudal inferior parietal lobule (area PG) in Macaca mulatta, identifying these neurons by means of retrograde axonal transport of horseradish peroxidase. The labeled neurons in the homotopic region occur predominantly in layers IIIB and V. A moderate number are seen also in layer VI, a smaller number in layer IV, and rare cells occur in layer II. These neurons occupy a region very similar in outline to the injection area, and though variable in density in the horizontal plane are continuously distributed in this plane.The heterotopic neurons are seen in the contralateral cingulate gyrus, continuing caudally into medial parietal cortex, in the cortex of the superior temporal and occipitotemporal sulci, in the caudal superior temporal gyrus, and in the caudal inferior parietal lobule, behind the homotopic area. These same regions on the ipsilateral side contain labeled neurons of origin of ipsilateral association projections to area PG. For other ipsilateral association regions (e.g., frontal lobe), no corresponding contralateral heterotopic labeling was found. A review of the literature on heterotopic callosal connections allows tentative generalization of this conclusion: The callosal heterotopic connections of a particular cortical area are made with regions which on the ipsilateral side have association connections with that area, though usually not with all of such regions.
Identification and distribution of retinocollicular terminals in the cat: An electron microscopic autoradiographic analysis
Authors: Behan Mary 
Published: January 2005

AbstractThe electron microscopic (EM) autoradiographic method has been used to determine the size, distribution, and ultrastructure of retinocollicular axon terminals following intraocular injection of either (3H)‐leucine or (3H)‐proline.In the contralateral colliculus, retinal terminals are most numerous in the uppermost sublamina of the superficial grey, SGS1. The mean diameter of terminals in the contralateral SGS1 and SGS2 is 1.3 μm ± 0.33, and 1.45 μm ± 0.37, respectively. The mean diameter of terminals in the deepest contralateral sublamina, SGS3 (1.85 μm ± 0.62), is significantly larger than the mean diameter of those in the contralateral SGS1 or SGS2.By contrast, the mean diameter of terminals in different sublayers of the ipsilateral superficial grey is relatively constant, ranging from 1.56 μm ± 0.45 to 1.63 μm ± 0.60. Most ipsilateral retinal terminals are located in the uppermost part of SGS2.It is postulated that there are two populations of retinal terminals in the superficial grey: a population of smaller terminals present in the contralateral SGS1 and SGS2, and a population of larger terminals present in the contralateral SGS3. Both populations appear to be present in the ipsilateral sublaminae.While all labeled retinocollicular terminals contain round vesicles and asymmetric membrane thickenings, two morphological features appear to be correlated with retinal terminal size: (1) the population of smaller retinal terminals more frequently contacts postsynaptic profiles containing scattered round vesicles; and (2) large, dense‐core vesicles are more commonly associated with the presynaptic profiles of the population of larger terminals.A comparison of these morphological findings with available physiological data (Hoffman, 1973; Fukuda and Stone, 1974; McIlwain and Lufkin, 1976 McIlwain, 1978) suggests that the smaller terminals may be those of W‐retinal ganglion cells, and the larger terminals those of Y‐retinal ganglion cells.
Connections of the ventroposterior nucleus of the thalamus with the body surface representations in cortical areas 3b and 1 of the cynomolgus macaque, (Macaca fascicularis)
Authors: Nelson R. J. , Kaas J. H. 
Published: January 2005

AbstractThe somatotopic pattern of the connections of the ventroposterior nucleus of the thalamus with the representations of the body surface in somatic cortical Areas 3b and 1 were investigated in macaque monkeys using the anatomical tracers horseradish peroxidase (HRP), and 3H‐proline. These tracers, in combination or separately, were injected into one or more cortical sites, after the skin surface capable of activating neurons at each site had been defined with microelectrode mapping methods. These injection sites were later related to the overall organizations of the two cutaneous representations as determined in more extensive mapping experiments (Nelson et al., 1980). Finally, zones of anterograde and retrograde label in the thalamus were located with reference to architectonically defined subnuclei in the ventroposterior nucleus (VP). The results led to the following conclusions. (1) Zones of cells in VP projecting to a given location in either Area 3b or 1 also receive reciprocal projections from the cortical target. (2) A given cortical location typically relates to a disc‐shaped or lamellar region in VP with the disc extending rostrocaudally and dorsoventrally, being most narrow in the mediolateral dimension. (3) The representations of the same body surface in Area 1 and Area 3b relate to the same region of VP. However, since fewer cells were generally labeled after Area 1 injections, less dense terminations are suggested from VP to Area 1 than to Area 3b. (4) VP is the major or exclusive relay of somatosensory information to the two cutaneous representations from the thalamus. Labeled neurons or zones of terminations were found outside VP in other parts of the somatosensory thalamus only when injection sites extended into cortex outside Areas 3b and 1. (5) The face, hand, limbs, and foot are represented in a mediolateral sequence of subnuclei within VP. A dorsal capping subnucleus is apparently largely devoted to the axial trunk and perhaps other hairy skin surfaces such as some parts of the proximal surfaces of the limbs. (6) While anterior and posterior surfaces of the hind limb are widely separated by the glabrous foot in the cortical representations, they appear to be represented in adjacent zones in the thalamus.
White‐matter dendrites in the upper cervical spinal cord of the adult cat: A light and electron microscopic study
Authors: Rose P. K. , Richmond F. J. R. 
Published: January 2005

AbstractThe organization and structure of dendrites penetrating into the white matter of upper cervical spinal segments have been examined by means of Golgi staining techniques, intracellular horseradish peroxidase (HRP) injections, and ultrastructural studies. The Golgi studies established that several groups of neurons located in intermediate and ventral laminae of the upper cervical spinal cord have a substantial part of their dendritic tree extending into adjacent ventral and lateral funiculi. Most dendrites in white matter showed irregular varicosities along their length. They were devoid of spines and followed relatively direct paths. In contrast, grey matter dendrites were occasionally observed with spines and complex appendages and frequently followed tortuous paths. The size and location of some Golgi stained neurons suggested that white matter dendrites might originate from neck muscle motoneurons. This possibility was confirmed using intracellular HRP injections. These studies also showed that the distribution of white matter dendrites of neck muscle motoneurons depended on the location of the motoneuron soma. White matter dendrites of neck muscle motoneurons located deep in the ventral horn projected into all regions of white matter surrounding the ventral horn. Other neck muscle motoneurons, located in the spinal accessory nucleus, had white matter dendrites largely confined to the lateral funiculus. White matter dendrites of motoneurons in the commissural nucleus were found to project across the ventral commissure into the contralateral spinal cord.Light microscopic studies of semi‐thin sections stained with toluidine blue and electron microscopic studies of thin sections revealed that white matter dendrites were confined to special regions of the white matter. These regions resembled the grey matter neuropil and contained dendrites and unmyelinated and small diameter myelinated axons. Axon terminals were also found in white matter. These terminals contained either flattened or spherical vesicles and formed synaptic contacts on white matter dendrites.White matter dendrites, by virtue of their frequency of occurrence, distribution, and type of synaptic contacts may represent a means by which descending or ascending spinal systems can influence spinal neurons without recourse to axon collaterals which terminate in grey matter.
Effect of peripheral nerve injury on receptive fields of cells in the cat spinal cord
Authors: Devor Marshall , Wall Patrick D. 
Published: January 2005

AbstractWhen the sciatic and saphenous nerves are cut and ligated in adult cats, the immediate effect is the production of a completely anesthetic foot and a region in medial lumbar dorsal horn where almost all cells have lost their natural receptive fields (RFs). Beginning at about 1 week and maturing by 4 weeks, some 40% of cells in the medial dorsal horn gain a novel RF on proximal skin, that is, upper and lower leg, thigh, lower back, or perineum. This new RF is supplied by intact proximal nerves and not by sciatic and saphenous nerve fibers that sprouted in the periphery. During the period of switching of RFs from distal to proximal skin there was no gross atrophy of dorsal horn grey matter and no Fink‐Heimer stainable degeneration of central arbors and terminals of peripherally axotomized afferents. In intact animals medial dorsal horn cells showed no sing of response to mechanical stimulation of proximal skin. RFs of some of the cells had spontaneous variations in size and sensitivity, but these were not nearly sufficient to explain the large shifts observed after chronic nerve section. Tetanic electrical stimulation of skin or peripheral nerves often caused RFs to shrink, but never to expand. Although natural stimuli of proximal skin would not excite medial dorsal horn cells in intact or acutely deafferented animals, it was found that electrical stimulation of proximal nerves did excite many of these cells, often at short latencies. In the discussion we justify our working hypothesis that the appearance of novel RFs is due to the strengthening or unmasking of normally present but ineffective afferent terminals, rather than to long‐distance sprouting of new afferent arbors within the spinal cord.
Corneal and periocular representation within the trigeminal sensory complex in the cat studied with transganglionic transport of horseradish peroxidase
Authors: Panneton W. M. , Burton H. 
Published: January 2005

AbstractThe central projections of afferent fibers from the cornea, and the infraorbital, infratrochlear, frontal, lacrimal and auriculotemporal nerves were investigated by means of the transganglionic transport of horseradish peroxidase. Afferent projections to the dorsal horn of the medulla are organized along both the rostrocaudal axis and the ventrolateral to dorsomedial margin of the medullary dorsal horn. An inverted but discontinuous facial representation exists through the rostrocaudal axis of the dorsal horn of the medulla with perioral and nasal receptive fields innervated by the infraorbital and infratrochlear nerves represented rostral to the progressively more posterior receptive fields innervated by the frontal, lacrimal and auriculotemporal nerves, respectively. The organization of the primary afferents is not uniform over the laminae of the dorsal horn of the medulla; the projections from the different nerves show the least overlap in lamina II, while overlap is most extensive in laminae I and V. The sensory projection from the cornea to the medullary dorsal horn is most dense in laminae I and II.All nerves, including those innervating the cornea, project to the interpolar, oral and principal trigeminal nuclei and are somatotopically organized. Projections to the reticular formation and the contralateral trigeminal sensory complex were not found in this study.These results support the organization of the dorsal horn of the medulla proposed by Déjerine (1914) and show that this organization is most evident for the primary afferent projections to lamina II.
An autoradiographic study of the efferent connections of the entorhinal cortex in the rat
Authors: Michael Wyss J. 
Published: January 2005

AbstractThe longer connections of the entorhinal cortex have been studied autoradiographically in a series of rats, each of which received a small injection of 3H‐amino acids in one of the various cytoarchitectonic subfields of the entorhinal cortex. The major findings can be summarized as follows. Whereas the projection of the lateral entorhinal area (LEA) to the dentate gyrus is broad in its longitudinal extent, the medial entorhinal area (MEA), and especially the ventral portion of this zone, projects in a more lamellar fashion. In the transverse plane the LEA preferentially projects to the inner (dorsal) blade of the dentate gyrus, while the MEA innervates both blades equally. Within the radial dimension, the entorhinal cortex projects to the dentate gyrus according to a medial to lateral gradient, with lateral portions of the LEA projecting along the pial surface and successively more medial portions of the entorhinal projecting closer to the granule cells. The commissural entorhinal to dentate projections are similar to the ipsilateral projections in location; however, they are considerably reduced in septotemporal extent and do not arise from cells in the ventral half of either LEA or the intermediate entorhinal area (IEA). The projection of the entorhinal cortex to Ammon's horn reflects the same longitudinal characteristics as the denate projections. An alvear input which extends only to the pyramidal cells at the CA1‐subicular junction was most noticeable at ventral hippocampal levels. Finally the extrahippocampal projections have been analyzed. These arise predominantly from cells in the LEA and project forward along the angular bundle to the piriform and periamygdaloid cortices, as well as the endopiriform nucleus, the lateral, basolateral, and cortical amygdaloid nuclei, the nucleus of the lateral olfactory tract, the olfactory tubercle, the anterior olfactory nucleus, the taenia tecta, and the indusium griseum. These extrinsic projections are to a large extent reciprocal to the major extrinsic inputs to the LEA.
Organization of corticothalamic projections from parietal cortex in cat
Authors: Robertson Richard T. , Cunningham Timothy J. 
Published: January 2005

AbstractCorticothalamic projections from areas 5a, 5b, and 7 of cat parietal cortex were studied with autoradiographic techniques. Each cortical area was identified by its cytoarchitectural characteristics and the patterns of termination were related to the thalamic nuclear groups. Injections of 3H‐leucine in cortical area 5a were associated with terminal labeling primarily in the spinal recipient zone of the ventral lateral nucleus (VLsp) and the medial division of the posterior group (POm). The corticothalamic projections of area 5a are loosely topographically organized; medial parts of 5a project heavily to rostral and lateral parts of VLsp and sparsely to POm, while lateral parts of 5a project to more medial and caudal parts of VLsp and heavily to POm. Cortical area 5b projects primarily to the rostral portions of the lateral posterior nucleus (LP). These projections also appear to be topographically organized. The part of area 5b on the marginal gyrus projects to more ventral parts of rostral LP, while area 5b on the middle suprasylvian gyrus projects to more dorsal and lateral parts of rostral LP. Cortical area 7 projects to LP and the pulvinar (Pul). Rostral parts of area 7 project heavily to dorsal and lateral parts of LP and lightly to Pul; more caudal portions of area 7 project relatively more heavily to Pul. The reticular, central lateral, and paracentral nuclei also receive projections, especially from the suprasylvian gyrus. The results are discussed with regard to putative sensory response characteristics of these cortical areas and to general thalamocortical organization.
Giant neural systems in the inner retina and optic nerve of small whales
Authors: Dawson William W. , Hawthorne Minnie N. , Jenkins Robert L. , Goldston Richard T. 
Published: January 2005

AbstractGiant neural cell systems (dendrites, cell bodies, and axons) are present among more usual structures in the retina and optic nerve of the small whale (dolphin) Tursiops truncatus retina. Giant cell body dimensions range up to 75 μm in diameter. Nuclei of the cells are frequently larger (>20 μm) than nearby ganglion, bipolar, and receptor cell bodies. The presence of the giant cell system and giant elements in the nerve fiber layer agree with the unusually broad fiber spectrum of the dolphin optic nerve where more than 6% of the axons are >15 μm in diameter. Smaller axons in the size distribution are typical of dimensions found in terrestrial mammals. The axon estimate totaled 157,000 per optic nerve. The giant cell‐axon systems of the whale retina may be a unique expression of the large ganglion cell‐axon (transient or “Y” functional unit) systems recently identified in terrestrial mammals.