bluuebunny/crossref_metadata_2025_split huggingface dataset:
Anatomic connections of inferior parietal cortex (area 7) with subcortical structures related to vestibulo‐ocular function in a monkey (macaca fascicularis)
Authors: Faugier‐Grimaud S. , Ventre J. 
Published: January 2005

AbstractConnections of the posterior parietal cortex (area 7) with subcortical structures related to the vestibulo‐ocular function were studied on four macaque monkeys by using anterograde and retrograde tracer. Wheat germ agglutinin (WGA)‐horseradish peroxidase (HRP) or tritiated amino acids were injected into the posterior part of area 7, including the caudal end of the superior bank of both the superior temporal sulcus and the lateral sulcus.The posterior parietal cortex was found to be reciprocally connected with three different ipsilateral thalamic nuclei: the nucleus ventralis posterior inferior, the magnocellular part of the medial geniculate nucleus, and some intralaminar nuclei. Through these connections, area 7 might control the vestibulo‐ocular response (VOR) by modulating the ascending vestibular information. This cortical area 7 also projects to the ipsilateral intermediate and deep layers of the superior colliculus and to several ipsilateral pontine nuclei. The dorsolateral pontine nucleus is of particular interest because it is known to be related to smooth pursuit eye movements. Cortical area 7 also was seen to project to the accessory nucleus of Darkschewitsch, to all the vestibular nuclei, and to the nucleus propositus hypoglossi; the last two projections were found to be bilateral with a greater ipsilateral contribution. Efferents from posterior parietal cortex are directed to precise regions within the vestibular nuclei that are specifically involved in vestibulo‐ocular reflex, or that are in turn connected with brainstem structures implicated in smooth pursuit eye movements. These connections are consistent with the posterior parietal cortex exerting a multilevel influence on the different systems dealing with eye‐head movement coordination.
Quantitative autoradiographic mapping of serotonin 5‐HT1 and 5‐HT2 receptors and uptake sites in the neocortex of the rhesus monkey
Authors: Lidow Michael S. , Goldman‐Rakic Patricia S. , Gallager Dorothy W. , Rakic Pasko 
Published: January 2005

AbstractThe in vitro autoradiographic technique was used to characterize the distribution of serotonin 5‐HT1 and 5‐HT2 receptors and uptake sites in 11 cortical areas of frontal, parietal, and occipital lobes in the rhesus monkey; 5‐HT1 receptors were labeled with [3H]5‐HT; 5‐HT2 receptors were labeled with [3H]ketanserin; and 5‐HT uptake sites were labeled with [3H]citalopram. Five‐HT1 and 5‐HT2 receptors and 5‐HT uptake sites were found in every cortical area examined with the absolute concentration of 5‐HT1 receptors higher than that of 5‐HT2 receptors in all areas. In eight regions of prefrontal and parietal as well as in prestriate cortex, 5‐HT1 and 5‐HT2 receptors had complementary distribution profiles: 5‐HT1 receptors were concentrated in layers I and II and the upper strata of layer III, while 5‐HT2 receptors had their highest concentration throughout layers III and IV. Only the primary motor and visual cortex had receptor distributions different from that described above. Thus, in the primary visual cortex, both 5‐HT1 and 5‐HT2 receptors were found in high concentration in sublayer IVcß, though the density of 5‐HT1 receptor was also high in other subdivisions of layer IV and in layers III, V, and VI. In the primary motor cortex, both receptor subtypes were concentrated in layers I and II and the upper strata of layer III. The pattern of distribution of serotonin uptake sites did not match the patterns of distribution of either 5‐HT1 or 5‐HT2 receptors alone; rather it approximated the combined patterns of distribution of both receptor subtypes. The complementary patterns of distribution of 5‐HT1 and 5‐HT2 receptors in most areas of the monkey cerebral cortex suggest that these two receptor subtypes may make differential contributions to cortical functions.
Age changes in axon number along the cervical ventral spinal nerve roots in rats
Authors: Fraher J. P. , O'Sullivan V. R. 
Published: January 2005

AbstractAxon counts were made at two standardised levels of C7 ventral spinal nerve roots from 46 female rats representing nine ages between birth and 500 days. The objective was to provide a definitive account of proximodistal changes in axon numbers and of age changes in axon numbers both during postnatal development and at several stages during maturity. At each age there is a proximodistal increase in the numbers of axons in all categories examined (myelinated, promyelin, transitional, and fetal) between levels midway along the subarachnoid course of the root and where it is apposed to but separate from the dorsal root ganglion.During maturation and throughout maturity axon totals change similarly at both levels: After a slight increase immediately postnatum, they decline sharply between 4 and 20 days due to a marked loss of unmyelinated axons. A gradual decline in myelinated axon numbers continues to 500 days. While these changes are occurring, axon numbers in all categories show a proximodistal increase throughout. The magnitude of this increase lessens with age for all but the transitional category due to a preferential decrease in numbers distally. Though these observations do not differentiate between axon branching and looping of sensory axons into the ventral root as a cause of the proximodistal increase in numbers, they tend to support the former.At each age during maturation axon proportions at proximal and distal levels correspond well for each animal, indicating that axon segregation proceeds at related rates within each root. Age changes in axon proportions within the transitional and fetal categories indicate that the postnatal stage of axon segregation results from axon loss, rather than Schwann cell proliferation.
Synaptophysin expression during synaptogenesis in the rat cerebellar cortex
Authors: Leclerc Nicole , Beesley Philip W. , Brown Ian , Colonnier Marc , Gurd James W. , Paladino Toni , Hawkes Richard 
Published: January 2005

AbstractIn order to study the mechanisms of synaptogenesis in the rat cerebellar cortex, a library of monoclonal antibodies has been generated against proteins of the isolated synapse. One recognizes a glycosylated 38kDa protein that is concentrated in the synaptic vesicle fraction and resembles synaptophysin biochemically in its molecular weight, charge, and pattern of glycosylation. In the adult cerebellar cortex, the antisynaptophysin (mabQ155) immunoreactivity is codistributed with synapses. Immunoreactivity is strongest in the molecular layer where punctate deposits of reaction product outline the Purkinje cell dendrites. Discrete small profiles, consistent with the distribution of basket cell axon terminals, surround the Purkinje cells, and in the granular layer the synaptic glomeruli are intensely stained. There is no immunoreactivity in the white matter axon tracts. Electron microscope immunocytochemistry confirms the synaptic location of the antigen and suggests that the reaction product is associated with synaptic vesicles. Both round and flat vesicle populations are immunoreactive. Antisynaptophysin(mabQ155) has been used to follow synaptogenesis in the developing rat cerebellum. In the newborn rat (P0), despite the paucity of synapses, there is some specific immunoreactivity, especially in the subcortical white matter. Electron microscopy shows that the antigenicity is associated with vesicles within growth cones, filopodia, and immature axon profiles. During development, antisynaptophysin immunoreactivity increases progressively, along with the maturing cell populations, for both the granule cell‐Purkinje cell and the mossy fiber‐granule cell synapses. Quantitative biochemical analysis confirms the cytochemical results. These data suggest that neuronal growth cones express a synapse‐specific antigen before complete morphological synapses are present.
Central distribution of cervical primary afferents in the rat, with emphasis on proprioceptive projections to vestibular, perihypoglossal, and upper thoracic spinal nuclei
Authors: Neuhuber W. L. , Zenker W. 
Published: January 2005

AbstractThe projections of primary afferents from rostral cervical segments to the brainstem and the spinal cord of the rat were investigated by using anterograde and transganglionic transport techniques. Projections from whole spinal ganglia were compared with those from single nerves carrying only exteroceptive or proprioceptive fibers. Injections of horseradish peroxidase (HRP) or wheat germ agglutinin‐horseradish peroxidase conjugate (WGA‐HRP) were performed into dorsal root ganglia C2, C3, and C4. Free HRP was applied to the cut dorsal rami C2 and C3, greater occipital nerve, sternomastoid nerve, and to the C1/2 anastomosis, which contains afferents from suboccipital muscles and the atlanto‐occipital joint. WGA‐HRP injections into ganglia C7 and L5 were performed for comparative purposes.Injections of WGA‐HRP or free HRP into rostral cervical dorsal root ganglia and HRP application to C2 and C3 dorsal rami produced labeling in dorsal and ventral horns at the level of entrance, the central cervical nucleus, and in external and main cuneate nuclei. From axons ascending to pontine and descending to upper thoracic spinal levels, medial collaterals were distributed to medial and descending vestibular, perihypoglossal and solitary nuclei, and the intermediate zone and Clarke's nucleus dorsalis in the spinal cord. Lateral collaterals projected mainly to the trigeminal subnucleus interpolaris and to lateral spinal laminae IV and V.Results from HRP application to single peripheral nerves indicated that medial collaterals were almost exclusively proprioceptive, whereas lateral collaterals were largely exteroceptive with a contribution from suboccipital proprioceptive fibers. WGA‐HRP injections into dorsal root ganglia C7 and L5 failed to produce significant labeling within vestibular and periphypoglossal nuclei, although they demonstrated classical projection sites within the brainstem and spinal cord.The consistent collateralisation pattern of rostral cervical afferents along their whole rostrocaudal course enables them to contact a variety of precerebellar, vestibulospinal, and preoculomotor neurons. These connections reflect the well‐known significance of proprioceptice neck afferents for the control of posture, head position, and eye movements.
Thalamic input to inferior area 6 and area 4 in the macaque monkey
Authors: Matelli Massimo , Luppino Giuseppe , Fogassi Leonardo , Rizzolatti Giacomo 
Published: January 2005

AbstractRecent cytoarchitectonic, histochemical, and hodological studies in primates have shown that area 6 is formed by three main sectors: the supplementary motor area, superior area 6, which lies medial to the spur of the arcuate sulcus, and inferior area 6, which is located lateral to it. Inferior area 6 has been further subdivided into two histochemical areas: area F5, located along the inferior limb of the arcuate sulcus, and area F4, located between area F5 and area 4 (area F1).The present study traced the thalamocortical projections of inferior area 6 and the adjacent part of area 4 by injecting small amounts of WGA‐HRP in specific sectors of the agranular frontal cortex.Our data showed that each histochemical area receives a large projection from one nucleus of the ventrolateral thalamus (motor thalamus) and additional projections from other nuclei of this thalamic sector. Area F5 receives a large projection from area X of Olszewski ('52) and additional projections from the caudal part of the nucleus ventralis posterior lateralis, pars oralis (VPLo), and the nucleus ventralis lateralis, pars caudalis (VLc) (VPLo‐VLc complex). Area F4 receives a large projection from the nucleus ventralis lateralis, pars oralis (VLo), and additional projections from area X and the VPLo‐VLc complex. The rostral part of area F1 is innervated chiefly by VLo, plus smaller contributions from rostral VPLo and the VPLo‐VLc complex. The caudal part of F1 receives its greatest input from VPLo, with a small contribution from VLo. In addition, each histochemical area receives projections originating from the intralaminar thalamic nuclei, the posterior thalamus, and–for area F4 and area F5–also from the nucleus medialis dorsalis (MD).Analysis of the physiological properties of the various histochemical areas in relation to their main thalamic input showed that those cortical fields in which distal movements are predominant (area F5, caudal part of area F1) are innervated chiefly by area X and VPLo, wheras those cortical fields in which proximal movements are predominant receive their main input from VLo. Because VPLo and area X are targets of cerebellothalamic pathways, whereas VLo receives a pallidal input, we propose that the cortical fields in which distal movements are most heavily represented are mainly under the influence of the cerebellum, whereas the cortical fields in which proximal movements are most heavily represented are mainly under the influence of the basal ganglia.
Studies on the cellular architecture of the bed nuclei of the stria terminalis in the rat: I. cytoarchitecture
Authors: Ju G. , Swanson L. W. 
Published: January 2005

AbstractThe cytoarchitecture of the bed nuclei of the stria terminalis (BST) in the adult male rat was examined in the three standard planes of section, and the results were compared with the distribution of immunohistochemical staining for a variety of neuropeptides in a companion paper (Ju et al.: J. Comp. Neurol. 280:603–621, '89). It is clear that the BST is an extremely complex mass of gray matter that can be parcellated most clearly into anterior and posterior divisions, which are separated by a more‐or‐less vertical septum of fibers associated with the stria terminalis. The anterior division can be further parcellated into dorsal, lateral, and ventral areas, and each of these areas, along with the posterior division, can be thought of as containing more‐or‐less discrete nuclei embedded within a relatively undifferentiated region. Thus, we have recognized a central core in the anterodorsal area; oval, juxtacapsular, and rhomboid nuclei in the anterolateral area; and fusiform, dorsomedial, dorsolateral, magnocellular, and ventral nuclei in the anteroventral area. The most obvious cell groups in the posterior division include the principal, interfascicular, transverse, premedullary, and dorsal nuclei. Problems associated with defining the limits of the BST, and with comparing our results with the earlier literature, are discussed.
Hormonal control of neuron number in sexually dimorphic spinal nuclei of the rat: II. Development of the spinal nucleus of the bulbocavernosus in androgen‐insensitive (Tfm) rats
Authors: Sengelaub D. R. , Kurz E. M. , Jordan C. L. , Arnold A. P. 
Published: January 2005

AbstractThe spinal nucleus of the bulbocavernosus (SNB) is a sexually dimorphic motor nucleus whose development is under the control of steroid hormones. The SNB contains many more motoneurons in adult male rats than in females, and this sex difference is produced by a sexually dimorphic motoneuron death which is regulated by androgens. To study further the role of androgens in the development of sex differences in SNB motoneuron number, we examined SNB development in males with the testicular feminization mutation (Tfm) which renders them insensitive to androgens.Counts of SNB motoneurons perinatally revealed that SNB development in normal male and female King‐Holtzman rats was similar to that reported previously for Sprague‐Dawley rats; SNB motoneuron number increased from initially low levels at embryonic day 18 through the day before birth, when motoneuron numbers in both sexes were substantially higher than adult levels. After this prenatal increase, motoneuron number declined in both sexes, until by postnatal day 10 motoneuron numbers were in their adult ranges and the sex difference was fully expressed. Females lost more motoneurons than did males during this period, and this loss was due to motoneuron death as revealed by counts of degenerating cells.SNB development in King‐Holtzman Tfm males was similar to that of normal males through embryonic day 20, suggesting that androgens may not be necessary for the initial increase in motoneuron numbers in the SNB. Thereafter, SNB motoneuron numbers in Tfm males declined in a female‐typical fashion; Tfm males and normal females did not differ at any postnatal age. The incidence of degenerating cells in Tfm males over this period was like that of normal females and significantly higher than that of normal males. These results indicate that just as treatment of females with androgens during development attenuates cell death in the SNB to male‐typical levels, resulting in masculine motoneuron numbers, the Tfm male's insensitivity to androgens results in a female‐typical cell death resulting in feminine SNB motoneuron numbers.
Brainstem projections to the major respiratory neuron populations in the medulla of the cat
Authors: Smith Jeffrey C. , Morrison Debra E. , Ellenberger Howard H. , Otto Marianne R. , Feldman Jack L. 
Published: January 2005

AbstractEfferent and afferent connections of the dorsal and ventral respiratory groups in the medulla of the cat were mapped by axonal transport of wheat germ agglutinin conjugated to horseradish peroxidase. Injections of wheat germ agglutinin‐horseradish peroxidase into the dorsal respiratory group and the three principal subdivisions of the ventral respiratory group (caudal, rostral, and Bötzinger Complex) revealed extensive interconnections between these regions and with a limited number of other brainstem neuron populations. Major neuron populations with efferent projections to the regions of the dorsal and ventral respiratory groups include the parabrachial nuclear complex (medial parabrachial, lateral parabrachial, and Kölliker‐Fuse nuclei), subregions of the lateral paragigantocellular reticular nucleus, subregions of the lateral and magnocellular tegmental fields, inferior central and postpyramidal nuclei of the raphe, and sensory trigeminal nuclei. A previously unidentified neuron population with extensive efferent projections to the dorsal and ventral respiratory groups was found near the ventral surface of the rostral medulla; we refer to this group as the retrotrapezoid nucleus. The results suggest that the dorsal and ventral respiratory groups form an extensively interconnected neuronal system receiving convergent inputs from the same brainstem nuclear groups, consistent with the hypothesis that the dorsal and ventral groups are primarily sites for integration of sensory and premotor respiratory drive inputs. Neuron populations in the rostral ventrolateral medulla with projections to both the dorsal and ventral respiratory groups, particularly the retrotrapezoid nucleus and neighboring subregions of the lateral paragigantocellular reticular nucleus, are candidate sites for participation in respiratory rhythmogenesis or other critical functions of the brainstem respiratory control system such as intracranial chemoreception.
Frontal lobe connections of the superior temporal sulcus in the rhesus monkey
Authors: Seltzer Benjamin , Pandya Deepak N. 
Published: January 2005

AbstractThe frontal lobe connections of different architectonic areas of the superior temporal sulcus (STS) in the rhesus monkey were investigated with the aid of both anterograde and retrograde tracing techniques. The proisocortical area in the rostralmost STS connects with proisocortical regions on the ventral and medial surfaces of the frontal lobe. The frontal lobe projections of polymodal cortex (area TPO) in the upper bank of the STS are organized according to the rostral‐to‐caudal topography of the sulcus. Rostral TPO interconnects with ventral (areas 13, 12, 11, and 14), medial (areas 24, 32, 14, and 9), and lateral (areas 10, 12, and 46) sectors of the frontal lobe. The midportion of polymodal cortex projects to, and receives fibers from, rostral subdivisions of lateral prefrontal cortex, viz. dorsal area 46, areas 9 and 10, whereas the caudal segment of TPO has reciprocal connections with caudal subdivisions (areas 46, 8, and 6) of the lateral frontal lobe.Visual‐related zones (areas TEa and TEm) in the rostral lower bank of the STS have connectional relationships with orbitofrontal areas 11 and 12 and lateral frontal areas 46 and 8. A presumed somatic sensory‐related area in the rostral depth of the STS (area IPa) projects to orbital (areas 11 and 14) and lateral (areas 46, 10, and 12) sectors of the frontal lobe.
Brainstem afferents to the tuberomammillary nucleus in the rat brain with special reference to monoaminergic innervation
Authors: Ericson Hans , Blomqvist Anders , Köhler Christer 
Published: January 2005

AbstractMonoaminergic innervation of a histamine‐producing cell group, the tuberomammillary nucleus in the posterior hypothalamus, was investigated in the rat by light and electron microscopic immunohistochemical techniques. Immunohistochemical staining of sections of the posterior hypothalamus was demonstrated afferent fibers immunoreactive to tyrosine hydroxylase in ventral and medial subgroups of the tuberomammillary nucleus afferent fibers immunoreactive to tyrosine hydroxylase (TH), dopamine‐ßhydroxylase (DBH), phenyletanolamineNmetyltransferase (PNMT), and serotonin (5‐HT). TH‐ and DBH‐immunoreactive fibers were similar and were evenly and densely distributed throughout the tuberomammillary nucleus. Fibers stained with 5‐HT antibodies were also present throughout the tuberomammillary nucleus but exhibited the densest labeling in the dendritic layer adjacent to the glia limitans in the ventral subgroup. Innervation by PNMT‐immunoreactive axons was sparse.Electron microscopic analysis of TH−, DBH−, and 5‐HT‐immunoreactive fibers in the tuberomammillary nucleus revealed vesicle‐containing terminal boutons, which formed synapses with dendrites of varying size. Synaptic contacts with nerve cell bodies were not found.Retrograde transport of the fluorescent dye Fast Blue injected into the tuberomammillary nucleus, combined with immunofluorescent staining with anti‐TH, anti‐DBH, anti‐PNMT, and anti‐5‐HT antibodies, showed that monoaminergic input to the tuberomammillary nucleus originated mainly from the adrenergic and noradrenergic cell groups C1C3 and A1‐A2, respectively, and from the serotoninergic cell groups B5‐B9 as designated by Dahlström and Fuxe ('65). Few double‐labeled neurons were found in the nucleus locus coeruleus and the dopaminergic cell groups of the rostral brain stem.The present findings suggest that the activity of the histamine‐producing neurons of the tuberomammillary nucleus is influenced by monoaminergic neurons in the ventrolateral and dorsomedial medulla oblongata and the raphe nuclei of the rostral brainstem.