bluuebunny/crossref_metadata_2025_split huggingface dataset:
Retinal ganglion cell terminals in the hamster superior colliculus: An ultrastructural study
Authors: Carter D. A. , Aguayo A. J. , Bray G. M. 
Published: January 2005

AbstractThe distribution, cross‐sectional area, and presynaptic and postsynaptic characteristics of retinal ganglion cell axon terminals in the superior colliculus of normal adult female Syrian hamsters were investigated by quantitative ultrastructural techniques. After an intravitreal injection of horseradish peroxidase, most labelled axon terminals were found in the stratum griseum superficiale and stratum opticum of the contralateral superior colliculus. However, a small proportion (approximately 2%) of retinal ganglion cell axon terminals were located in deeper layers of the superior colliculus between the stratum opticum and the periaqueductal grey matter. Terminals were smaller in the upper two‐thirds of the stratum griseum superficiale than in the lower one‐third of this layer, the stratum opticum, and the stratum griseum intermedium. Presynaptic characteristics such as the length and number of contacts and the postsynaptic neuronal domains (somata, dendritic spines, or shafts) contacted by retinal ganglion cell axons in the superior colliculus were similar in all layers.
Neuronal differentiation and maturation in the mouse trigeminal sensory system, in vivo and in vitro
Authors: Stainier Didier Y. R. , Gilbert Walter 
Published: January 2005

AbstractWe have isolated and characterized four monoclonal antibodies (mAbs B33, E1.9, B30, and B10) that recognize mouse trigeminal sensory neurons at specific times during development. These antibodies permit the study of neuronal differentiation, axon outgrowth, and neuronal maturation in the trigeminal sensory system. With B33, we can follow migrating neural crest and placode cells into the anlagen of the trigeminal ganglion. E1.9 immunoreactivity marks neuronal differentiation and appears in the central nervous system at embryonic day 8.5 (E8.5) and in the peripheral nervous system at E9. E1.9 and B30 show the axonal outgrowth of trigeminal sensory neurons and reveal the pioneering of the peripheral tracts by an early population of ganglionic neurons. At this stage, in the central nervous system, mesencephalic trigeminal neurons are also E1.9 and B30 positive as they migrate to their final location in the rostral metencephalon. B30 and B10 allow us to follow the maturation of these neurons. Also, in about 1% of the embryos, we identified mispositioned or misrouted trigeminal neurons. Furthermore, these biochemical markers facilitate the study of neuronal development in vitro. We find that, based on morphological and biochemical criteria, the maturation of trigeminal neurons in culture is target independent.
Embryonic development and survival of brachial motoneurons projecting to muscleless chick wings
Authors: Phelan Kevin A. , Hollyday Margaret 
Published: January 2005

AbstractThe role of muscle cells in the survival of embryonic motoneurons projecting to the developing wing was directly examined. Embryos lacking muscle in one of their wings were produced by surgically removing the embryonic precursors of muscle cells, the somites. The resulting limb lacked only muscle cells, with the derivatives of the other limb contributor, the lateral plate mesoderm, left intact. Counts of apparently healthy lateral motor column (LMC) motoneurons supplying normal wings between stages 28 and 36 showed little decline in motoneuron number until stage 34; approximately 24% of the motoneurons died between stages 34 and 36. In contrast, the number of LMC motoneurons supplying muscleless wings declined progressively from stages 28 to 36. This decline resulted in the loss of about 77% of the motoneurons present at stage 28. In addition, the LMCs supplying muscleless wings had fewer motoneurons at all stages examined than similarly staged controls; this difference ranged from 27% in the youngest cases to 75% in the older embryos. Motoneurons were lost equivalently from all rostrocaudal levels of the brachial LMC. From these studies we conclude that motoneuron survival depends on the presence of muscle cells in the developing wing. In the absence of muscle cells, motoneuron death was increased compared to normal embryos at stages prior to the onset of naturally occurring cell death.
Regenerating retinal axons of goldfish respond to a repellent guiding component on caudal tectal membranes of adult fish and embryonic chick
Authors: Vielmetter Jost , Walter Jochen , Stuermer Claudia A. O. 
Published: January 2005

AbstractOn a substrate of rostral/caudal tectal membrane stripes of adult fish, regenerating temporal retinal axons avoid the caudal membranes. Thus they behave like embryonic chick axons on chick E9 membranes. The caudal membranes of adult fish contain a repellent component that, as has previously been shown in the chick, is inactivated by the enzyme PI‐PLC. Fish axons respond not only to their own but also to the repellent component of embryonic chick membranes. Fish and more so chick E9 caudal membranes have an outgrowth reducing effect on fish axons that is also abolished by PI‐PLC treatment and is weaker on chick E16 membranes. Thus adult fish tecta express a guiding component for retinal axons related to that in the embryonic chick.
Nigropedunculopontine projection in the rat: An Anterograde tracing study with phaseolus vulgaris‐leucoagglutinin (PHA‐L)
Authors: Spann Bryan M. , Grofova Irena 
Published: January 2005

AbstractThe termination of the substantia nigra pars reticulata efferents in the nucleus tegmenti pedunculopontinus was studied in the rat by using the anterograde tracer Phaseolusvulgaris‐leucoagglutinin (PHA‐L). Both large and small injections of PHA‐L in various portions of the substantia nigra pars reticulata labeled varicose fibers in the ipsilateral and contralateral nucleus tegmenti pedunculopontinus, subnucleus dissipatus as well as in the ipsilateral nucleus tegmenti pedunculopontinus, subnucleus compactus. However, the bulk of the nigral fibers appeared to terminate in the medial two‐thirds of the ipsilateral subnucleus dissipatus of the pedunculopontine nucleus and exhibited a discrete dorsoventral topographical pattern. The terminal plexus displayed patches of uneven density, which was partly due to the numerous fiber bundles passing through the pedunculopontine nucleus, but also to an obvious preference of nigral fibers for some cells. Electron microscopic examination confirmed that nearly all of the varicosities observed in the light microscope contained synaptic vesicles and represented either terminal boutons or boutons en passant. The labeled boutons were elongated (average length: 1.5 μm) and consistently contained a prominent group of mitochondria.The results suggest that the nigral input to the nucleus tegmenti pedunculopontinus may be directed toward specific subpopulation(s) of pedunculopontine neurons and may influence not only cells in the subnucleus dissipatus, but also in the subnucleus compactus.
Prefrontostriatal connections in relation to cortical architectonic organization in rhesus monkeys
Authors: Yeterian Edward H. , Pandya Deepak N. 
Published: January 2005

AbstractPrefrontostriatal connections were investigated in rhesus monkeys using the autoradiographic technique to examine whether there are systematic relationships with regard to the architectonic organization of the prefrontal cortex. On the basis of progressive laminar elaboration, the different regions of the prefrontal cortex can be grouped into two architectonic trends. The dorsal trend, which begins in the medial proisocortical areas, can be followed through the dorsolateral prefrontal cortex, culminating in the dorsal arcuate region. The ventral trend, which originates in the orbital proisocortex, can be traced through the inferior prefrontal convexity to the ventral arcuate region. The results show that the main connections from the prefrontal cortex to the striatum are to the head and body of the caudate nucleus. These connections are topographically organized. Medial and dorsal prefrontal areas project predominantly to the dorsal and central portion of the head and body of the caudate nucleus, whereas orbital and inferior prefrontal areas are related mainly to the ventral and central portion. Moreover, prefrontostriatal connections have a medial‐lateral topography. Medial and orbital prefrontal areas project medially in the head and body of the caudate nucleus, whereas the dorsal and ventral arcuate regions project laterally, adjacent to the internal capsule. The prefrontal regions above and below the principal sulcus project mainly to the intermediate sector of the head and body of the nucleus. However, there appears to be some degree of overlap of corticostriatal projections from the dorsal and ventral prefrontal regions, as well as within each trend. Relatively minor projections are directed to the putamen as well as to the tail of the caudate nucleus from certain subregions of the prefrontal cortex. Thus the distribution of prefrontostriatal connections seems to reflect the architectonic organization of the prefrontal cortex. Possible functional aspects of prefrontostriatal connectivity are considered in the light of behavioral and physiological studies.
Sexual dimorphism of the anterior commissure and massa intermedia of the human brain
Authors: Allen Laura S. , Gorski Roger A. 
Published: January 2005

AbstractNeuroanatomical sex differences were observed in the midsagittal area of both the anterior commissure and the massa intermedia on analysis of postmortem tissue from 100 age‐matched male and female individuals. The anterior commissure, a fiber tract whose axons in primates primarily connect the two temporal lobes, was an average of 12%, or 1.17 mm2 larger in females than in males. The massa intermedia, a structure that crosses the third ventricle between the two thalami, was present in 78% of the females and 68% of the males. Among subjects with a massa intermedia, the structure was an average of 53.3% or 17.5 mm2 larger in females than in males. Inclusive of subjects with and without a massa intermedia, this structure was a mean of 76% or 16.93 mm2 greater in females than in males. These sex differences were present despite the fact that the brains of males were larger than those of females. Since a majority of subjects were adults, it is unknown when sexual differentiation occurred. Anatomical sex differences in structures that connect the two cerebral hemispheres may, in part, underlie functional sex differences in cognitive function and cerebral lateralization.
Localization and characterization of angiotensin II receptor binding sites in the human basal ganglia, thalamus, midbrain pons, and cerebellum
Authors: Allen A. M. , Paxinos G. , McKinley M. J. , Chai S. Y. , Mendelsohn F. A. O. 
Published: January 2005

AbstractAngiotensin II (Ang II) binding sites were localized in the thalamus, basal ganglia, midbrain, and pons of the human central nervous system by in vitro autoradiography, employing 125I‐[Sar1 Ile8]angiotensin II as the radioligand. High‐density binding occurs in the substantia nigra pars compacta, the interpeduncular nucleus and two of the raphe nuclei, the raphe magnus, and median raphe nucleus. Moderate densities occur in the caudate nucleus, putamen, bed nucleus of the stria terminalis, rostral linear nucleus, caudal linear nucleus, dorsal and paramedian raphe nuclei, locus coeruleus, and region of the subcoeruleus, oral dorsal paramedian nucleus, and A5/periolivary region. Low levels occur in the region between the subthalamic nucleus and the zona incerta, the mediodorsal thalamic nucleus, the central gray, the lateral and medial parabrachial nuclei, and the molecular layer of the cerebellum.The high density of Ang II receptor binding in the substantia nigra occurs over pigmented, presumably dopaminergic, neurons. The binding in this site, and in the striatum, is not observed in any of the other species we have studied. It displays similar pharmacological characteristics to the Ang II receptor binding site in other regions of the human brain.Overall we demonstrate a discrete pattern of Ang II receptor binding sites in the human brain, which shows a high correlation with the distribution observed in other mammalian species.
The rat's postero‐orbital sinus hair: I. Brainstem projections and the effect of infraorbital nerve section at different ages
Authors: Waite Phil M. E. , de Permentier Patrick 
Published: January 2005

AbstractThe central terminations, in the trigeminal nucleus, of afferents from the rat's postero‐orbital (PO) sinus hair have been investigated with transganglionic transport of horseradish peroxidase (HRP) and succinic dehydrogenase (SDH) histochemistry. The normal pattern of terminations has been compared with that found after section of an adjacent nerve, the infraorbital (IO) nerve, at three ages: neonatal, 1 week old, and adult.The PO afferent fibres have three separate representations in the brainstem‐in trigeminal sensory nucleus principalis (Vp) and rostral subnucleus oralis (Vo), in trigeminal subnucleus interpolaris (Vi), and in caudal trigeminal subnucleus caudalis (Vc) and C1 dorsal horn. In coronal sections the areas of terminations were seen as oval patches lying ventrolaterally in Vp, Vo, and Vi and ventromedially in Vc and C1. Following neonatal IO nerve section the terminal areas were approximately doubled in Vp, Vo, and Vi but were unchanged in Vc and C1. IO nerve section at day 7 also caused a significant, though smaller (1.4× compared with 2.0×), increase in the terminal areas in the rostral three nuclei, without changing Vc and C1. However, no significant change in area occurred after adult IO nerve section. SDH histochemistry at 3 to 4 weeks of age showed patches of terminals on both normal and lesioned sides consistent with those seen after HRP.Previous studies have reported increased functional representation of surrounding intact skin regions, including the PO sinus hairs, after neonatal but not adult, IO nerve section. The present results show that there are concomitant anatomical changes. Like the functional results, the extent of the anatomical changes are dependent on the maturity of the rat when lesioned.
Identity of cells produced by two stages of cytogenesis in the postnatal cat retina
Authors: Rapaport David H. , Vietri Andrew J. 
Published: January 2005

AbstractCytogenesis in the postnatal cat retina was studied with the aid of 3H‐thymidine autoradiography to identify the cell classes generated. Cell proliferate in two stages, Which are separate spatially and temporally. Previous studies have shown that during Stage 1, cytogenesis occurs at high density at the ventricular surface of the retina, whereas Stage 2 occurs at low density in the inner retinal layers. At the ages studied, the progeny of Stage 1 cytogenesis are distributed in an annulus toward the margin of the retina, and those of Stage 2 occur central to the annulus, indicating that Stage 2 follows Stage 1. Cell genesis in Stage 1 appears to cease by P16; genesis in Stage 2 persists until between P21 and P30. The same cell classes (amacrine cells, bipolar cells, Müller cells, and rod photoreceptors) are generated during both Stages 1 and 2, but there are significant changes in their proportions both within and between stages. The proportion of the Stage 1 mitoses that form bipolar cells increases from 31% at P0 to 62% at P14. A corresponding decrease is observed in the proportion of rods (from 60% at P0 to 32% at P14). The proportion of cells generated during Stage 2 that become rods increases from 39% at P0 to 70% at P21, whereas the proportion of bipolar cells decreases from 50% at P0 to 23% at P21. Müller cells form a relatively constant proportion (8 to 15%) of the cells generated during both Stage 1 and 2. Thus at the end of Stage 1, mostly bipolar cells are generated; at the end of Stage 2, mostly rods are generated.
Subpopulations of GABAergic neurons containing parvalbumin, calbindin D28k, and cholecystokinin in the rat hippocampus
Authors: Gulyás A. I. , Tóth K. , Dános P. , Freund T. F. 
Published: January 2005

AbstractThe possible coexistence of calbindin D28k with parvalbumin and of calbindin D28k with cholecystokinin was studied in nonpyramidal cells of the rat dorsal hippocampal formation. Neighbouring Vibratome sections were immunostained either for calbindin D28k and parvalbumin or for calbindin D28k and cholecystokinin. The cells, halved during sectioning, were identified in both sections immunostained for different antigens. The coexistence of calbindin D28k and parvalbumin in the same neuron was rare throughout the hippocampal formation with the exception of stratum oriens of the CA1 region, where 9.6% of the parvalbumin‐immunoreactive cells also contained calbindin D28k. In stratum radiatum of the CA3 region, calbindin D28k and cholecystokinin coexisted in 12.5% and 21.2% of the calbindin D28k and cholecystokinin‐immunoreactive cells, respectively. In other regions of the hippocampal formation, the two markers coexisted in less than 5% of the cells of either type. The present results demonstrate that calbindin D28k‐, parvalbumin‐ and cholecystokinin‐containing nonpyramidal cells represent largely nonoverlapping cell populations and may thus be involved in different inhibitory circuits.
Morphology and somatotopic organisation of the central projections of afferents from tactile hairs on the hind leg of the locust
Authors: Newland Philip L. 
Published: January 2005

AbstractThe morphology and organisation of the central projections of tactile hair afferents from the hind leg of the locust, Schistocerca gregaria, were examined by staining individual hair afferents. Each tactile hair on the femur, tibia, and tarsus is innervated by a single sensory afferent, which projects to the ipsilateral half of the metathoracic ganglion. Afferents arborize in the ventralmost and lateral ventral association centres (vVAC and lVAC). The projections are organised somatotopically in a map with three axes, according to the position of the hair on the leg. First, proximo‐distal: afferents from hairs on the proximal leg segments project more anteriorly than do those from hairs on distal leg segments. Moreover, on any given segment the afferents from the more proximal hairs project more anteriorly than do the afferents from the distal hairs. Second, antero‐posterior: afferents from hairs on the posterior surface of the leg project more medially than do afferents from anterior hairs. Third, dorso‐ventral: afferents from hairs on ventral parts of the leg project more ventrally than do afferents from the dorsal hairs. The afferents from posterior and anterior hairs project to an area between the central projections from dorsal hairs and ventral hairs The position of a projection within the map is dependent upon the location of the hair on the leg and not the peripheral routes taken by the axon of its afferent to reach the ganglion.
Distribution of acetylcholinesterase in the hippocampal region of the mouse: II. Subiculum and hippocampus
Authors: Slomianka L. , Geneser F. A. 
Published: January 2005

AbstractThe distribution of acetylcholinesterase (AChE) was examined in the subiculum and hippocampus of the adult mouse (Mus musculus domesticus). A distinctly stratified AChE pattern was observed in both areas and was compared in detail with the cytoarchitectural fields and layers.In the subiculum, the lateral plexiform layer was lightly stained superficially and moderately stained at depth, where it abutted the lateral, moderately stained cell layer. Medially, a moderately stained deep plexiform layer separated the darkly stained superficial plexiform layer from the equally AChE‐intense cell layer. At depth, the subicular cell layer was delimited by a band of very high AChE activity. In regio superior of the hippocampus, AChE‐intense bands delimited the moderately stained strata moleculare, radiatum, and oriens toward the subjacent layers. In the stratum pyramidale, precipitate insinuated between the cell bodies gave a dark appearance to the deep part of the layer. The homologous strata of regio inferior appeared darker, but the relative staining intensities corresponded largely to those in regio superior. AChE activity in the layer of mossy fibers was almost absent septally but increased gradually to very high levels temporally.The AChE staining pattern, in conjunction with cytochemical and morphological evidence, strongly suggests a division of the pyramidal cell layer of the mouse and rat into superficial and deep substrata and discourages the definition of a prosubiculum in rodents. A comparative analysis of the AChE pattern reveals that: (1) in the subiculum, differences between species are observed within a generalized pattern of medial darkly staining and lateral lightly staining portions; (2) in the hippocampus, a conservation of the AChE pattern is seen in strata associated with intrinsic hippocampal connections; while (3) numerous interspecific differences are found in the stratum moleculare.
A synaptic antigen (B16) is localized in retinal synaptic ribbons
Authors: Balkema Grant W. 
Published: January 2005

AbstractThis morphological and biochemical study examines the cytoplasmic synaptic determinant recognized by a monoclonal antibody (B16). This antibody was generated by using an immunosuppression protocol that generates antibodies to relatively rare antigens. The B16 antibody labels structures in the brain that are dot‐shaped and in the retina that resemble synaptic ribbons in their location, size, developmental emergence, and biochemical composition. The antigen is apparently conserved across species as it is found in retinas from lizards, frogs, fish, birds, mice, rats, rabbits, cats, and monkeys. This paper focuses on observations in the murine retina.Labeling in the outer plexiform layer of the retina is confined to the margin between the outer plexiform layer (OPL) and the outer nuclear layer. The labeled structure resembles a semiellipse or an arc with the open end facing the OPL and the top facing the outer nuclear layer. Overall, the arc is approximately 1 μm in length and less than 0.5 μm thick. Approximately 10% of the labeled arcs occur in a proximal stratum of the OPL and form a planar cluster that resembles a flat plaque parallel to the OPL. Five to ten arcs are found in each plaque. The arcs found within the plaques are approximately 50% smaller than the larger isolated arcs. Counterstaining with peanut agglutinin (PNA), a lectin that recognizes cone photoreceptors and their associated processes, demonstrates that the plaques are associated with the cone pedicles. Animals that have a higher ratio of cones/rods than mice demonstrate a much higher ratio of plaques/isolated arcs in the OPL. The structure labeled in the inner plexiform layer resembles a short bar (0.8 μm long by < 0.5 μm wide) that is confined to the inner half of the inner plexiform layer in mice.The relative mobility (Mr) of the B16 antigen obtained from mouse retinal and brain tissue is 88 kD, as determined by SDS‐PAGE followed by Western blotting. The mouse 88 kD protein is relatively soluble (precipitates at 70% ammonium sulphate) and elutes at a pH of 7.3 from an isoelectric focusing column. It appears that the determinant recognized by the B16 antibody is a previously undescribed synaptic protein that is associated with the synaptic ribbons in photoreceptor and bipolar terminals of most vertebrate retinas.