bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative aspects of the primate posterior cingulate cortex
Authors: Armstrong Este , Zilles Karl , Schlaug Gottfried , Schleicher Axel 
Published: January 2005

AbstractCytoarchitecturally defined cortical areas of the posterior cingulate gyrus differ morphometrically among the major taxonomic divisions of primates. Prosimians and anthropoids have different laminar proportions in the isocortical regions (areas 30, 23, and 31); anthropoids have relatively larger outer main laminae and granular layers than prosimians. In the granular retrosplenial cortex (area 29), however, prosimians and anthropoids differ only in the proportion of the molecular layer to the rest of the cortex. On the other hand, the proportions of the inner and outer main laminae of area 29 differ between the infraorder divisions of Anthropoidea, the catarrhines, and the platyrrhines. The platyrrhines (New World monkeys) have apparently specialized by increasing the outer main lamina of area 29, which contains afferent and intracortical connections. Among all primates, the amount of neuropil in each cortical region changes as a function of brain weight, but within each area, the neuropil maintains a constant ratio between the outer and inner laminae. These observations suggest that neuropil ratios are conservative features in primates and that evolutionary changes more frequently involve shifts in volumetric proportions. Furthermore, the platyrrhine‐catarrhine differences in area 29 likely evolved after the prosimian‐anthropoid differences were established in the isocortical cingulate regions.
A forebrain atlas of the lizard gekko gecko
Authors: Smeets Wilhelmus J. A. J. , Hoogland Piet V. , Lohman Anthony H. M. 
Published: January 2005

AbstractAn atlas of the forebrain of the lizard Gekko gecko has been provided, which will serve as the basis for subsequent experimental tracing and immunohistochemical studies. Apart from a strongly developed medial cortex and septal area, the Tokay gecko shows all the main features of the forebrain of the lacertid‐type lizards. When its convenience as an experimental animal is also taken into account, this species seems to be very suitable for studying the limbic system in reptiles. The atlas comprises topographical reconstructions of the telencephalon and diencephalon and a series of transverse sections of which the levels have been indicated in the reconstructions. The results obtained in the Gekko are briefly compared with those found in other lizards studied.
Callosal connectivity of areas V1 and V2 in the newborn monkey
Authors: Dehay C. , Kennedy H. , Bullier J. 
Published: January 2005

AbstractThe callosal connectivity of areas V1 and V2 in the newborn monkey has been investigated with the neuroanatomical tracers wheat germ agglutinin conjugated to horseradish peroxidase and free horseradish peroxidase. In the adult, callosal projecting neurons in cortex subserving the lower parafoveal visual field were found to extend from the V1/V2 border for a distance of 1—2.5 mm into V1 and 8 mm into V2. In the newborn, the tangential extent and total number of callosal projecting neurons were the same as in the adult.Within area V1, callosal projecting neurons in the adult and newborn were limited to supragranular layers. In the adult, axon terminals of callosal projections were located in layers 4B and 5 and were exluded from layer 4C. In the newborn, axon terminals were more extensively distributed than in the adult and invaded layer 4C.In area V2, the laminar distribution and the patchy location of callosal connections in regions of high cytochrome oxidase activity were similar in the newborn and adult animals. In both newborns and adults, the patchy distribution of callosal projections persisted when the neuroanatomical tracers were injected over extensive regions of the contralateral striate and extrastriate cortex.In the adult, area V1 and V2 project contralaterally to two heterotopic sites located in the fundus of the lunate sulcus and the superior temporal sulcus. This was also found to be the case in the newborn. In the adult the terminals of these heterotopic projections were focused in layer 4. This was not the case in the newborn, where after injection limited to the contralateral V1/V2 border they were more evenly distributed among the different cortical layers Following extensive contralateral injection of tracer, terminals in cortex anterior to V2 were focused over layer 5 and the bottom of layer 4.
Innervation of extraocular muscles in the rabbit
Authors: Murphy E. H. , Garone M. , Tashayyod D. , Baker R. B. 
Published: January 2005

AbstractThe innervation of extraocular muscles in the rabbit was studied by using the methods of horseradish peroxidase (HRP) histochemistry, gross dissection, and quantitative morphology. Subdivisions of the oculomotor complex that innervate the superior rectus, inferior rectus, medial rectus, and inferior oblique and levator palpebrae are described, and our results are in agreement with previous accounts of the projections of this nucleus. Our analysis of the innervation of the lateral rectus and retractor bulbi muscles, however, differs from previous descriptions. The axons of approximately 80% of neurons in the abducens nucleus are in the VIth nerve and innervate the lateral rectus muscle, and approximately 15–20% are internuclear neurons both surrounding and intermingling with the motor neurons of the abducens nucleus. The interneurons project to the medial rectus subdivision of the contralateral oculomotor complex via the medial longitudinal fasciculus (MLF). Neurons in both the abducens and the accessory abducens nucleus innervate the retractor bulbi muscles via the VIth nerve. All neurons in the accessory abducens nucleus innervate the retractor bulbi muscles, but gross dissection revealed that the retractor bulbi is also innervated by the IIIrd nerve. The bases for differences between our data and previously published descriptions are discussed.The trochlear nucleus of the rabbit has not been previously studied by methods of axonal trbansport. The body of the nucleus, its caudal tail, the trajectories of axons entering the trochlear nerve, and soma size distributions are described. The trochlear nucleus contains approximately 900 neurons; most are motoneurons the axons of which travel in the trochlear nerve and decussate in the anterior medullary velum. Approximately 3% of trochlear motor neurons innervate the ipsilateral superior oblique muscle. Their soma size is significantly smaller than that of contralaterally projecting neurons. For comparative purposes, the innervation of extraocular muscles by the trochlear nerve was also investigated in several rodents and carnivores. In all animals studied, the percentage of trochlear neurons innervating the ipsilateral superior oblique muscle was strikingly uniform (2—4%).Gross dissection of the extraocular muscles revealed in the rabbit a muscle, innervated by the trochlear nerve, for which we propose the name “tensor trochleae.” In the rabbit, this muscle is innervated by approximately one‐third of the trochlear motor neurons. This tensor trochleae muscle slip was observed in no other mammal in which we made gross dissections, and it has only previously been described, as an anomalous muscle, in humans. It is hypothesized that its function, in the rabbit, is to retract the muscle enclosed in the trochlea during superior oblique activation.
Descending pathways to the spinal cord in the himé salmon (landlocked red salmon, oncorhynchus nerka)
Authors: Oka Yoshitaka , Satou Masahiko , Ueda Kazuo 
Published: January 2005

AbstractDistribution and morphology of the cells of origin of the descending spinal pathways and their axonal courses were studied in the himé salmon, using retrograde labelling with cobaltic lysine and horseradish peroxidase (HRP). Following application of the tracers to the cut end of the spinal cord or injection of the tracers at the 10th to 15th spinal segment, neurons mainly labelled via the axons of passage were distributed in the mesencephalon and the rhombencephalon. Mesencephalic cell groups consisted of the nucleus pretectalis, the nucleus fasciculi longitudinalis medialis, and the nucleus ruber. The former two cell groups sent their axons to the fasciculus longitudinalis medialis. The axons of the nucleus ruber formed a separate loose bundle, the “tractus rubrospinalis.” The rhombencephalic cell groups consisted of the rhombencephalic reticular formation, the Mauthner cells (one cell for each side), and the octavolateral area. The rhombencephalic reticular formation could be further subdivided into the nucleus reticularis superior, nucleus reticularis medius, and nucleus reticularis inferior. The axons of these cell groups joined the fasciculus longitudinalis medialis and the “tractus bulbospinalis.” The Mauthner cell had two main gigantic dendrites, and its giant axons formed a conspicuous fiber of Mauthner throughout the rhombencephalon down to the spinal cord. The octavolateral area could be subdivided into the nucleus vestibularis magnocellularis, nucleus tangentialis, nucleus vestibularis descendens and nucleus intermedius. The axons of the nucleus vestibularis magnocellularis and nucleus intermedius entered the fasciculus longitudinalis medialis and/or the tractus bulbospinalis. Those of the nucleus vestibularis descendens and nucleus tangentialis formed the “tractus vestibulospinalis”. The descending spinal pathways of the himé salmon were compared with those of other fishes and other vertebrates. The significance of these descending spinal pathways in the control of locomotion and sexual behavior is also discussed.
Ascending pathways from the spinal cord in the himé salmon (landlocked red salmon, oncorhynchus nerka)
Authors: Oka Yoshitaka , Satou Masahiko , Ueda Kazuo 
Published: January 2005

AbstractThe ascending pathways from the spinal cord of the himé salmon were anterogradely labelled by the cobaltic lysine method, and their courses and terminations were examined. Following application of the cobaltic lysine to the cut end of the spinal cord or injection of the cobalt at the 10th to 15th spinal segment, labelled axons were traced from the spinal cord to various regions in the rhombencephalon and the mesencephalon. The axons ascending from the dorsal funiculus gave off many terminals as they ascended to the lower medulla. This terminal area may be homologous to the nucleus funiculi dorsalis of other vertebrates, although cytoarchitectural differentiation of the area is not evident. The dorsal funicular fibers also formed some terminals in the vagus and glossopharyngeal motor nuclei and the nucleus fasciculi solitarii. The axons arising from the anterolateral funiculus ascended as the common trunk of the lemniscus spinalis. The lemniscus spinalis fibers distributed many axon terminals on their way through the lower medulla, and most probably made synaptic contacts with the peripheral dendrites of the cells of origin of the reticulospinal pathways throughtout its rostrocaudal extent. They also projected to all the medullary cranial nerve motor nuclei (V, VI, VII, IX, and X). The rostral continuation of the lemniscus spinalis fibers entered the lemniscus lateralis and gave a rostrocaudally elongated terminal area in the nucleus lateralis of the torus semicircularis. The tractus spinocerebellaris branched from the common trunk at the level of the Vth nerve entry. The tractus spinocerebellaris terminated in the granular layers of the eminentia granularis and the valvula cerebelli, and sparsely in the corpus cerebelli as well.
Differentiation and maturation of the sensory hair bundles in the fetal and postnatal vestibular receptors of the mouse: A scanning electron microscopy study
Authors: Mbiene J.‐P. , Sans A. 
Published: January 2005

AbstractBy means of scanning electron microscopy, the differentiation and maturation of sensory hair bundles have been studied in the ampullar cristae of the mouse during development from gestational day 13 (GD13) to postnatal day 10 (PD10). Two gradients of ciliary differentiation were demonstrated, one from the apex to the base and the other from the center to the periphery. The different hair bundles that appeared on the crista during the fetal period originated in an initial ciliary stage found in regions undergoing differentiation, which was visible at the apex of the crista starting on GD14. This stage of ciliary development is gradually followed by a juvenile one at GD15. Starting on GD18, the maturation of hair bundles in the central apical area differed from that in the peripheral areas and prefigured the regional specialization of the crista found in the adult stage. In the discussion, we suggest that when the vestibular epithelial cells begin to exhibit ciliary differentiation, they are simultaneously contacted by nerve fibers.
The motor complex and primary projections of the trigeminal nerve in the monitor lizard, varanus exanthematicus
Authors: Barbas‐Henry Heleen A. , Lohman Anthony H. M. 
Published: January 2005

AbstractThe sensory projections and the motor complex of the trigeminal nerve of the reptile Varanus exanthematicus were studied with the methods of anterograde degeneration and anterograde and retrograde axonal transport. The primary afferent fibers diverge in the brainstem into a short ascending and a long descending tract. The former distributes its fibers to the principal sensory trigeminal nucleus, where nerves V1, V2, and V3 are represented along a lateromedial axis. The fibers of the descending tract enter the nucleus of this tract and the reticular formation. Both in the tract and its nucleus, nerves V1, V2 and V3 occupy succesively more dorsal position. A small contingent of nerve V1 fibers course to the accessory abducens nucleus. The descending tract extends caudally into the first and second cervical segments of the spinal cord. The trigeminal motor complex consists of dorsal, ventral, and dorsomedial nuclei. The m. adductor mandibulae externus (the main jaw closer) is represented in the dorsal nucleus, predominantly in its rostral part. The muscles innervated by nerve V3 are represented in the ventral nucleus, mainly in its caudal part. All three divisions of the trigeminal nerve contain peripheral branches of the mesencephalic trigeminal system. Collaterals of the central branches of this system were traced to the ventral motor and the principal sensory trigeminal nuclei.
Development of segmental differences in the pressure mechanosensory neurons of the leech haementeria ghilianii
Authors: Loer Curtis M. , Schley Carol , Zipser Birgit , Kristan William B. 
Published: January 2005

AbstractUsing a monoclonal antibody specific for the pressure mechanosensory neurons (P cells) of the leech Haementeria ghilianii, we have examined the segmental differences between P cells in the adult nerve cord, as well as the development of these differences during embryogenesis. The standard segmental ganglion contains two pairs of P cells of about the same size and staining intensity. The sex ganglia appear to be missing the P cells that normally innervate ventral skin, and ganglia 20 and 21 have much smaller ventral P cells than most segments. The pattern of P cells in the head and tail ganglia also differs slightly from that of the standard ganglia. During embryogenesis, when the neurons are first stained by the antibody, there are two pairs of P cells of equal size in each segmental ganglion. Obvious segmental differences arise subsequently, modifying an initially identical set of cells.
Vascular atrophy in the retinal degenerative rd mouse
Authors: Blanks Janet C. , Johnson Lincoln V. 
Published: January 2005

AbstractWe have observed that the lectin Ricinus communis agglutinin I (RCA), which binds to terminal galaotose moieties, serves as a marker for vasculature in the mouse retina. The binding of fluorescein‐isothiocyanate‐conjugated RCA was used to study the development of retinal vasculature in normal mice and in rd (retinal degeneration) mutant mice, which exhibit a massive loss of photoreceptor cells during the first month of life. In the normal mouse, retinal capillaries develop in an ordered manner and are concentrated in three major zones between the inner limiting membrane and the outer plexiform layer. In the rd mouse, the vessels appear to form normally but begin to degenerate by the end of the second postnatal week. By the end of the fourth postnatal week there is approximately a 35% reduction in the total number of vascular profiles in the rd retina compared to normal littermate controls. This reduction in vascularity is temporally associated with the photoreceptor degeneration.
Identification of a subtype of cone photoreceptor, likely to be blue sensitive, in the human retina
Authors: Ahnelt Peter K. , Kolb Helga , Pflug Renate 
Published: January 2005

AbstractA minor population of cone photoreceptors (called B‐cones) can be distinguished from the major population (called R‐cones) on morphological criteria as seen by light microscopy in foveal and peripheral human retina. The B‐cones are characterized by (1) a longer inner segment projecting into subretinal space, (2) a larger‐diameter inner segment, (3) an increased staining intensity of the inner segment, and (4) a different distribution relative to the R‐cones in the cone mosaic. B‐cones occur even in the foveolar center (3–5%) and rise to a maximum (15%) in the foveolar slope. They can also be identified in peripheral retina where they form 7–10% of the total cone population. The B‐cone population follows the distribution profile postulated for the blue‐sensitive system from histochemical studies on monkeys and from psychophysical studies on humans. The B‐cones also share many of the same morphological features of the putative blue cones of the ground squirrel and monkey retinas. For these reasons we suggest that our B‐cone group is the blue cone population of the human retina.
Correcting errors in estimating neuron area caused by the position of the nucleolus
Authors: Born Donald E. , Carman Charles S. , Rubel Edwin W 
Published: January 2005

AbstractThe technique of measuring soma cross‐sectional area at the plane of the nucleolus leads to systematic errors that depend on how far the nucleolus is displaced from the center of the soma. A set of correction factors was produced based on calculations from a geometric model of the measurement process. Applying the correction factors to measurements of second‐order auditory neurons led to substantial changes in the estimated soma area.
The morphology, number, and distribution of a large population of confirmed displaced amacrine cells in the adult cat retina
Authors: Wong R. O. L. , Hughes A. 
Published: January 2005

AbstractThe presence of a large population of some 730,000 displaced amacrines is confirmed in the ganglion cell layer of the cat retina. These cells correspond to the microneurons of Hughes and Wieniawa‐Narkiewicz (Nature 284:468–470,'80) and the bar‐cells of Hughes (J. Comp. Neurol. 197:303–339, '81): a population of profiles of which the majority had previously been presumed to be glia (Stone:J. Comp. Neurol 12:337–352, '65;J. Comp. Neurol 180:753–772, '78; Hughes:J. Comp. Neurol 163:107–128, '75).A sample of such nonganglion cells was identified by Nissl criteria in an area of retina subsequently subjected to serial sectioning and electron microscopy. Such cells form synapses with other processes in the inner plexiform layer. Members of each morphological subclass were found to bear synapses. In some instances, synapses occurred both onto and from the soma and processes of a cell, which is strong evidence for their being displaced amacrines, or preferably, “amacrines of the ganglion cell layer.”In confirmation of their amacrine nature, it was established that the microneurons and bar‐cells survive optic nerve section for up to 2.5 years. Ganglion cells underwent retrograde degeneration and completely disappeared in a much shorter time. Injection of kainic acid, a neurotoxin, into an eye whose optic nerve had been cut over 2 years previously resulted in the pyknosis of all morphologically classified microneurons and bar‐cells without influence on conventional glial cells. These results further support the conclusion that microneurons and bar‐cells are neurons and that they collectively form the displaced amacrine population of the cat ganglion cell layer.The topographic distribution of the displaced amacrines resembles that of the ganglion cells in form; their density peaks at 4,500–5,000 cells mm−2in the area centralis and falls to less than 1,000 mm−2in peripheral retina. A ganglion cell distribution map based on the latest morphological criteria derived from this study confirms that there are 170,000 ganglion cells in the cat retina. Displaced amacrines form some 80% of thetotalneuron population of the cat ganglion cell layer.The large population magnitude of these confirmed displaced amacrines implies their nonectopic origin and now provides a fresh insight into the ontogeny of the cat retinal ganglion cell layer.
Mapping of neuropeptide Y‐like immunoreactivity in the feline hypothalamus and hypophysis
Authors: Leger Lucienne , Charnay Yves , Danger Jean‐Michel , Vaudry Hubert , Pelletier Georges , Dubois Paul‐Marie , Jouvet Michel 
Published: January 2005

AbstractThe distribution of neuropeptide Y (NPY) in the cat hypothalamus and hypophysis was studied with the indirect immunofluorescence technique of Coons and co‐workers (Coons, Leduc, and Connolly: J. Exp. Med. 102:49–60, 1955), which provided a detailed map of NPY‐like immunoreactive neurons. The immunolabelling was detected in cell bodies, fibers, and terminallike structures widely distributed throughout the whole hypothalamus. A large population of medium‐sized NPY‐like immunoreactive cell bodies was localized in the area of arcuate nucleus. The number of immunoreactive cell bodies visualized was dramatically increased after intracerebroventricular injections of colchicine. Numerous immunolabelled cell bodies were also visible in the median eminence and scattered in the lateral hypothalamic area. Dense plexuses of NPY‐immunoreactive fibers were observed in the arcuate nucleus, internal layer of median eminence, periventricular zone, and paraventricular nucleus. Other regions of hypothalamus displaying numerous NPY‐like immunoreactive fibers included dorsal and ventrolateral hypothalamic areas. In contrast, certain hypothalamic areas were almost devoid of NPY‐like immunoreactive fibers—namely, the mamillary bodies and suprachiasmatic nucleus. Finally, in neurohypophysis, bright immunofluorescent fibers were observed along the pituitary stalk and penetrating the neural lobe.These results suggest the widespread distribution of the NPY‐containing neuronal systems in the cat hypothalamus and hypophysis.