bluuebunny/crossref_metadata_2025_split huggingface dataset:
Immunocytochemical localization of glutamate decarboxylase in rat spinal cord
Authors: McLaughlin Barbara J. , Barber Robert , Saito Kihachi , Roberts Eugene , Wu J. Y. 
Published: May 2005

AbstractThe GABA synthesizing enzyme, glutamate decarboxylase (GAD), has been localized by light and electron microscopy in the rat lumbosacral spinal cord using a peroxidase‐labeling antibody technique. The light microscopic localization shows heavy, punctate reaction product for GAD in the dorsal horn laminae I–III. Moderately heavy reaction product is also seen in the deeper dorsal horn laminae IV–VI, the medial aspect of the intermediate gray (lamina VII) and the region around the central canal (lamina X). A moderately light concentration of GAD reaction product is observed in the ventral horn, and punctate deposits of reaction product also are seen on motoneuron cell bodies.The punctate distribution of reaction product for GAD in both ventral and dorsal horns, as visualized by light microscopy, corresponds to GAD‐containing synaptic terminals seen by electron microscopy in comparable regions of the spinal gray. Many more GAD‐positive terminals are observed in dorsal horn laminae I–III than in deeper laminae IV–VI. GAD‐containing terminals in the dorsal horn are presynaptic to dendrites and cell bodies. GAD‐containing terminals presynaptic to other axon terminals are observed also, and they are more numerous in laminae II and III. In the ventral horn motor nuclei, GAD‐positive knobs are presynaptic to large and small dendrites and motoneuron cell bodies. In addition, small GAD‐containing terminals also are presynaptic to larger axonal terminals which are in turn presynaptic to motoneuron somata.The observation of GAD‐containing terminals presynaptic to dendrites and cell bodies in both dorsal and ventral horns is compatible with the evidence suggesting that GABA terminals may mediate postsynaptic inhibition of spinal interneurons and motoneurons. The additional finding of GAD‐positive terminals presynaptic to other axonal terminals in the dorsal horn and motor nuclei is consistent with the growing evidence that GABA also may be the transmitter mediating presynaptic inhibition via axo‐axonal synapses in the spinal cord.
Catecholamine distribution in feline hypothalamus
Authors: Cheung Yvonne , Sladek John R. 
Published: May 2005

AbstractCatecholamine distribution was examined in cat hypothalamus using the histochemical fluorescence technique of Falck and Hillarp. The heaviest accumulations of catecholamine‐containing varicosities were seen within the: anterior periventricular nucleus; dorsal hypothalamic area; bed nucleus of the inferior thalamic peduncle; dorsal component of the paraventricular nucleus; dorsomedial nucleus; infundibular nucleus; bed nucleus of the stria terminalis‐medial division; and supraoptic nucleus. Catecholaminergic perikarya were observed within periventricular, dorsal, and caudal hypothalamic areas as well as within the supramamillary nucleus and caudal diencephalon. Catecholamine distribution in cat hypothalamus possesses both similarities and dissimilarities in relation to distributions reported in other mammals.
Corticoseptal projections in the snakes Natrix sipedon and Thamnophis sirtalis
Authors: Ulinski Philip S. 
Published: May 2005

AbstractThe projections of the cerebral cortex upon the septum in water snakes (Natrix sipedon) and garter snakes (Thamnophis sirtalis) were studied with the Fink‐Heimer degeneration techniques. Two cortical areas send major projections to the septum. Medial cortex projects bilaterally to the dorsal portion of the precommissural septum along its full rostrocaudal extent. The ipsilateral projection is more massive than the contralateral one. Dorsal cortex projects ipsilaterally to a column within the septum which is present dorsally, caudal to the level of the anterior commissure, but shifts ventrally as the septum is followed rostrally. Lateral cortex may send a sparse projection to the ipsilateral ventral septum.
Olfactory relationships of the telencephalon and diencephalon in the rabbit. II. An autoradiographic and horseradish peroxidase study of the efferent connections of the anterior olfactory nucleus
Authors: Broadwell Richard D. 
Published: May 2005

AbstractThe efferent connections of the anterior olfactory nucleus in the female albino rabbit have been studied using the autoradiographic and horseradish peroxidase methods for tracing axonal pathways. Following a unilateral injection of 3H‐leucine into the olfactory peduncle, radioactively labeled efferent projections from the anterior olfactory nucleus were traced into all layers of the ipsilateral main olfactory bulb beneath the olfactory nerve layer and through the ipsilateral anterior limb of the anterior commissure and plexiform layer of the medial side of the cerebral hemisphere to the deep half of the plexiform (IB) and pyramidal cell (II) layers of the prepyriform cortex, the tenia tecta, and the entire surface of the olfactory tubercle. Labeled projections crossing the midline within the anterior commissure were followed to layers IB and II of the contralateral anterior prepyriform cortex and pars externa, pars lateralis, and pars dorsalis of the anterior olfactory nucleus, and through the periventricular layer of the olfactory peduncle to all layers of the main olfactory bulb beneath the olfactory nerve layer. No well‐defined labeled projection was traced to the contralateral accessory olfactory bulb. Evidence for possible anterior olfactory nucleus and/or prepyriform cortical projections to the ipsilateral paleocortical half of the claustrum, horizontal limb of the nucleus of the diagonal band, the posterior lateral hypothalamus at the level of the mammillary complex, and to the bed nucleus of the stria terminalis is discussed. Intra‐axonal retrograde transport of horseradish peroxidase from axon terminals to parent cell bodies after unilateral injection of the protein into the main olfactory bulb or anterior olfactory nucleus revealed that anterior olfactory nucleus projections to the olfactory bulbs and the contralateral anterior olfactory nucleus arise predominately from the pars externa.The autoradiographic data indicate that the anterior olfactory nucleus projects to olfactory cortical structures which also receive afferent input from the olfactory bulb and that the termination of these projections is complementary to those from the olfactory bulb.
A normally laminated afferent projection to an abnormally laminated cortex: Some olfactory connections in the reeler mouse
Authors: Devor Marshall , Caviness Verne S. , Derer Paul 
Published: May 2005

AbstractThe relative positions of pyramidal and polymorphic cell classes are inverted in the central olfactory cortical structures of the reeler mutant mouse. Each cell class is generated at the normal embryonic time. The polymorphic cells of the mutant, like those of the normal, are generated between E11–E13. The pyramidal cells are formed between E11–E16 in both. Despite the anomalous positions of their somata deep in the cortex the apical dendrites of many pyramidal cells reach and ramify at a superficial cortical level subjacent to the lateral olfactory tract. The main and accessory olfactory bulbs are cytoarchitectonically normal in the mutant and project normally upon the anterior olfactory nucleus, the olfactory tubercle, the hippocampal rudiment, the piriform cortex, the amygdaloid region and the entorhinal cortex. As in the normal animal the axons traverse layer Iα, and their terminals are concentrated in the immediately subjacent laminar zone. The rostrally directed cortico‐cortical association system of the piriform cortex projects upon the anterior olfactory nucleus in the mutant just as in the normal with a relative concentration of terminals in a lamina subjacent and complementary to the zone of termination of the lateral olfactory tract. The normal pattern of lamination of these two afferent systems in the abnormally laminated olfactory cortex of the mutant suggests that, in this system at least, the developmental mechanisms which determine relative position of neuron somata and those which govern axon trajectories and the distribution of axon terminals are largely independent.
Anatomy of the cerebral ganglion of the male Acanthocephalan, Moniliformis dubius
Authors: Dunagan T. T. , Miller Donald M. 
Published: May 2005

AbstractAn atlas of the cerebral ganglion of Moniliformis dubius has been constructed and the cells identified by number. There is a total of 88 cells, two of which are binucleate. These cells (20 and 90) are located in the frontal plane. The cell population is equally distributed between each half of the ganglion, there being 41 cells on each side with six cells centrally located between the two halves. Most cells give rise to bilateral processes and are organized in such a way that there is an outer coat of somata or cell bodies. Cell bodies predominate on the ventral surface, but the dorsal surface is more of a mixture of cell bodies and nerve processes. The core or neuropile occupies the central part of the ganglion and is the site for cross over for many cell processes which then exist from the side opposite the cell body. The cytoarchitecture of these cells varies considerably. Most have a large round nucleus with well defined nucleoli.
Functional localization and cortical architecture in the nine‐banded armadillo (Dasypus novemcinctus mexicanus)
Authors: Royce G. James , Martin George F. , Dom Richard M. 
Published: May 2005

AbstractA functional map of the armadillo neocortex was produced by cortical stimulation and recording evoked potentials following somatic, auditory and visual stimuli. The results obtained were then correlated with the cortical architecture as revealed by Nissl, Golgi and myelin‐stained sections. Cortex rostral to the supraorbital sulcus has a wide layer IV and is mostly silent, except for a motor eye field and a part of the tongue sensory region in its caudal part. Two types of motor‐sensory cortex are present caudal to the supraorbital sulcus. Postsupraorbital I is mostly motor and has prominent pyramidal layers. Layer V is particuarly well developed and in rostral sections its superficial zone is broken up into clusters similar to the solid “barrels” seen in layer IV of other species. Postsupraorbital II has less prominent pyramidal layers and layers II and III are organized into clusters. This region corresponds to the sensory area for the limbs and trunk and the partially overlapping (surface recordings) sensory and motor areas for head, snout and tongue. Digits and limbs are rostral to the trunk representation in both the sensory and motor “homunculi.” Even though surface recording was employed, potentials evoked by visual stimuli could only be recorded from a small caudal area with a very thin layer IV. Although striate and peristriate areas appear similar in Nissl stained preparations, they can be readily differentiated in Weil stained sections. The stellate character of neurons in layer IV of the visual cortex is particularly apparent in Golgi material. Auditory evoked surface potentials were recorded from a broad oval region in the caudal lateral cortex which has a wide layer IV and aggregates of neurons in layers II and III. A Weil stain demonstrates inner and outer bands of Baillarger in this same region. The presumptive insular cortex is electrically silent to sensory stimulation and presents as a narrow band just dorsal to the rhinal fissure with indefinite cell lamination and little myelin.
Experimental reorganization of the cerebellar cortex. V. Effects of early X‐irradiation schedules that allow or prevent the acquisition of basket cells
Authors: Altman Joseph 
Published: May 2005

AbstractIn neonate and infant rats the area of the cerebellum was irradiated with different schedules of single or multiple doses of low‐level X‐ray. One set of schedules allowed the early recovery of the external germinal layer and the differentiation of all the postnatally‐forming cell types while the other selectively prevented the acquisition of basket cells. The first schedule did not interfere with the development of normally oriented and arborizing Purkinje cells. The second schedule led to the growth of twisted and entwined stem dendrites even when, in association with the recovered granule cells, parallel fibers were present in the molecular layer together with Purkinje cell spiny branchlets. Evidence was presented that the alignment of Purkinje cell perikarya in a monolayer does not guarantee the normal growth of Purkinje cell stem dendrites which may be dependent on the presence of basket cells. The problem was discussed whether cell differentiation in the cerebellar cortex is governed by a chronological or sequential principle.
Experimental reorganization of the cerebellar cortex. VII. Effects of late X‐irradiation schedules that interfere with cell acquisition after stellate cells are formed
Authors: Altman Joseph 
Published: May 2005

AbstractIn Long‐Evans rats the area of the cerebellum was irradiated with multiple doses of low‐level X‐ray beginning on day 12 after the bulk of stellate cells were acquired. The treatment spared basket, stellate and early‐forming granule cells but led to a substantial reduction in the total granule cell population and a correlated miniaturization of the cerebellar cortex. Nevertheless most Purkinje cells had normally shaped planar dendritic arbors, with an upward directed stem dendrite, several smooth branches and a multitude of spiny branchlets. The frequent piling up of spiny branchlets near the surface was attributed to the truncation of the bed of parallel fibers by this radiation schedule.In this last paper of the series the accumulated results are summarized and evaluated. The hypothesis is offered that while the growth of the Purkinje cell perikaryon is an autonomous process, the oriented perpendicular growth of a single stem dendrite depends on the presence of basket cell axons, the outgrowth of smooth branches on the presence of stellate cell axons, and the proliferation of spiny branchlets on interaction with parallel fibers. The parallel fibers are responsible for the orthogonal, planar growth of the dendritic arbor and a hypothesis is offered about the mechanisms involved.
A comparative neuroanatomic study of retinal projections in two fishes: Astyanax hubbsi (the blind cave fish), and Astyanax mexicanus
Authors: Voneida Theodore J. , Sligar Catherine M. 
Published: May 2005

AbstractRetinofugal projections in the blind cave fish A. Hubbsi and in the highly visual A. Mexicanus were studied with both reduced silver and autoradiographic methods. Contrary to what has been reported for other teleosts, ipsilateral, as well as the generally accepted contralateral, projections were found in A. Mexicanus. Bilateral retinofugal projections were traced to the dorsolateral thalamic nucleus and area pretectalis. Contralateral projections were traced to the lateral geniculate nucleus, nucleus pretectalis, accessory optic nucleus, nucleus corticalis, nucleus opticus hypothalamicus and the superficial layers of the optic tectum (strata opticum, fibrosum and griseum superficiale, and the cellular zone of griseum centrale).Retinal efferents in the blindfish, A. Hubbsi, are sparse and totally crossed. Areas receiving a retinal projection include nucleus opticus hypothalamicus, lateral geniculate and the superficial layers of the medial third of the optic tectum. Preliminary behavioral studies are described and discussed in relation to the possible visual potential of this teleost.
Opossum somatic sensory cortex: A microelectrode mapping study
Authors: Pubols Benjamin H. , Pubols Lillian M. , Dipette Donald J. , Sheely Jay C. 
Published: May 2005

AbstractOrganization of opossum somatic sensory cortex has been investigated utilizing closely spaced microelectrode penetrations (0.25–0.5 mm apart) and delicate mechanical stimulation of body surfaces including the facial vibrissae. Results may be summarized as follows: (1) the general organization of somatic sensory cortex, as originally defined by Lende ('63a) has been confirmed; (2) a double representation of the contralateral mystacial vibrissae and rhinarium, implicit in Lende's original data, was revealed in detail, the two representations being orderly, adjacent, mirror‐images of each other; (3) units at a given cortical locus responded to deflection of between one and five mystacial vibrissae, about half responding to movement of a single vibrissa only; (4) about 40% of mystacial vibrissa units showed a directional specificity to the extent that they responded to deflections in only one or two cardinal directions; (5) units located in the medial vibrissa area showed a greater directional specificity than did units located in the lateral vibrissa area; (6) the surface area of rhinarial receptive fields was about ten times the area of first‐order rhinarial unit receptive fields (B. Pubols et al., '73); (7) representation of the contralateral forelimb, especially the ventral surface of the forepaw, is extensive, orderly, and precise; (8) representation of the contralateral hindlimb, foot, and tail is minimal, and is confined to the midline convexity; (9) the presence of a small region of bilateral representation, lateral to the regions of contralateral representation, was confirmed. It is suggested that the region of contralateral postcranial representation plus the medial rhinarium and mystacial vibrissa areas are the homologue of SmII in placental mammals, and the region of bilateral representation is homologous to SmII of placental mammals, but that the lateral vibrissa and rhinarium areas are a specialization of somatic sensory cortex unique to the Virginia opossum.
Projections of the locus coeruleus and adjacent pontine tegmentum in the cat
Authors: McBride Russell L. , Sutin Jerome 
Published: May 2005

AbstractThe projections of the locus coeruleus and adjacent pontine tegmentum have been studied using anatomical and physiological methods in the cat. Axonal trajectories were traced using either the Fink‐Heimer I method following electrolytic lesions, or the autoradiographic method after injection of tritiated proline into the nucleus. Results with both methods were similar. Axons of locus coeruleus neurons ascended ipsilaterally through the mesencephalon lateral to the medial longitudinal fasciculus, ventrolateral to the central gray. In the caudal diencephalon, the ascending fibers entered the centrum medianum‐parafascicular complex where they diverged into two fascicles; a dorsal fascicle which terminated in the intralaminar nuclei of the thalamus, and a ventral fascicle which gave off fibers to the ventrobasal complex and reticular nucleus of the thalamus while continuing ventrolaterally into the lateral hypothalamus medial to the internal capsule. Fibers of the ventral fascicle ascended in the lateral hypothalamus and zona incerta and were traced through the preoptic region into the septum. Fibers could not be consistently traced to the cerebral cortex, and were not seen at all in the cerebellum.Throughout the ascending course of the path from the locus coeruleus, axons were given off to the pretectal area, the medial and lateral geniculate nuclei, and the amygdala; fibers passed contralaterally through the posterior commissure, the midline thalamus, and the supraoptic commissure. Fibers descending from the locus coeruleus surrounded the intramedullary portion of the facial nerve and further caudally were observed ventrolateral to the hypoglossal and dorsal vagal nuclei.The axonal trajectories visualized with degeneration and autoradiographic methods followed closely those previously shown for reticular formation neurons, but were also similar to locus coeruleus projections revealed by histofluorescence methods. After injections of horseradish peroxidase into the centrum medianum‐parafascicular complex, lateral hypothalamus or preoptic region, labeled neurons were located in the locus coeruleus, nucleus subcoeruleus, and lateral parabrachial nucleus. Reticular formation neurons were not labeled. Neurons in locus coeruleus and adjacent pontine tegmentum could be antidromically activated by stimulation in the rostral midbrain or caudal diencephalon.Our data indicate that both adrenergic and non‐adrenergic neurons of the dorsolateral pontine tegmentum have similar projections.
Fine structure of synaptic vesicles in two types of nerve terminals in crayfish stretch receptor organs: Influence of fixation methods
Authors: Tisdale Ann D. , Nakajima Yasuko 
Published: May 2005

AbstractCrayfish stretch receptor organs were used. The standard procedure consisted of primary fixation with a 1.6% glutaraldehyde solution containing either buffer which was 60% hyposmotic or buffer which was isosmotic with the physiological solution )440 milliosmols(, washing with isosmotic buffer, and postfixation with an isosmotic 1% osmium tetroxide solution. Under these conditions, we encountered two types of nerve terminals; small‐vesicle terminals )SVTs( containing small elongated vesicles )300 ∼ 330 Å( and largevesicle terminals )LVTs( containing larger round vesicles )430 Å(. Their location and physiological evidence suggest that SVTs and LVTs are inhibitory and excitatory, respectively. A hyperosmotic primary fixation solution due to increased glutaraldehyde concentration gave results similar to the standard procedures, while a hyperosmotic primary fixation solution due to increased buffer concentration caused shrinkage of the nerve terminal. A hyperosmotic buffer wash produced elongation of vesicles in SVTs and LVTs, while washing with hyposmotic buffer rendered vesicles in both types round. Direct fixation with isosmotic osmium tetroxide yielded less elongated vesicles in SVTs and irregularly round vesicles in LVTs. However, under all conditions, vesicles in SVTs were smaller than those in LVTs. These results suggest that the consistent morphological difference in vesicles between SVTs and LVTs is size rather than shape, and it is important to standardize the osmolarity of primary fixation and washing solutions when discussing the differences of vesicle shape in various kinds of synapses.
Rate of climbing fiber degeneration in rabbit cerebellum following parafloccular stalk and medullopontine lesions
Authors: Mejia Hugo 
Published: May 2005

AbstractTo resolve inconsistencies in experimental studies which use reduced silver methods to detect cerebellar climbing fiber sources within the brain stem, an evaluation of the temporal course of degeneration was undertaken. The paraflocculus of the rabbit is uniquely situated within the temporal bone and connects with the corpus cerebelli via a stalk passing through a bony foramen. A unilateral electrolytic lesion deafferented the paraflocculus without disturbing blood supply or causing other damage (18 animals). Comparatively, another group of unilateral lesions was placed at the dorsolateral pontomedullary junction, adding significantly to the cortical area deafferented (12 animals). Animals of each group were killed at successively longer intervals commencing at 18 hours, and a modified Fink‐Heimer impregnation process was applied to the cerebellar cortex and opposite‐sided controls.In parafloccular lesions, degeneration was detected at 24 hours in the climbing fibers of the molecular layer. At successively longer intervals, degeneration became increasingly evident in granule layer and white matter. Subsequent to dorsolateral pontomedullary lesions, climbing fiber degeneration was first observed in the molecular layer at 24 hours and was clearly evident there at 36 hours. By 72 hours degeneration had reached the white matter, meanwhile disappearing in the molecular layer where it was first seen.Using techniques of Nauta‐Fink‐Heimer to display secondary climbing fiber degeneration in cerebellar cortex, it was found that too long post‐operative intervals could preclude its detection, since in both groups of animals it commenced earlier and disappeared sooner in the molecular layer.