bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mice doubly affected by “staggerer” and “weaver” conditions
Authors: Yoon Chai H. , Frouhar Zohreh R. 
Published: May 2005

AbstractIn order to study the mode of interaction in mice of mutant genes that affect the motor activities and cerebellar cytoarchitectonics, double mutants affected by both the “staggerer” and “weaver” conditions were produced. The cerebellum of the double mutant mouse showed features present in both of the two single mutant cerebella. As to the features that were common to both single mutant cerebella, they were either more accentuated or similar to those found in one of the two single mutants which showed the greater change, with the possible exception of cerebellar fissures.
Retinal structure in the smooth dogfish Mustelus canis: electron microscopy of serially sectioned bipolar cell synaptic terminals
Authors: Witkovsky Paul , Stell W. K. 
Published: May 2005

AbstractPortions of axons of bipolar cells in the retina of the smooth dogfish Mustelus canis were sectioned serially and examined by electron microscopy. The studied axons generally could be related to a bipolar cell sub‐type identified by light microscopy. Bipolar cell axons make ribbon synapses onto amacrine processes and ganglion cell dendrites, and onto ganglion cell perikarya. Bipolar cell ribbon synaptic complexes varied as to the number of post‐synaptic processes (1–3) and the orientation of the ribbon with respect to the post‐synaptic membrane. Amacrine processes made numerous conventional synapses onto bipolar cell axons, but reciprocal synapses between amacrine and bipolar cells constituted only 3–25% of all synapses observed.The number of ribbon synapses per unit area of bipolar cell axon membrane differed little among bipolar cell sub‐classes. However, the density of amacrine cell conventional synapses was markedly lower for thin, horizontally‐oriented bipolar cell axons than for axons of other bipolar cell types.Gap junctions were noted between bipolar cell axons of the same sub‐type. They are structurally similar to gap junctions between horizontal cells in Mustelus retina and to those found elsewhere in the nervous system.
The naso‐temporal division of the monkey's retina
Authors: Stone Jonathan , Leicester Jonathan , Sherman S. Murray 
Published: May 2005

AbstractBy sectioning one optic tract in each of four monkeys, and studying the distribution within each pair of retinas of the ganglion cells which remained after the affected ganglion cells had undergone retrograde degeneration, a description was obtained of the areas of a retina from which ganglion cells project to the ipsilateral and contralateral sides of the brain. Confirming previous work, ganglion cells in temporal retina were observed to project to the ipsilateral side, and cells in nasal retina to the contralateral side. It was noted, however, that ipsi‐ and contralaterally projecting areas of retina overlap along a vertically‐oriented median strip, which is about 1° wide, and is centred on the fovea. Within this strip ipsi‐ and contralaterally projecting cells intermingle. Some functional implications of this result are discussed.
Some observations on axonal degeneration resulting from superficial lesions of the cerebral cortex
Authors: Nauta H. J. W. , Butler Albert B. , Jane John A. 
Published: May 2005

AbstractThermal lesions were placed in the superficial cell layers of the neocortex in rats, cats, and tree shrews, and the resulting intracortical axonal degeneration was studied by the Fink‐Heimer technique and by electron microscopy. Certain features of the degeneration resulting from such lesions are common to each cortical area studied. Despite the finding of appreciable axonal degeneration spreading tangentially, the most conspicuous axonal degeneration in each area studied was noted to be oriented vertically with terminations occurring in the deeper layers, especially in the region of the large pyramidal cells of layer V. The bulk of the degeneration in the deeper layers was confined to an area coextensive with the boundaries of the superficial lesion.
A Golgi study of the rat dorsal lateral geniculate nucleus
Authors: Grossman A. , Lieberman A. R. , Webster K. E. 
Published: May 2005

AbstractGolgi‐Kopsch and Cox preparations of albino rat dorsal lateral geniculate nucleus show two classes of neuron. Class A cells (assumed geniculocortical relay cells) have tufted dendritic arborizations, smooth primary dendrites, occasional excrescence clusters at dendritic branch points, irregular, small excrescences along distal dendrites, and myelinated axons. A subclass, more common medially, has long, smooth, radiating dendrites that branch sparsely.Class B cells are small (c. 10 m̈ dia.) paucidendritic, and commonly bipolar. Their dendrites branch rarely and often run for long distances maintaining a uniform diameter. They are commonly orientated so that their dendrites extend either dorso‐ventrally or approximately antero‐posteriorly (i.e., parallel to either the representation of the vertical meridian or to the lines of projection). The dendrites bear complex appendages, often branched and several microns long, with en passant and terminal varicosities. Some class B cells also appear to have axons, but conclusive evidence is lacking. Class B cells may be intrinsic neurons, corresponding to the electrophysiologically identified inhibitory interneurons and to cells seen by electron microscopy to have presynaptic perikarya and dendrites. The complex dendritic appendages probably enter synaptic glomeruli within which they establish pre‐ and postsynaptic contacts. Whether class B cells are comparable with the Golgi type II cells of other thalamic nuclei remains an open question.Three classes of axons are also described, and their possible origins considered.
The distribution of catecholamines within the inferior olivary complex of the gerbil and rabbit
Authors: Hoffman Donald L. , Sladek John R. 
Published: May 2005

AbstractThe inferior olivary complex of pre‐adult and adult gerbils and rabbits was examined with the histochemical fluorescence technique for the intraneuronal‐demonstration of monoamines. The observed patterns were compared directly to those seen in the rat. Dissimilar distributions of monoamine‐containing varicosities were observed between these mammalian species. These data support the belief that monoamine distribution as previously reported for the rat brain is not a complete model for other mammals. Also, a question is raised concerning the existence of the previously reported monoamine‐containing cell bodies in this nuclear complex.
Projections of the nuclei of the periaqueductal gray matter in the cat
Authors: Hamilton Betty L. 
Published: May 2005

AbstractTo obtain more evidence in support of the theory of tri‐nuclear division of the periaqueductal gray matter (PAG) in the cat, the projection systems of each of the nuclei were investigated. Direct current lesions were stereotaxically placed in the three nuclei of the PAG and the resulting fibers of degeneration were stained by reduced silver impregnation techniques. Degenerating axons from the lesion in the nucleus medialis were traced ventrally to the tegmentum in a radiating pattern and rostrally to the fields of Forel and the ventral tegmental area. Descending fibers were traced to their termination in the dorsal tegemental nucleus. Lesions in the nucleus dorsalis resulted in no radiating or descending fibers of degeneration, but a bundle of degenerating fibers running within the PAG could be followed to the level of the mesencephalic‐diencephalic junction. Here the axons terminated in the pretectal area and the lateral habenular nucleus. The pattern of degeneration was completely ipsilateral for the two nuclear lesions described above and predominately ipsilateral for the third nucleus, the lateralis. From it, all the ascending fibers were ipsilateral, but the heavy radiating fibers to the tectum and tegmentum did extend somewhat to the contralateral side. The large bundle of axons of degeneration ran rostrally within the PAG to diencephalic levels and divided into numerous fasciculi and terminated in the periventricular gray, the posterior hypothalamus and numerous thalamic nuclei. The evidence that each nucleus projects differently supports the theory of tri‐nuclear division of the PAG.
The distribution of septal projections to the hippocampus of the rat
Authors: Mosko Sarah , Lynch Gary , Cotman Carl W. 
Published: May 2005

AbstractTerminal degeneration following lesions of the medial septal nucleus or of the contralateral hippocampus was mapped and compared with the distribution of acetylcholinesterase in the hippocampal formation of the rat. Previously unreported septal projections were found in the supragranular region of the dentate gyrus, an area which is also the locus of a dense band of acetylcholinesterase. This correspondence provides further support for the hypothesis that the enzyme is located in the septal efferents. These findings are combined with those of earlier workers in a hypothetical model of septo‐hippocampal relationships.
On the organization of cerebellar efferent pathways in the nurse shark (Ginglymostoma cirratum)
Authors: Ebbesson Sven O. E. , Campbell C. B. G. 
Published: May 2005

AbstractThe organization of the efferent fiber systems of the nurse shark cerebellum was studied with the Nauta and Fink‐Heimer techniques. Lesions of the cerebellar cortex produce a pattern of terminal degeneration restricted to select regions of the cortex, as well as ipsi‐ and contralateral cerebellar nuclei. We found no evidence of cortical axons projecting beyond the nuclei, to the medulla and spinal cord as has often been reported.Lesions involving the cerebellar nucleus reveal three efferent pathways. The ipsilateral descending cerebello‐bulbar (IDC) pathway extends as far caudal as the first spinal segment and issues fibers to the lateral parts of the reticular formation. The brachium conjunctivum splits into a larger ascending limb (BCA) and a smaller descending one (BCD). The latter descends to the caudal medulla terminating along its course in the medial reticular formation. The ascending limb provides an input to (1) a nucleus we have tentatively labelled the “red nucleus,” (2) the trochlear nucleus, (3) the oculomotor nuclei, (4) the midbrain central gray, and (5) a poorly differentiated nucleus in the dorsal thalamus.
Morphology of the inferior olivary complex of the rhesus monkey (Macaca mulatta)
Authors: Bowman James P. , Sladek John R. 
Published: May 2005

AbstractThe morphology of the inferior olivary complex was determined in the rhesus monkey (Macaca mulatta). The position, configuration, and relations of each of its components were ascertained in serial transverse sections extending from caudal through rostral poles of the complex. The medial accessory nucleus was divided into seven cell groups (labeled a through g). The principal nucleus consisted of well‐developed dorsal, ventral, and lateral lamellae and a criterion was established for distinguishing the boundaries of each. This distinction was based upon the pattern of invagination that developed in the principal nucleus in progressing rostrally from its caudal pole. The dorsal and lateral lamellae each presented a characteristic pattern of major invaginations, while the ventral lamella did not. Finally, a detailed comparison was made of the inferior olivary complex of the monkey with that of the cat as determined by other investigators. It was shown that the medial and dorsal accessory nuclei of the two species appeared similar and that the major difference between these species concerns the principal nucleus.
Fiber organization at the posterior spinal cord‐rootlet junction in man
Authors: Sindou M. , Quoex C. , Baleydier C. 
Published: May 2005

AbstractThe authors have carried out serial section analysis in an attempt to elucidate the fiber organization at the posterior spinal cord‐rootlet junction in Man. In the peripheral segment of the rootlet, large and small caliber fibers have no particular organization. On the contrary, at the level of the spinal cord‐rootlet junction, small caliber fibers are re‐grouped in the ventro‐lateral region, whilst the large fibers are central and dorso‐medial. After consideration of published experimental data, which show that the small caliber fibers activate the nociceptive system, the authors have carried out in Man selective sections of the small fibers for antalgic reasons. These selective posterior rootlet sections ‐ operation called selective posterior rhizidiotomy ‐ result in an analgesia without suppression of tactile epicritic and conscious proprioceptive sensitivities.
Blood supply to brains of ungulates with and without a rete mirabile caroticum
Authors: Gillilan Lois A. 
Published: May 2005

AbstractThe arterial blood supply to brains of some ungulates representing the orders Artiodactyla and Perissodactyla differs from that in most other mammals. Either the internal carotid or vertebral artery or both may fail to carry blood to the brains of these animals. In pig, ox and sheep the proximal segment of the internal carotid artery is absent. Instead, branches of the internal maxillary and/or the external carotid artery feed into an arterial rete mirabile caroticum. A distal segment of the internal carotid artery is reconstituted from the rete mirabile which divides into a rostral and a caudal division. In the ox the rete mirabile receives additional branches at its caudal end from the vertebral and occipital arteries. In these three animals the basilar artery is fed from its rostral end through the caudal divisions of the internal carotid arteries of either side.The horse has no rete mirabile. The internal carotid artery has a long course through its neck and forms an S‐shaped curve in the cavernous sinus before piercing the dura mater. It then divides into a rostral and a caudal division. The basilar artery in the horse is formed at its caudal end by the union of cerebral rami of the occipital arteries.The patterns of the superficial cerebral arteries in all the ungulates studied have distinct submammalian characteristics. These are evidenced by the multiple origins of the middle cerebral and posterior cerebral arteries and the presence of arterial circles in the basilar artery.The principal portion of the arterial rete mirabile always lies enmeshed in the venous plexus of the cavernous sinus. Additional venous plexuses are found intimately related to the extracranial rete mirabile in the pig and the basisphenoid portion of the arterial rete mirabile in the ox.
The optic tectum of a perciform teleost II. Fine structure
Authors: Laufer Miguel , Vanegas Horacio 
Published: May 2005

AbstractThe fine structure of the six layers in the optic tectum of the teleost Eugerres plumieri has been studied with the electron microscope. In the stratum marginale, parallel nonmyelinated axons synapse on spines of thick dendrites of pyramidal cells, resembling the organization of the cerebellar cortex molecular layer. In the stratum opticum, two populations of fibers are described which differ in diameter, position and origin. In the stratum fibrosum et griseum superficiale, characteristic terminals belonging to optic nerve afferents are large and irregular, contain pale mitochondria with sparse cristae and large empty spaces, abundant round vesicles, and, occasionally, dense core vesicles. Optic nerve terminals synapse on pyramidal cells, as well as on dendritic profiles of other cell types, without a glomerular organization. Most cell types observed in Golgi preparations have been identified. Particular emphasis is placed on the description of different types of terminals and their synaptic relations.
Rubrospinal projections in the rat
Authors: Brown Leroy T. 
Published: May 2005

AbstractFollowing stereotaxically placed lesions in the magnocellular and parvicellular portions of the red nucleus in a series of young adult albino rats, the site of termination of the rubrospinal fibers in the cervical cord has been studied using the Nauta‐Gygax and Fink‐Heimer silver methods and electron microscopy.Following three days survival the degenerating rubrospinal tract could be identified in the dorsal aspect of the lateral funiculus, principally contralateral to the lesion. Degenerating axons could be seen projecting to the base of the dorsal horn and intermediate regions of the ventral horn. Degenerating synaptic terminals were electron dense, contained remnants of synaptic vesicles and mitochondria, and usually made synaptic contact with small to medium size dendrites.This study finds that the rubrospinal tract in the rat projects chiefly to the base of the dorsal horn and intermediate regions of the ventral horn. The system forms axodendritic synapses with spinal neurons. This projection is in contrast to the dorsomedial projection of corticospinal terminals seen in this species. The significance of these apparently diverging pathways is discussed.
The retrograde intraaxonal transport of horseradish peroxidase in the chick visual system: A light and electron microscopic study
Authors: LaVail Jennifer H. , LaVail Matthew M. 
Published: May 2005

AbstractRetrograde transport of horseradish peroxidase (HRP) from the region of retinal genglion cell axon terminals back to the cell bodies has been studied by light and electron microscopy. After injection of HRP into the chick optic tectum, it was taken up by axon terminals and unmyelinated axons as well as by other processes and cell bodies of the outer tectal layers. Subsequently the HRP was obseved in vesicles, multivesicular bodies, cup‐shaped organelles and small tubules within axons in the stratum opticum, optic tract, optic nerve and optic fiber layer of the retina with accumulation in the retinal ganglion cell bodies. Pinocytosis of extracellular HRP along the axon shaft was rare. After a short postinjection interval, HRP was found in organelles within the axons of the optic nerve but not in the extracellular spaces. After larger injections or longer postinjection intervals, extracellular HRP diffused from the injection site to the back of the eye, but none was found in the extracellular spaces of the retina; ganglion cells were the only cells of the retina which contained HRP product. HRP disappeared from the cell bodies 3–4 days after transport. These findings suport the concept of intraaxonal retrograde movement of HRP.Within axons the vesicles carrying HRP frequently were partially or completely surrounded by a regualr array of microtubules. Doses of colchicine greater than 5–10 µ/eye administered 4 days before tectal injection of HRP interfered with the uptake and/or transport of HRP. HRP also moved in an anterograde direction in membrane‐bound vesicles within the ganglion cell axons, although apparently more slowly and in smaller quantities than in the retrograde direction.The localization of HRP in neurons of the isthmo‐optic nucleus following intravitreal injections has also been studied. The marker enzyme was found in neuronal cell bodies 4 hours after injection, indicating a rate of retrograde transport of at least 84 mm/day in these neurons.
Cytoarchitecture of cerebral cortex in snakes
Authors: Ulinski Philip S. 
Published: May 2005

AbstractCerebral cortex in snakes consists of three neuronal layers. Layer 1 contains primarily axons and dendrites ascending from lower layers, but does contain a few neurons. Layer 2 is characterized by the presence of many densely packed somas. Layer 3 usually contains many loosely packed somas. A layer of columnar ependymal cells lies beneath layer 3. Ependymal cells have processes which extend through layer 3 and into layer 2. Four cortical areas are defined by regional variations in the three neuronal layers. They form rostrocaudally aligned strips in the hemisphere and are named according to their position.

Medial cortex contains small, densely packed neurons in layer 2 whose dendrites ramify primarily in layer 1 in a candelabra pattern.
Dorsomedial cortex contains large, loosely packed neurons in layer 2 whose dendrites ramify in both layers 1 and 3 in a double pyramidal configuration.
Dorsal cortex contains a moderate number of circular and fusiform neurons in layers 2 and 3 which have double pyramidal or stellate dendritic fields.
Lateral cortex contains many loosely packed circular somas in layers 2 and 3 which have stellate or double pyramidal dendritic fields.
Caliber spectra of fibers in the fasciculus gracilis of the cat cervical spinal cord: A quantitative electron microscopic study
Authors: Hwang Yann‐Ching , Hinsman Edward J. , Roesel O. F. 
Published: May 2005

AbstractIn order to obtain a better understanding of the microscopic structure of the cat fasciculus gracilis, entire cross‐sections of the fasciculus were examined with the electron microscope. Twenty‐five thousand, two hundred and eighty‐four fibers were encountered in one fasciculus. The fiber caliber spectra obtained from the study show that the fasciculus gracilis at cervical level has a unique fiber distribution pattern. The fiber diameters range from less than 1 μ to 15 μ, however, 97% of fibers have diameters less than 8 μ; and the majority of the fibers are in the 2–5 μ range.
Single unit activity in the posteroventral cochlear nucleus of the cat
Authors: Godfrey Donald A. , Kiang Nelson Y. S. , Norris Barbara E. 
Published: May 2005

AbstractSingle unit activity in the posteroventral cochlear nucleus (PVCN) was recorded for a variety of stimulus conditions. The units were classified according to their response characteristics. The locations of units were plotted onto a three‐dimensional block model of the cochlear nucleus. Certain types of units that responded best to the onsets of stimuli were located predominantly in the octopus cell region of the PVCN. The remainder of the PVCN, which contains a rather heterogeneous collection of small and multipolar cells, was found to contain several types of units with the dominant type being “chopper” units.
Single unit activity in the dorsal cochlear nucleus of the cat
Authors: Godfrey Donald A. , Kiang Nelson Y. S. , Norris Barbara E. 
Published: May 2005

AbstractSingle unit activity was examined in three component layers of the dorsal cochlear nucleus (DCN): the molecular layer, the fusiform cell layer, and the polymorphic layer (deep DCN). Electrophysiological units were classified into types on the basis of their activity under a variety of stimulus conditions. In the molecular layer spike activity was small and difficult to isolate. Almost all units in the fusiform cell layer could be classified as either “pauser” or “buildup” units. Classification of units in the deep DCN was sometimes difficult, but “pauser,” “chopper,” and some “on” units were found. The “on” types of units tended to be located in the more superficial part of the deep DCN. Unit locations were referred to a three‐dimensional block model of the cochlear nucleus.