bluuebunny/crossref_metadata_2025_split huggingface dataset:
Numerical estimates of neurons and glia in lateral geniculate body during retrograde degeneration
Authors: Chow Kao Liang , Dewson James H. 
Published: January 2005

AbstractStudies were made of decrease of neurons and proliferation of glial cells in the dorsal nuclei of lateral geniculate body of 32 rabbits and 12 cats who had undergone unilateral ablation of visual cortex up to 50 weeks prior to sacrifice. Results show that degeneration occurred in 80% of neurons in rabbit lateral geniculate body within three days, and 95% disappeared within four weeks. In comparison, degeneration was present in only 70% of neurons in the cat nucleus at the seventh post‐operative day, and about 26% remained normal up to the fiftieth week. Glial cell reactions were differential and complex: astrocytes showed rapid proliferation with gradual return to normal, while oligodendrocytes and microglia increased more slowly, maintaining a high level over 50 weeks.
Failure to produce postural tremor by mesencephalic lesions in cats
Authors: Ganes T. , Kaada B. R. , Nyberg‐Hansen R. 
Published: January 2005

AbstractAttempts were made to produce postural tremor (i.e., tremor at rest) in 24 cats by electrolytic lesions of the ventromedial tegmental area of the mesencephalon. In a number of previous studies in primates destruction of apparently the same region has resulted in postural tremor. The primary target was interruption of nigrofugal fibers or destruction of the pars compacta of the substantia nigra. Such lesions were combined with lesions of the nucleus ruber or the rubrospinal fibers, the reticular substance, the brachium conjunctivum, the medial part of the pes pedunculi, and others. No tremor was produced in cats by such lesions. The different results in primates and cats are possibly explained as due to a species difference.
Nuclear configuration of the diencephalon of Tamandua tetradactyla and Myrmecophaga jubata
Authors: Kaelber William W. 
Published: January 2005

AbstractThe nuclear configuration of the diencephalon of Tamandua tetradactyla (lesser anteater) is figured, described and compared with that of Myrmecophaga jubata (greater anteater) and other mammals, particularly the cat. Their nuclear organization represents, in general, all the elements (or their homologues) found in the mammalian diencephalon.There is an unusually large nucleus centralis lateralis which penetrates into the nucleus medialis dorsalis from above. The size of the latter group, in the presence of a poorly developed orbitofrontal cortex, suggests that it is primarily dependent upon the marked development of the corpus striatum. The nuclei of the tractus habenulopeduncularis are displaced ventrally, apparently by the medial enlargement of the nucleus centralis lateralis. The nuclei parataeniales bear strong resemblance to those in the armadillo.There is no nucleus ventralis pars anterior in either Tamandua or Myrmecophaga. The nucleus ventralis medialis is much larger than that in carnivores. The presence of the nucleus submedius and its intimate relation to the nucleus anterior medialis of the anterior nuclear complex, accounts fairly well for questionable homologues in such forms as Tarsius.The existence of both the large‐celled nucleus of the optic tract and the nucleus limitans indicates the gradual incorporation, at least in part, of the former into the latter. Hypothalamic nuclei, except for the supraoptic and paraventricular groups, are rather poorly differentiated.
The red nucleus and its efferent nervous pathways in the monkey
Authors: Poirier L. J. , Bouvier G. 
Published: January 2005

AbstractA morphological study of the red nucleus and its efferent nervous pathways based on retrograde cellular degeneration (cell loss) and on degenerated fibers impregnated with osmic acid gave the folowing results. Interruption of the rubro‐tegmentospinal tract was associated with a complete disappearance of the cells in the contralateral magnocellular red nucleus and some cell loss in the adjoining tegmental gray. Interruption of the central tegmental bundle results in a complete cell loss in the parvicellular part of the ipsilateral red nucleus. Such a lesion is associated with degeneration of the rubro‐olivary fibers that terminate along the dorsal lamella of the ipsilateral principal olive. The interruption of the superior cerebellar peduncle does not lead to any cell loss in the red nuclei. The above findings suggest that in the monkey the red nucleus proper discharges exclusively downwards. The small‐celled part gives rise to fibers that travel in the ipsilateral central tegmental bundle and the large‐celled part gives rise to entirely crossed axons that descend in the rubro‐tegmentospinal tract. There apparently exist marked differences in the distribution of the nervous elements within the red nucleus and, correspondingly, in the origin of the efferent nervous pathways in the cat and in the monkey. The interruption of the rubro‐tegmentospinal tract does not lead per se to any noticeable motor impairment but appears to be an essential feature in the appearance of postural tremor and possibly in the production of other extrapyramidal signs in the monkey.
Cytoarchitectonic appearance of the isolated hypothalamus of the cat
Authors: Bleier Ruth , Bard Philip , Woods James W. 
Published: January 2005

AbstractNeuronal changes in the hypothalamus were studied in 24 cats following extensive forebrain ablations, usually accompanied by mesencephalic transaction. Postoperative survival periods ranged from 13 to 283 days.In the intact but isolated hypothalamus, severe degeneration was observed in the mamillary nuclei and nucleus of the diagonal band of Broca. Degenerative changes also occurred in portions of the lateral and posterior hypothalamic areas and the area of tuber cinereum. There was a suggestion of cell loss in the suprachiasmatic and infundibular nuclei. Cell loss and atrophy were seen also in subthalamic and entopeduncular nuclei and in globus pallidus. It was possible to correlate degenerative changes in some cells groups with removal of particular regions of the brain.When entire regions of the hypothalamus itself were also removed, little additional degeneration was seen until the ablation included all but a narrow rim of hypothalamic tissue dorsal and caudal to the optic chiasm.The lateral hypothalamic area is proposed as the main site of interconnections between medial hypothalamic cell groups and extrahypothalamic structures. The mamillary nuclei alone appear to be dependent upon extrahypothalamic connections. The possible significance of extensive connections between medial hypothalamic cell groups and the neurohypophysis is discussed as well as the possible role of hormones in the maintenance of hypothalamic neuron.
Dimensions of the dendritic spine in the sensorimotor cortex of the rat, cat, squirrel monkey and man
Authors: Jacobson Stanley 
Published: January 2005

AbstractMeasurements of dendritic spines have suggested that there is similarity in the dimensions of the spines in various mammals. The present study was undertaken to determine if there is any variation in the dimension of the dendritic spine in sensorimotor cortex of rat, cat, squirrel monkey and man.Unfixed slices of rat, cat, squirrel monkey and human sensorimotor cortex were stained with either the Golgi‐rapid or Golgi‐Cox technique. Ultrastructural observations were confined to albino rats that were perfuse‐fixed with buffered 2% osmium. With the electron microscope it was very difficult to find spines. In contradistinction, the Golgi method revealed hundreds of spines; consequently the random sample was made from the Golgi stained material.In all the examined mammals the mean length of the entire spine was about 2.0 μ (1.5–3.5) with its component parts, the stalk 1.0 μ long (0.5–2.0) and the bulb 1.0 μ in diameter (0.5–2.0). The bulb connects via the stalk with the dendrite. Synapses are only seen on the bulb; they were never found on the stalk. The size of the spine was similar in light and electron microscopy. Comparison of the size of the spines in cortex impregnated with Golgi‐rapid to those impregnated with the Golgi‐Cox technique shows that the size of the spine is the same regardless of the animal or Golgi method used.
Distribution of cholinesterase in the basal rhinencephalic structures of the coypu (Myocastor coypus)
Authors: Girgis M. 
Published: January 2005

AbstractThis paper describes the distribution of cholinesterase in the rhinencephalon of a macrosmatic rodent which had not been investigated previously. A detailed description is given of the arrangement of stained elements in the basal rhinencephalon and this is compared to the cytoarchitectonic arrangement revealed by the classical neurohistological methods. The basic pattern of staining in the coypu is similar to other macrosmatic mammals; points of difference are discussed. The effect of varying the incubation time and other factors are described and discussed fully. It is concluded that cholinesterase–containing fibers are in general better developed in older parts of the brain.
The distribution of 5′‐nucleotidase in the brain of the mouse
Authors: Scott Thomas Gilbert 
Published: January 2005

AbstractThe distribution of the enzyme 5′‐nucleotidase in the brain of the mouse is described in detail. The structures showing the greatest amount of activity are the corpus striatum, the substantia gelatinosa, the lateral longitudinal stria, the nodulus of the cerebellum and parts of the retina. In the cerebellum in particular, and to some extent in the hippocampus, the distribution is such as to suggest that the enzyme may be actively involved not only in simple biochemical processes but possibly also in some neurophysiological function.
Specific subtotal labyrinthectomy of the superior semicircular canals of the kangaroo rat
Authors: Clark David L. , Burns Roebrt D. 
Published: January 2005

AbstractUnlike most mammals the semicircular canals of the kangaroo rat (Dipodomys) are free of petrous bone in the cavity of the mastoid sinus. This particular anatomical feature enabled the extirpation of individual semicircular canals with little or no damage to other portions of the inner ear or nearby vessels and nerves.Removal of the two superior semicircular canals resulted in: (a) a deviation of the eyes in an anterioventral direction, (b) an extension of the hindlimbs posteriorly. (c) a bending of the head ventrally, and (d) a falling to the right or left side in an anterior direction. The duration of these symptoms lasted 20 to 22 minutes. A loss of balance and falling while grooming or standing on the hindlimbs was observed to last up to three weeks. There were apparently no chronic symptoms.
The organization of projections from the thalamic mediodorsal nucleus to the prefrontal cortex of the dog
Authors: Narkiewicz Olgierd , Brutkowski Stefan 
Published: January 2005

AbstractA study of the thalamofrontal connections of the dog was made by placing total or restricted lesions in the prefrontal cortex and examining the resulting retrograde degeneration in the mediodorsal nucleus of the thalamus as demonstrated by Nissl and Klüver‐Barrera techniques. While there is some overlap the general arrangement of the thalamofrontal projection has been established as follows: (1) the intermediate area of the thalamic mediodorsal nucleus, extending obliquely throughout the entire length of the nucleus, projects to the most rostral portion of the prefrontal cortex; (2) the posterolateral portion of the mediodorsal nucleus projects to the proreal gyrus and the caudal part of the orbital gyrus; (3) the antero‐medial portion of the nucleus sends projection fibers to the subproreal gyrus and a greater part of the orbital gyrus; (4) the anterodorsal portion of the nucleus projects to the medial surface of the prefrontal cortex.
Cytoarchitecture of the frontal lobe of the squirrel monkey
Authors: Rosabal Fabio 
Published: January 2005

AbstractSix Saimiri sciurea brains were studied. Coronal, horizontal, and sagittal sections were stained with cresyl violet. The frontal lobe map shows, anterior to the cental sulcus, a triangular area 4, agranularis giganto‐pyramidalis (FA). Anterior to area 4 is area 6, frontalis agranularis (FB), which differs from area 4 by the absence of Betz cells. Rostral to area 6 is area 8, frontalis intermedia (FC), a narrow, thick band of cortex, with a faint layer IV. Anterior to area 8 the cortex becomes thinner and more granular, its cells are smaller and this region is subdivided into area 9, frontalis granularis (FD), and area 10, fronto‐polaris (FE). Area 44 (FCBm) is on the inferior frontal gyrus, this cortex is granular limb of the arcuate sulcus is thin and granular, contains very large pyramidal cells in layers V and III: area 8a (FDT). The orbital cortex posteriorly shows an evident loss of layer IV; area 11 (FF). Area 50 is a narrow band of koniocortex in the inner wall of the fronto‐parietal operculum. On the gyrus rectus the cortex develops allocortical characteristics with a heavy layer V, area 12 (FG). The characteristics of limbic cortex (mesocortex) are present on the cingulate gyrus, area 24 (LA). Area 25 is found in the subcallosal region.
Excess vitamin A and development of the cerebral cortex
Authors: Langman Jan , Welch Gary W. 
Published: January 2005

AbstractIn previous experiments excess vitamin A, administered to pregnant rats during the early stages of gestation, was found to interfere with the mitotic activity of the neuro‐epithelial cells bordering the neural groove. The result was exencephaly and anencephaly in a high percentage of the newborn. The present work was undertaken to examine the influence of hypervitaminosis A on the behavior of the neuro‐epithelial cells of the cerebral hemisphere and the subsequent migration and differentiation of the neuroblasts during the later stages of development.Swiss‐Webster mice were treated with large doses of vitamin A on days 14 and 15 of gestation. When subsequently the cell cycle of the neuro‐epithelial cells lining the lateral ventricle of 15‐day fetuses was determined, vitamin A was found to increase both the duration of the mitosis and DNA synthetic period. In comparison with the controls, the total generation time was prolonged by approximately 40%. Since almost all neuroblasts of the cerebral cortex originate in the neuro‐epithelial zone bordering the lateral ventricle, the total number of neuroblast formed is in all probability less than normal. Indeed, prelimiinary data on the number of cells present in the cerebral cortex of 10‐day postnatal rats treated with excess vitamin A toward the end of pregnancy showed a decrease in cell density, indicating either a reduction in the number of cells formed or a degeneration of existing cells.In a second experiment Swiss‐Webster mice were treated with excess vitamin A during three successive days in the second half of pregnancy. The cerebral cortex of the newborn was examined one to ten days after birth. Histological examination revealed a rather sharply delineated zone of abnormal cells characterized by a lightly stained cytoplasm, a thick nuclear memberane, a desely stained nucleoplasm and several dark chromatin bodies. When the position of the zone containing the abnormal cells was analyzed and correlated with the day of formation in the neuroepithelial zone, it was found that the affected cells were neuroblasts already present in the cortex before the vitamin treatment was started. This indicates that excess vitamin A, given to pregnant mice during the later stages of gestation, influences the development of the cerebral cortex, not only by interfering with the production of cells in the neuroepithelial zone, but also by affecting the differentiation of existing neuroblasts. As a result of these anomalies, some of the newborn appeared to have abnormal patterns of behavior.
The striatum of the opossum, Didelphis virginiana. Description and experimental studies
Authors: Martin G. F. , Hamel Earl G. 
Published: January 2005

AbstractThe relationships and cytoarchitecture of the putamen, the caudate, the claustrum, the globus pallidus and the entopeduncular nuclei have been described for the opossum.The neocortical projections to these nuclei have ben studied by employing the Nauta‐Gygax technique ('54) and the Swank Davenport modification of the Marchi technique ('34) on animals in which neocortical lesions were previously placed. Degenerating fibers from every cortical lesion were observed to terminate in both the putamen and the caudate with the Nauta‐Gygax technique, whereas such connections were traced only to putamen woth the Marchi method. Terminations were present within the claustrum, but equivocal in the globus pallidus. In general, fibers from the more rostral cortices terminate in the rostral parts of both striatal nuclei, whereas fibers from more caudal neocortical areas project to more caudal parts of these same nuclei. In addition, the more dorsal or dorsomedial neocortical areas distribute more fibers to the caudate than to the putamen, whereas the opposite is true for the ventral or ventrolateral neocortical areas. Neocortical fibers did not project to the ventral, medial part of the head of the caudate which was cytoarchitectually different from the rest of the nucleus. A few fascicles of frontal, orbital and parietal origin terminated in the contralateral putamen and caudate after having decussated in the anterior commissure.
The lateral geniculate nucleus of the marsupial phalanger, Trichosurus vulpecula. An experimental study of cytoarchitecture in relation to the intranuclear optic nerve projection fields
Authors: Hayhow W. R. 
Published: January 2005

AbstractFrom a cytoarchitectural viewpoint four laminae are apparent in the normal dorsal lateral geniculate nucleus of the marsupial phalanger. The contra‐ and ipsilateral Nauta preterminal degeneration patterns produced by previous unilateral optic nerve section have been precisely delineated and related to these laminae. The terminations of the optic nerve fibers fractionate the nucleus into six laminae of which the crossed and uncrossed optic fibers each mainly supply three; crossed fibers terminate in laminae 2a, 3 and 6, uncrossed fibers terminate in laminae 1, 2b and 4+5. The “crossed” and “uncrossed” laminae alternate. Concealed lamination is a prominent and hitherto unsuspected characteristic of the organisation of the phalanger lateral geniculate nucleus. The most superficial lamina (1) is unusual in so far as it is mainly “uncrossed”. No other reported mammal except the primitive primate Tupaia shows this feature. Although the two intranuclear optic nerve projection fields are largely segregated, the segregation is only complete in laminae 3 and 4+5. Binocular overlap occurs in the remaining laminae, particularly in lamina 2b. The ventral lateral geniculate nucleus and the pretectal nuclear complex are confirmed as primary optic centers supplied by both crossed and uncrossed optic nerve fibers. Within the superior colliculus cells of the zonal, superficial gray and optic layers are in synaptic relationship with crossed fibers while the ipsilateral optic nerve fibers mainly terminate in a circumscribed region of the optic layer. There is no evidence that any component of the lateral thalamic nuclear complex is a terminal center for nerve fibers of retinal origin.
The development of the human amygdala during early embryonic life,
Authors: Humphrey Tryphena 
Published: January 2005

AbstractThe development of the human amygdaloid complex is described beginning at the time that it first appears, when the cerebral hemispheres begin to evaginate (approximately 8‐‐9 mm), and including a fetus of 27.4 mm CR length Both Nissl and protargol silver series, transversely and sagittally sectioned, were used.The earliest cell migration representing the striatal complex is from the germinal epithelium in the region of the interventricular foramen, lateral to the primordial hippocampal formation. This is the characteristic topographic location of the amygdala, which, therefore, is the first portion of the human striatal complex to appear embryologically. All of the amygdaloid nuclei identified develop by the migration of neuroblasts from the germinal epithelium.The three main subdivisions of the amygdaloid complex (anterior amygdaloid area, corticomedial complex and basolateral nuclear group) are identifiable almost immediately after the primordial amygdala appears (9.5 mm in the material studied). In this embryo the cortical and medial nuclei are identifiable, but the central nucleus was not seen until 22.2 mm and the nucleus of the lateral olfactory tract was not identified even in the oldest fetuses.The basolateral complex differentiates much later than the corticomedial complex and all of the nuclear components became identifiable at the same time (20.7 mm embryo). However the basal nucleus is best represented, the accessory basal next in size, and the lateral only just appearing. In the oldest fetus the subdivisions of the basal and accessory basal nuclei seen in the adult brain are recognizable. Even before the individual nuclei appear, the basolateral complex is much larger than the corticomedial complex. The lateral to medial rotation of the amygdaloid complex has not yet begun in the oldest fetuses, but the posterior end of the lateral ventricle is beginning to turn anteriorly.During early development, all cells of the amygdala are derived from the lateral striatal ridge, the only one present until 14.0 mm. At 20.7 mm and later neuroblasts are contributed from the medial striatal ridge also. Although the greater part of the basolateral amygdaloid complex is derived from the lateral ridge, some cells are contributed from the medial ridge, particularly to the accessory basal nucleus. By contrast, the corticomedial complex is derived in part from the medial striatal ridge, after it appears, even though the early development is from the lateral ridge.Comparisons between the amygdala at different developmental stages and the amygdala in fishes, in amphibians, in reptiles and in lower mammals are made. The amygdala in fishes, in amphibians, in reptiles and in lower mammals are made. The topographic relationships between the amygdala and the hippocampal formation, the piriform cortex and the caudate, the putamen and the globus pallidus are considered.
Chromatolysis in the hypoglossal nucleus of the rat: An electron microscopic analysis
Authors: Kirkpatrick Joel B. 
Published: January 2005

AbstractChromatolysis was induced by cutting the hypoglossal nerve in young rats and the hypoglossal nucleus was examined by light and electron microscopy. Mitochondria in chromatolytic and control neurons, compared quantitatively, showed no change through the sixth day. A decrease in the mitochondria to cytoplasm ratio was present at the tenth day. The glial cells of the nucleus showed a hyperplastic reaction during early stages. Loosening of contact between neurons and glia as well as complex invagination of neurons by glial processes was observed. Other findings included a prominent juxtanuclear Nissl mass in chromatolyic neurons and degenerating neurites in both ipsi‐ and contralateral nuclei.