bluuebunny/crossref_metadata_2025_split huggingface dataset:
The morphology and distribution of striate cortex terminals in the inferior and lateral subdivision of the Macaca monkey pulvinar
Authors: Ogren Marilee P. , Hendrickson Anita E. 
Published: January 2005

AbstractThe origin of the various types of axon terminals in Macaca pulvinar remains uncertain because of the contradictory results obtained in EM degeneration studies. We have used EM‐autoradiography to determine the morphology of terminals in the inferior and lateral pulvinar which originate from neurons in visual cortex. After injections of H3 proline into area 17, both the small diameter (RS) and the large diameter (RL) terminals containing round vesicles and making asymmetric contacts are labeled in the two pulvinar subdivisions. Labeled and unlabeled terminals are intermixed within the pulvinar focus which suggests that the dendrites of the same pulvinar neuron receive overlapping inputs from several cortical areas. Because only 5% of the pulvinar terminals are RLs (Ogren and Hendrickson, '79), and this small number of RLs originates from at least two visual cortical areas plus the superior colliculus (Partlow et al., '77), superior colliculus input to inferior pulvinar is small compared to the combined RS and RL cortical input.Together the findings from this study and the preceding paper (Ogren and Hendrickson, '79), show that while pulvinar is typical of other thalamic nuclei in the structure of its neurons and synapses, it differs in that the input from subcortical structures is minimal. It is suggested that inferior and lateral pulvinar function principally as integrators of visual cortical information.
Synaptic contacts on glial cells in the abdominal ganglion of Aplysia californica
Authors: Colonnier M. , Tremblay J. P. , McLennan H. 
Published: January 2005

AbstractTwo types of glial cells have been identified in the neuropil and in the subcapsular space of the abdominal ganglion of Aplysia californica. In the neuropil, a first type of glial cell has a light staining cytoplasm and gives rise to processes which may contain bundles of filaments, a flocculent material or bundles of microtubules and membranous sacs. Synaptic contacts have been seen very rarely on their somata and more frequently on their “filamentous” and “flocculent” processes. A second type of glial cell has a darkly staining cytoplasm and gives rise to dense processes. Synaptic contacts are frequently seen on these processes. In the subcapsular zone, there are also two types of glial cells, one with a clear and the other with a dense cytoplasm. The processes of the clear glial cells contain glycogen‐like particles and sometimes bundles of filaments. These processes surround the bundles of neuronal profiles which form the perisomatic plexus. Such enveloping processes receive synaptic contacts from the neuronal profiles in the bundles. The dense glial cells of the subcapsular zone also receive synaptic contacts, but this is a rare occurrence.
The rabbit and the cat: A comparison of some features of response properties of single cells in the primary visual cortex
Authors: Murphy E. Hazel , Berman Nancy 
Published: January 2005

AbstractReceptive field characteristics of single cells in primary visual cortex of rabbit were studied. Seventy‐two percent of cells were found to be orientation selective, and the remainder had concentric, uniform, movement selective or pure direction selective receptive fields. Single cells were also recorded from primary visual cortex of cat to permit a comparison of visual cortical organization in cats and rabbits. Laminar organization of receptive field types was observed in rabbits which was similar in most respects to that described in the cat. Although the major categories of orientation selective cells (simple, complex, hypercomplex) were similar for both cat and rabbit, many differences emerged: (I) tuning of orientation selectivity was narrower in cats than in rabbits; (II) units which preferred oblique orientations were less frequently represented in rabbits than in cats; (III) orientation preferences appeared to be arranged in cluster in rabbit cortex; in rabbits we found no evidence of the columnar organization of orientation selectivity which characterizes cat visual cortex.A comparison of our data with those previously reported for mouse, rat, hamster and opossum visual cortex suggest that mammals in which a significant proportion of visual cortical cells are not orientation selective have in common certain patterns of cortical organization involving a less precise and less specialized representation of stimulus orientation.
Projections of lamprey spinal neurons determined by the retrograde axonal transport of horseradish peroxidase
Authors: Tang D. , Selzer M. E. 
Published: January 2005

AbstractThe spinal cords of larval sea lampreys (Petromyzon marinus) and adult river lampreys (Ichthyomyzon unicuspis) were injected with horseradish peroxidase through a transection 1 cm caudal to the last gill. Some animals also had a spinal hemisection 1 cm caudal to the injection. After recovery periods of 1 to 52 days, the spinal cords were treated with diaminobenzidine and hydrogen peroxide, and the projections of various cell types determined in wholemount slides. From these observations the following conclusions were drawn.Most dorsal cells (primary sensory cells) are bipolar with a long rostral projection and a short caudal projection of no more than 5‐10 mm. Both processes travel in the ipsilateral dorsal column. Their peripheral processes enter the dorsal roots as branches of their central axons. Some dorsal cells send processes out three or more dorsal roots both rostral and caudal to the cell body.Myotomal motoneurons have characteristic locations in the medial gray column and send prominent transversely oriented dendrites into the lateral columns. A few motoneurons are unusually large.In addition to giant interneurons the majority of smaller rostrally projecting interneurons also have decussating axons. A recently described cell type, the oblique bipolar cell, appears to have an exclusively crossed rostral projection.Although most edge cells project rostrally, as many as 20% may have a caudal projection or both rostral and caudal projections. Edge cells project equally to the ipsilateral and contralateral spinal hemicord, but their processes do not extend more than about 18 mm in sea lamprey larvae and 37 mm in adult river lampreys.Lateral cells project exclusively to the ipsilateral caudal hemicord. A few cells which resemble lateral cells in location and in possessing large lateral dendrites, project rostrally. However, these have atypical morphologic features which probably distinguish them from true lateral cells.Thus far, regardless of cell type, all decussating axons seem to pass ventral to the central canal, while decussating medial dendrites pass dorsally.
Relations between cell body size, axon diameter and axon conduction velocity of triceps surae alpha motoneurons during the postnatal development in the cat
Authors: Cullheim S. , Ulfhake B. 
Published: January 2005

AbstractTriceps surae α‐motoneurons in cats of different postnatal ages were stained intracellularly with horseradish peroxidase (HRP) and studied light microscopically. In individual neurons, the mean diameter of the cell body and the intramedullary axon diameter were measured and related to the axon conduction velocity.The mean diameter of the cell body grew from 39.6 μm at birth to 57.6 μm in the adult cat, while the corresponding figures for the intramedullary axon diameters were 2.4 μm and 6.7 μm. During the same period of time, the axon conduction velocity increased from 11.3 m/s to 93.5 m/s, and the ratio between the conduction velocity and the intramedullary diameter of the axon (CV/d ratio) increased from 4.6 to 14.1.The results indicate that the growth of the cell body is smaller and completed earlier than the growth in diameter of the intramedullary and, in particular, the peripheral parts of the axon. The considerable change of the CV/d ratio during the postnatal development may be explained by previously described immature morphological properties of the axon in very young kittens, and by a changing relation between the dimensions of the intramedullary and peripheral parts of the axon.
In vivo metabolic activity of a putative circadian oscillator, the rat suprachiasmatic nucleus
Authors: Schwartz W. J. , Davidsen L. C. , Smith C. B. 
Published: January 2005

AbstractThe suprachiasmatic nucleus (SCN) has been proposed as a site for an endogenous circadian oscillator in mammals, since lesions of the nucleus abolish a wide spectrum of overt circadian rhythms. To demonstrate that a directly measurable property of the SCN itself in intact (unlesioned) animals is affected by environmental light and exhibits circadian rhythmicity, we used the autoradiographic 2‐deoxy‐D‐[14C]glucose method to determine glucose utilization of rat SCN under a variety of lighting conditions. Our experiments indicate an important role for the SCN in circadian rhythm organization, and we believe the deoxyglucose method will prove useful as a tool for better understanding the functions and mechanisms of circadian clocks.
Quantitative analysis of sex differences in hormone accumulation in the zebra finch brain: Methodological and theoretical issues
Authors: Arnold Arthur P. 
Published: January 2005

AbstractThe autoradiographic method was used to compare the numbers of hormone accumulating cells in several brain regions in male and female zebra finches (Poephila guttata) after injection of tritiated testosterone. The brain regions examined were the caudal nucleus of the hyperstriatum ventrale (HVc), magnocellular nucleus of the anterior neostriatum (MAN), robust nucleus of the archistriatum (RA), nucleus intercollicularis of the midbrain (ICo), the tracheosyringeal hypoglossal motor nucleus (nXIIts), and periventricular magnocellular nucleus of the anterior hypothalamus (PVM). All but the last of these regions are thought to be involved in the control of vocalizations in passerine song birds. Males have significantly more labelled cells in HVc and MAN. In RA, there is no difference in total percentage of labelled cells, but there is a sex difference in size distribution of labelled cells. No sex difference was detected in other brain regions. These differences are found when using a criterion for cell labelling which is based on the Poisson distribution, and the relative merits are evaluated of various quantitative criteria used in the analysis of steroid autoradiograms. The magnitude of the observed sex difference may be influenced by several biasing factors, yet the sex difference persists when corrections are applied to eliminate the biases, indicating that the sex difference is not an artifact of autoradiographic procedure. The magnitude of the sex difference in hormone accumulation has certain implications for the process of sexual differentiation of the brain.
Secondary trigeminocerebellar projections in sheep studied with the horseradish peroxidase tracing method
Authors: Saigal R. P. , Karamanlidis A. N. , Voogd J. , Mangana O. , Michaloudi H. 
Published: January 2005

AbstractSecondary trigeminocerebellar connections have been studied with HRP histochemistry in 25 sheep. The results indicate that almost all of the cerebellar cortex except flocculus, ventral paraflocculus and lobules I‐IV receives bilateral (mostly ipsilateral) fibers from the trigeminal nuclei.A topographical organization of trigeminocerebellar fibers is present. The mesencephalic tract nucleus projects to the anterior lobe, the simple lobule (HVI), lobules VI, VIII, and the dorsal paraflocculus. The ventral group of the princeps and spinal tract (mainly IDV) nuclei projects to all lobules studied in vermis and hemispheres. More dorsal parts of these nuclei have a more restricted projection field including the vermal lobules VI, VII, and IX and the hemisphere. Cells within and ventral to the motor nucleus of the trigeminal nerve were found labeled after injections into the anterior lobe, the simple lobule, and lobule IX. Labeled cells in the region of the nucleus ovalis and close to the solitary tract project to the simple and paramedian lobule and lobule IX.
Acetylcholinesterase mutants in drosophila and their effects on the structure and function of the cental nervous system
Authors: Greenspan Ralph J. , Finn James A. , Hall Jeffrey C. 
Published: January 2005

AbstractMutations that eliminate acetylcholinesterase (AChE) activity were used to study the effects of disrupted acetylcholine metabolism on the form and function of the central nervous system in Drosophila melanogaster. Mutants in the Ace gene, which have no AChE activity, usually die in early development, but the postembryonic effects of this lesion can be studied in genetic mosaics, or with conditional mutants.Adult mosaics, which expressed Ace mutations in part of their CNS, exhibited morphological defects in any ganglionic neuropile whose cells were mutant. The defects included reduction in ganglionic volume, a condensed appearance, and for a very large clone, degeneration. Examination of many such mosaics indicated that small clones restricted to one side of the CNS were not usually lethal. However, mosaics with large clones, with clones on either side of the posterior slope of the protocerebrum, or with clones encompassing symmetrical structures on both sides of the CNS rarely survived to adulthood. Mosaics with AChE‐null tissue on either side of the optic lobes or the posterior‐inferior protocerebrum had marked deficits in optomotor behavior, although they were outwardly normal in their movements and posture. Mosaics with Ace mutant tissue in the first‐order optic lobe, the lamina, lacked a synaptic component of the electroretinogram, the “off” transient. Tests of courtship behavior revealed that AChE mosaics with mutant clones in the superior protocerebrum were often capable of demonstrating male courtship. However, their behavior was quantitatively and perhaps qualitatively deficient.In order to study critical periods for the effects of mutant AChE, temperature‐sensitive mutations of the Ace gene were isolated. Flies bearing certain of these new mutations produced AchE activity that was thermolabile in vivo and in vitro. The critical period during which the mutants were most susceptible to conditional lethality was late in embryogenesis.
Prefrontal system in the rat visualized by means of labeled deoxyglucose—further evidence for functional heterogeneity of the neostriatum
Authors: Divac Ivan , Diemer Nils H. 
Published: January 2005

AbstractAn epileptic focus was formed in the anteromedial part of the prefrontal cortex in rats by means of intracortical injection of penicillin, and radioactively labeled deoxyglucose was immediately injected intravenously. Autoradiograms revealed that, in addition to the injected cortical area, a number of formations increased their consumption of deoxyglucose.The labeled formations were the posterior medial and perirhinal cortical areas, the anteromedial part of the neostriatum, the anterior and intermediodorsal part of globus pallidus, the entopeduncular nucleus, the reticular portion of the substantia nigra, the claustrum, and the basolateral nucleus of amygdala. In addition, several thalamic nuclei were activated, including the entire parataenial, paraventricular, anteromedial, and axial nuclei, as well as distinct parts of the mediodorsal and lateral nuclei and, in the instances of spread of cortical activity to the dorsal surface, of the ventral nucleus. In some animals, activation of the ventral tegmental area of Tsai was also found.All these formations have previously been shown by neuroanatomcial techniques to be directly connected with the anteromedial cortex of the neostriatum. Some of them were included in the “prefrontal system.” The present findings, in agreement with earlier neurobehavioral studies, indicate that, in the rat, the anteromedial part of the neostriatum, but not other neostriatal regions, is functionally related to the anteromedial part of the prefrontal cortex.The present and earlier similar studies suggest that the mammalian forebrain contains a number of “systems”, each of which consists of a neocortical area and a set of associated subcortical sites.
Relationship between enkephalinergic neurons and the vasopressin‐oxytocin neuroendocrine system of the cat: An immunohistochemical study
Authors: Micevych Paul , Elde Robert 
Published: January 2005

AbstractLocalization of enkephalins and opiate binding sites in the central nervous system of rats has been reported by several authors. These studies did not reveal an extensive enkephalinergic system in the hypothalamo‐hypophyseal axis of rats. The present paper reports on an extensive enkephalinergic system in the cat hypothalamo‐hypophyseal system. Sections of paraformaldehyde fixed cat hypothalami were incubated with anti‐methionine enkephalin serum, anti‐vasopressin serum, and anti‐oxytocin serum. Immunohistochemical localization of methionine enkephalin fibers and terminals in the median eminence, hypophyseal stalk, and pars nervosa was similar, but not identical to the distribution of vasopressin and oxytocin in these structures. Neuronal perikarya localized with the three antisera in the nucleus supraopticus and nucleus paraventricularis were of a similar size and morphology. In cats treated with colchicine prior to sacrifice, the anti‐methionine enkephalin serum revealed a group of periventricular cell bodies. Cell bodies were not localized in this area with anti‐vasopressin or anti‐oxytocin sera. The functional significance of such an extensive enkephalinergic system in the cat hypothalamo‐hypophyseal axis is discussed.
A light and electron microscopic study of the effects of 3‐acetylpyridine intoxication on the inferior olivary complex and cerebellar cortex
Authors: Anderson W. A. , Flumerfelt B. A. 
Published: January 2005

AbstractThe effects of 3‐acetylpyridine (3‐AP) intoxication on the inferior olivary complex and cerebellar cortex of the rat were examined at both the light and electron microscopic level. Following intraperitoneal injection of 65 mg of 3‐AP per kg body weight, the inferior olivary neurons were observed to undergo a rapid form of electron dense degeneration. A complete bilateral involvement of the nuclear complex was well advanced as early as 12 hours following injection. Marked astrocytic proliferation also occurred by 12 hours and appeared essential for neuronal fragmentation and disintegration. Microglial activity was prominent in the later stages, from 60 hours onwards, and participated in the phagocytic removal of degenerating neuronal fragments. By the end of the second week, all cytoplasmic and nuclear debri was removed. Concurrently, degenerative changes in the cerebellar cortex were evident from 12 hours onwards. All climbing fiber varicosities were observed to be degenerative as early as 24 hours following treatment. Electron microscopic observations revealed that these electron dense fragments were largely phagocytized and cleared by Bergmann glial cells around 7 days. The sensitivity of the olivocerebellar system to 3‐AP thus provides a convenient and selective means of eliminating all of the inferior olivary neurons and their axons, the climbing fibers of the cerebellar cortex. In contrast to the more conventionally used electrolytic methods, 3‐AP causes a complete bilateral ablation of all olivary neurons while avoiding the problems inherent to electrolytic procedures, such as incomplete destruction of the nucleus and involvement of fibers of passage.
Prenatal and postnatal development of GABA‐accumulating cells in the occipital neocortex of rat
Authors: Chronwall Bibie , Wolff Joachim R. 
Published: January 2005

AbstractThe development of the 3H‐GABA‐accumulating cells in the neocortex has been followed by light microscopical autoradiography, and after resectioning of the original autoradiograms, by electron microscopy. The validity of the methods used are discussed. The study has been limited to the primary visual cortex and its precursors of rat, from embryonic day (E) 15 to adult.GABA‐accumulating cells were found from E 16 onwards in the occipital cortex, which is one to two days after cells arrive in the pallial anlage and one day before the first synapses have been found. Until E 18, the prevalent positions of labeled cells were in lamina I and below the cortical plate. Later, labeled cells also occurred as strands within the cortical plate. During the perinatal period, more and more GABA‐accumulating neurons and glial cells began to differentiate and show a characteristic distribution at the periphery of unlabeled cell clusters. From postnatal day 11, no apparent change in density or position of labeled neurons took place.At prenatal stages, two main types of labeled cells were found: 1) Comparatively large cells with rounded nuclei and rough endoplasmic reticulum consisting of narrow, electron‐lucent cisterns. These cells were tentatively identified as preneurons. 2) Smaller, polymorphous cells with irregular nuclei and rough endoplasmic reticulum with wide cisterns filled with a dense matrix. These cells are probably precursors of glial cells. Both labeled neurons and glial cells were identified at postnatal stages. In young and adult rats, only neurons to be characterized as nonpyramidal neurons were labeled. Synapses were not found on the perikarya of labeled cells until E 21. Also, in postnatal preparations, labeled neurons showed few axo‐somatic synapses.These data were correlated with other events of the structural and functional development of the neocortex. The delay between the appearance of GABA accumulating cells and synaptogenesis indicates that apart from being an inhibitory neurotransmitter, GABA might play a specific morphogenetic role in synaptogenesis. This could even be its primary function during early developmental stages.
Corticopontine visual projections in macaque monkeys
Authors: Glickstein Mitchell , Cohen Janet Lee , Dixon Bryan , Gibson Alan , Hollins Mark , Labossiere Eilene , Robinson Farrel 
Published: January 2005

AbstractThese experiments were designed to study the projections to the pons from visual and visual association cortex of monkeys by degeneration staining and horseradisch peroxidase (HRP) methods. When lesions were made in these cortical visual areas, degenerated fibers were found in the rostral dorsolateral area of the pontine nuclei. When HRP was injected among visually responsive cells in this region of the pons, layer V cortical pyramidal cells were labeled. These labeled cells were concentrated most heavily on both banks of the superior temporal and intraparietal fissures, and on the rostral bank of the parieto‐occipital fissure. The efferent targets and receptive field properties of these cortical regions are consistent with their possible role in visual guidance of movement.