The Experts below are selected from a list of 1989 Experts worldwide ranked by ideXlab platform
Alán Alpár - One of the best experts on this subject based on the ideXlab platform.
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perisynaptic aggrecan based extracellular matrix coats in the human lateral Geniculate Body devoid of perineuronal nets
Journal of Neuroscience Research, 2012Co-Authors: Dávid Lendvai, Gert Bruckner, Markus Morawski, László Négyessy, Gabor Baksa, Tibor Glasz, Lajos Patonay, R.t. Matthews, Th. Arendt, Alán AlpárAbstract:The extracellular matrix surrounds different neuronal compartments in the mature nervous system. In a variety of vertebrates, most brain regions are loaded with a distinct type of extracellular matrix around the somatodendritic part of neurons, termed perineuronal nets. The present study reports that chondrotin sulfate proteoglycan-based matrix is structured differently in the human lateral Geniculate Body. Using various chondrotin sulfate proteoglycan-based extracellular matrix antibodies, we show that perisomatic matrix labeling is rather weak or absent, whereas dendrites are contacted by axonal coats appearing as small, oval structures. Confocal laser scanning microscopy and electron microscopy demonstrated that these typical structures are associated with synaptic loci on dendrites. Using multiple labelings, we show that different chondrotin sulfate proteoglycan components of the extracellular matrix do not associate exclusively with neuronal structures but possibly associate with glial structures as well. Finally, we confirm and extend previous findings in primates that intensity differences of various extracellular matrix markers between magno- and parvocellular layers reflect functional segregation between these layers in the human lateral Geniculate Body. © 2011 Wiley Periodicals, Inc.
E Ogbonna - One of the best experts on this subject based on the ideXlab platform.
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histochemical assessment of moringa oleifera oil and walnut oil on cadmium induced lateral Geniculate Body damage in developing male wistar rats rattus novergiccus
Anatomy journal of Africa, 2019Co-Authors: O D Omotoso, S A Adelakun, E Ogbonna, B P Akwu, I J IdomehAbstract:The brain is vulnerable to oxidative damage due to its high oxygen consumption. This Study investigate the effects of cadmium on the lateral Geniculate Body of developing male wistar rats and ameliorative potential of Moringa oleifera seed oil and walnut oil extracts. Seven groups of five animals each were used in this experiment. Group A received 3ml of 0.9% normal saline; group B received 2.5mg/kg bw of 3CdSO 4 .8H 2 O, group C received 5mg/kg bw vitamin C & 6mg/kg bw vitamin E, group D received 5mg/kg bw vitamin C & 6mg/kg bw vitamin E + 2.5mg/kg bw Cd, group E received 2.5mg/kg bw Cd + 4mg/kg bw Moringa oleifera oil, group F received 2.5mg/kg bw Cd + 4mg/kg bw walnut oil, while group G received 2.5mg/kg bw Cd + 2mg/kg bw walnut + 2mg/kg bw Moringa oleifera oil concomitantly for 3weeks. Parameter tested includes LDH, G6PD in brain tissues, SOD and GPx enzymes in brain homogenates and serum and cresyl fast violet stain in the brain tissues. Cd administration significantly increased SOD, GPx, LDH and decreased G6PD level in brain tissue and decreased their activity in serum when compared with Group A control rats. There was marked reduction and lost in the distribution of nissl substances of the studied tissues of Cd administered animals. However, administration of vitamin C & E, walnut and Moringa oleifera oil restored damaged tissues. Walnut and Moringa oleifera seed oil therefore attenuated the oxidative damage and morphological changes induced by cadmium in the lateral Geniculate Body of the brain of the young male wistar rats. Key Words : Lateral Geniculate Body, Antioxidant, Histochemical, Cadmium, Oxidative Damage
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histomorphological characterization of moringa oleifera oil and walnut oil on cadmium induced lateral Geniculate Body damage in adult wistar rats rattus novergiccus
Journal of Biology and Medicine, 2019Co-Authors: O D Omotoso, S A Adelakun, I J Idomeh, E OgbonnaAbstract:Background: Cadmium (Cd) has been reported to cause distinct neurotoxic effects in adult and newborn animals. This study was designed to investigate some of the effects caused by cadmium on the lateral Geniculate Body of adult male wistar rats and the ameliorative properties of antioxidants present in Moringa oleifera seed oil and walnut oil extracts.
Jeffery A Winer - One of the best experts on this subject based on the ideXlab platform.
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gabaergic organization of the cat medial Geniculate Body
The Journal of Comparative Neurology, 1999Co-Authors: Camillan L Huang, David T Larue, Jeffery A WinerAbstract:A study of neurons and processes (puncta) immunolabeled by antibodies to ! -aminobutyric acid (GABA) or glutamic acid decarboxylase was undertaken in the medial Geniculate Body of the adult cat. The proportion and types of GABAergic cells were determined with high resolution methods, including postembbedding immunocytochemistry on semithin plastic sections. A second goal was to draw parallels and differences between the auditory thalamus and other thalamic nuclei. Finally, the types of GABAergic puncta and their concentration in the three major subdivisions of the medial Geniculate Body were analyzed. The results were that (1) each division had many GABAergic neurons, averaging approximately 26% of the neuronal population; (2) the ventral division had the highest proportion of these cells (33%), the medial division the fewest (18%), and the dorsal division was intermediate (26%); (3) there was a gradient in the proportion of GABAergic neurons, i.e., the ventral and medial division values increased caudorostrally, whereas the value in the dorsal division declined; (4) the predominant GABAergic cell type in each division was a small neuron with a soma approximately 10‐12 µm in diameter; (5) a small population of much larger GABAergic neurons was present mainly in the dorsal division; (6) in addition to the fine, granular puncta in each division, a type of giant GABAergic puncta was found only in the dorsal division nuclei. The results obtained with the two antibodies were essentially identical. These findings suggest a structural basis for qualitative differences in the distribution of GABAergic processing within the medial Geniculate complex. The GABAergic arrangement in the ventral division was stereotyped, with only one type of putative GABAergic interneuron, and the puncta were correspondingly homogeneous. In contrast, the dorsal division had two types of GABAergic neurons, and the giant GABAergic puncta represent a new substrate for inhibitory interactions. The medial division also had more than one type of GABAergic neuron and a slightly lower concentration of puncta. These qualitative and quantitative distinctions suggest a morphologic basis for possible differences in inhibitory processing among medial
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neural architecture of the rat medial Geniculate Body
Hearing Research, 1999Co-Authors: Jeffery A Winer, Jack B Kelly, David T LarueAbstract:The rat medial Geniculate Body was subdivided using Nissl preparations to establish nuclear boundaries, with Golgi-Cox impregnations to identify projection and local circuit neurons, and in fiber stained material to delineate the fiber tracts and their distribution. Three divisions were recognized (ventral, dorsal and medial): the first two had subdivisions. The ventral division had lateral and medial parts. The main cell type had bushy tufted dendrites which, with the afferent axons, formed fibrodendritic laminae oriented from dorso-lateral to ventro-medial; such laminae were not as regular medially, in the ovoid nucleus. The dorsal division contained several nuclei (dorsal superficial, dorsal, deep dorsal, supraGeniculate, and ventrolateral) and neurons with radiating or bushy dendrites; the nuclear subdivisions differed in the concentration of one cell type or another, and in packing density. A laminar organization was present only in the dorsal superficial nucleus. Medial division neurons were heterogeneous in size and shape, ranging from tiny cells to magnocellular neurons; the various cell types intermingled. so that no further subdivision could be made. This parcellation scheme was consistent with, and supported by, the findings from plastic embedded or fiber stained material. There were very few small neurons with locally ramifying axons and which could perform an intrinsic role like that of Golgi type II cells. Their rarity was consistent with the small number of such profiles in plastic embedded or Nissl material and the few GABAergic medial Geniculate Body neurons seen in prior immunocytochemical work. While similar neuronal types and nuclear subdivisions are recognized in the rat and cat, there may be major interspecific differences with regard to interneuronal organization in the auditory thalamus whose functional correlates are unknown.
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gabaergic feedforward projections from the inferior colliculus to the medial Geniculate Body
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jeffery A Winer, David T Larue, R Saint L Marie, Douglas L. OliverAbstract:Abstract A novel and robust projection from gamma-aminobutyric acid-containing (GABAergic) inferior colliculus neurons to the media] Geniculate Body (MGB) was discovered in the cat using axoplasmic transport methods combined with immunocytochemistry. This input travels with the classical inferior colliculus projection to the MGB, and it is a direct ascending GABAergic pathway to the sensory thalamus that may be inhibitory. This bilateral projection constitutes 10-30% of the neurons in the auditory tectothalamic system. Studies by others have shown that comparable input to the corresponding thalamic visual or somesthetic nuclei is absent. This suggests that monosynaptic inhibition or disinhibition is a prominent feature in the MGB and that differences in neural circuitry distinguish it from its thalamic visual and somesthetic counterparts.
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evolution of gabaergic circuitry in the mammalian medial Geniculate Body
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jeffery A Winer, David T LarueAbstract:Abstract Many features in the mammalian sensory thalamus, such as the types of neurons, their connections, or their neurotransmitters, are conserved in evolution. We found a wide range in the proportion of gamma-aminobutyric acidergic (GABAergic) neurons in the medial Geniculate Body, from <1% (bat and rat) to 25% or more (cat and monkey). In the bat, some medial Geniculate Body subdivisions have no GABAergic cells. Species-specific variation also occurs in the somesthetic ventrobasal complex. In contrast, the lateral Geniculate Body of the visual system has about the same proportion of GABAergic cells in many species. In the central auditory pathway, only the medial Geniculate Body shows this arrangement; the relative number of GABAergic cells in the inferior colliculus and auditory cortex is similar in each species. The range in the proportion of GABAergic neurons suggests that there are comparative differences in the neural circuitry for thalamic inhibition. We conclude that the number of GABAergic neurons in thalamic sensory nuclei may have evolved independently or divergently in phylogeny. Perhaps these adaptations reflect neurobehavioral requirements for more complex, less stereotyped processing, as in speech-like communication.
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cytoarchitecture of the medial Geniculate Body in the mustached bat pteronotus parnellii
The Journal of Comparative Neurology, 1994Co-Authors: Jeffery A Winer, Jefferey J WenstrupAbstract:The cytoarchitectonic organization of the medial Geniculate Body and adjoining thalamic nuclei was analyzed in the mustached bat (Pteronotus parnellii). These subdivisions provide a reference for structural, physiological, connectional, and neurochemical work. Most nuclei recognized in other mammals exist in the mustached bat, although the relative volume of the three divisions was species specific. The ventral division contains medium-sized neurons and a few smaller cells and is well developed. Neurons in the lateral part lie in regularly aligned rows corresponding to the laminae in Golgi material; in the medial part, these laminae are obscured by fibers. The dorsal division has at least four nuclei, each with a unique cytoarchitecture and myeloarchitectonic organization. The supraGeniculate nucleus is prominent and has many large radiate neurons. Cells in the superficial dorsal nucleus have weekly laminated dendrites, while dorsal nucleus neurons have spherical dendritic fields. There is a wide range of neuropil patterns within the dorsal division. The supraGeniculate nucleus has thick myelinated axons, while the fibers in the superficial and dorsal nuclei are much thinner. The rostral pole nucleus becomes prominent in the anterior one-half of the auditory thalamus; its architectonic affiliation is equivocal, and connectional and immunocytochemical studies suggest that it may belong to the dorsal division. The medial division is one nucleus with many types of neurons, and it has coarse axons without laminar orientation. It is the smallest of the divisions and is present throughout the medial Geniculate complex, except at the caudal tip and at the rostral pole. Many features of medial Geniculate Body organization evident in other mammals are recognized in the mustached bat. These include a prominent ventral division, some of whose neurons have a laminar organization, and a comparatively small medial division that is devoid of fibrodendritic laminae. Other features, such as the presence of a large rostral pole nucleus, whose homologue in other species is uncertain, or the sparse number or small cells that may participate in local circuits, set it apart from carnivores and primates and suggest that there are species specific patterns of medial Geniculate Body organization.
Y Tamai - One of the best experts on this subject based on the ideXlab platform.
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“Ventral” area in the rat auditory cortex: A major auditory field connected with the dorsal division of the medial Geniculate Body
Neuroscience, 2006Co-Authors: Tomohiro Donishi, Akihisa Kimura, Keiichiro Okamoto, Y TamaiAbstract:Abstract The rat auditory cortex is made up of multiple auditory fields. A precise correlation between anatomical and physiological areal extents of auditory fields, however, is not yet fully established, mainly because non-primary auditory fields remain undetermined. In the present study, based on thalamocortical connection, electrical stimulation and auditory response, we delineated a non-primary auditory field in the cortical region ventral to the primary auditory area and anterior auditory field. We designated it as “ventral” area after its relative location. At first, based on anterograde labeling of thalamocortical projection with biocytin, ventral auditory area was delineated as a main cortical terminal field of thalamic afferents that arise from the dorsal division of the medial Geniculate Body. Cortical terminal field (ventral auditory area) extended into the ventral margin of temporal cortex area 1 (Te1) and the dorsal part of temporal cortex area 3, ventral (Te3V), from 3.2–4.6 mm posterior to bregma. Electrical stimulation of the dorsal division of the medial Geniculate Body; evoked epicortical field potentials confined to the comparable cortical region. On the basis of epicortical field potentials evoked by pure tones, best frequencies were further estimated at and around the cortical region where electrical stimulation of the dorsal division of the medial Geniculate Body evoked field potentials. Ventral auditory area was found to represent frequencies primarily below 15 kHz, which contrasts with our previous finding that the posterodorsal area, the other major recipient of the dorsal division of the medial Geniculate Body; projection, represents primarily high frequencies (>15 kHz). The posterodorsal area is thought to play a pivotal role in auditory spatial processing [Kimura A, Donishi T, Okamoto K, Tamai Y (2004) Efferent connections of “posterodorsal” auditory area in the rat cortex: implications for auditory spatial processing. Neuroscience 128:399–419]. The ventral auditory area, as the other main cortical region that would relay auditory input from the dorsal division of the medial Geniculate Body to higher cortical information processing, could serve an important extralemniscal function in tandem with the posterodorsal area. The results provide insight into structural and functional organization of the rat auditory cortex.
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topography of projections from the primary and non primary auditory cortical areas to the medial Geniculate Body and thalamic reticular nucleus in the rat
Neuroscience, 2005Co-Authors: Akihisa Kimura, Tomohiro Donishi, Keiichiro Okamoto, Y TamaiAbstract:The functional significance of parallel and redundant information processing by multiple cortical auditory fields remains elusive. A possible function is that they may exert distinct corticofugal modulations on thalamic information processing through their parallel connections with the medial Geniculate Body and thalamic reticular nucleus. To reveal the anatomical framework for this function, we examined corticothalamic projections of tonotopically comparable subfields in the primary and non-primary areas in the rat auditory cortex. Biocytin was injected in and around cortical area Te1 after determining best frequency at the injection site on the basis of epicortical field potentials evoked by pure tones. The rostral part of area Te1 (primary auditory area) and area temporal cortex, area 2, dorsal (Te2D) (posterodorsal auditory area) dorsal to the caudal end of area Te1, which both exhibited high best frequencies, projected to the ventral zone of the ventral division of the medial Geniculate Body. The caudal end of area Te1 (auditory area) and the rostroventral part of area Te1 (a part of anterior auditory field), which both exhibited low best frequencies, projected to the dorsal zone of the ventral division of the medial Geniculate Body. In contrast to the similar topography in the projections to the ventral division of the medial Geniculate Body, collateral projections to the thalamic reticular nucleus terminated in the opposite dorsal and ventral zones of the lateral and middle tiers of the nucleus in each pair of the tonotopically comparable cortical subfields. In addition, the projections of the non-primary cortical subfields further arborized in the medial tier of the thalamic reticular nucleus. The results suggest that tonotopically comparable primary and non-primary subfields in the auditory cortex provide corticofugal excitatory effects to the same part of the ventral division of the medial Geniculate Body. On the other hand, corticofugal inhibition via the thalamic reticular nucleus may operate in different parts of the ventral division of the medial Geniculate Body or different thalamic nuclei. The primary and non-primary cortical auditory areas are presumed to subserve distinct gating functions for auditory attention.
David T Larue - One of the best experts on this subject based on the ideXlab platform.
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gabaergic organization of the cat medial Geniculate Body
The Journal of Comparative Neurology, 1999Co-Authors: Camillan L Huang, David T Larue, Jeffery A WinerAbstract:A study of neurons and processes (puncta) immunolabeled by antibodies to ! -aminobutyric acid (GABA) or glutamic acid decarboxylase was undertaken in the medial Geniculate Body of the adult cat. The proportion and types of GABAergic cells were determined with high resolution methods, including postembbedding immunocytochemistry on semithin plastic sections. A second goal was to draw parallels and differences between the auditory thalamus and other thalamic nuclei. Finally, the types of GABAergic puncta and their concentration in the three major subdivisions of the medial Geniculate Body were analyzed. The results were that (1) each division had many GABAergic neurons, averaging approximately 26% of the neuronal population; (2) the ventral division had the highest proportion of these cells (33%), the medial division the fewest (18%), and the dorsal division was intermediate (26%); (3) there was a gradient in the proportion of GABAergic neurons, i.e., the ventral and medial division values increased caudorostrally, whereas the value in the dorsal division declined; (4) the predominant GABAergic cell type in each division was a small neuron with a soma approximately 10‐12 µm in diameter; (5) a small population of much larger GABAergic neurons was present mainly in the dorsal division; (6) in addition to the fine, granular puncta in each division, a type of giant GABAergic puncta was found only in the dorsal division nuclei. The results obtained with the two antibodies were essentially identical. These findings suggest a structural basis for qualitative differences in the distribution of GABAergic processing within the medial Geniculate complex. The GABAergic arrangement in the ventral division was stereotyped, with only one type of putative GABAergic interneuron, and the puncta were correspondingly homogeneous. In contrast, the dorsal division had two types of GABAergic neurons, and the giant GABAergic puncta represent a new substrate for inhibitory interactions. The medial division also had more than one type of GABAergic neuron and a slightly lower concentration of puncta. These qualitative and quantitative distinctions suggest a morphologic basis for possible differences in inhibitory processing among medial
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neural architecture of the rat medial Geniculate Body
Hearing Research, 1999Co-Authors: Jeffery A Winer, Jack B Kelly, David T LarueAbstract:The rat medial Geniculate Body was subdivided using Nissl preparations to establish nuclear boundaries, with Golgi-Cox impregnations to identify projection and local circuit neurons, and in fiber stained material to delineate the fiber tracts and their distribution. Three divisions were recognized (ventral, dorsal and medial): the first two had subdivisions. The ventral division had lateral and medial parts. The main cell type had bushy tufted dendrites which, with the afferent axons, formed fibrodendritic laminae oriented from dorso-lateral to ventro-medial; such laminae were not as regular medially, in the ovoid nucleus. The dorsal division contained several nuclei (dorsal superficial, dorsal, deep dorsal, supraGeniculate, and ventrolateral) and neurons with radiating or bushy dendrites; the nuclear subdivisions differed in the concentration of one cell type or another, and in packing density. A laminar organization was present only in the dorsal superficial nucleus. Medial division neurons were heterogeneous in size and shape, ranging from tiny cells to magnocellular neurons; the various cell types intermingled. so that no further subdivision could be made. This parcellation scheme was consistent with, and supported by, the findings from plastic embedded or fiber stained material. There were very few small neurons with locally ramifying axons and which could perform an intrinsic role like that of Golgi type II cells. Their rarity was consistent with the small number of such profiles in plastic embedded or Nissl material and the few GABAergic medial Geniculate Body neurons seen in prior immunocytochemical work. While similar neuronal types and nuclear subdivisions are recognized in the rat and cat, there may be major interspecific differences with regard to interneuronal organization in the auditory thalamus whose functional correlates are unknown.
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gabaergic feedforward projections from the inferior colliculus to the medial Geniculate Body
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jeffery A Winer, David T Larue, R Saint L Marie, Douglas L. OliverAbstract:Abstract A novel and robust projection from gamma-aminobutyric acid-containing (GABAergic) inferior colliculus neurons to the media] Geniculate Body (MGB) was discovered in the cat using axoplasmic transport methods combined with immunocytochemistry. This input travels with the classical inferior colliculus projection to the MGB, and it is a direct ascending GABAergic pathway to the sensory thalamus that may be inhibitory. This bilateral projection constitutes 10-30% of the neurons in the auditory tectothalamic system. Studies by others have shown that comparable input to the corresponding thalamic visual or somesthetic nuclei is absent. This suggests that monosynaptic inhibition or disinhibition is a prominent feature in the MGB and that differences in neural circuitry distinguish it from its thalamic visual and somesthetic counterparts.
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evolution of gabaergic circuitry in the mammalian medial Geniculate Body
Proceedings of the National Academy of Sciences of the United States of America, 1996Co-Authors: Jeffery A Winer, David T LarueAbstract:Abstract Many features in the mammalian sensory thalamus, such as the types of neurons, their connections, or their neurotransmitters, are conserved in evolution. We found a wide range in the proportion of gamma-aminobutyric acidergic (GABAergic) neurons in the medial Geniculate Body, from <1% (bat and rat) to 25% or more (cat and monkey). In the bat, some medial Geniculate Body subdivisions have no GABAergic cells. Species-specific variation also occurs in the somesthetic ventrobasal complex. In contrast, the lateral Geniculate Body of the visual system has about the same proportion of GABAergic cells in many species. In the central auditory pathway, only the medial Geniculate Body shows this arrangement; the relative number of GABAergic cells in the inferior colliculus and auditory cortex is similar in each species. The range in the proportion of GABAergic neurons suggests that there are comparative differences in the neural circuitry for thalamic inhibition. We conclude that the number of GABAergic neurons in thalamic sensory nuclei may have evolved independently or divergently in phylogeny. Perhaps these adaptations reflect neurobehavioral requirements for more complex, less stereotyped processing, as in speech-like communication.
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projections of physiologically defined subdivisions of the inferior colliculus in the mustacbed bat targets in the medial Geniculate Body and extrathalamic nuclei
The Journal of Comparative Neurology, 1994Co-Authors: Jeffrey J Wenstrup, David T Larue, Jeffery A WinerAbstract:This study examined the output of the central nucleus of the inferior colliculus to the medial Geniculate Body and other parts of the nervous system in the mustached bat (Pteronotus parnellii). Small deposits of anterograde tracers (horseradish peroxidase, [3H]leucine, Phaseolus vulgaris leucoagglutinin, wheat germ agglutinin conjugated to horseradish peroxidase, or biocytin) were made at physiologically defined sites in the central nucleus representing major components of the bat's echolocation signal. The topography, frequency specificity, and axonal morphology of these outputs were studied. The medial Geniculate Body was a major target of inferior collicular neurons, with three distinct input patterns. The projection to the ventral division was tonotopically organized, but had a relatively sparse contribution from neurons representing frequency modulated components of the biosonar pulse. The second input was to the rostral medial Geniculate Body, in which projections from inferior collicular neurons representing constant frequency sonar components were separated from those representing frequency modulated components. A third input was to the supraGeniculate nucleus, which received strong, topographically arranged projections. Inputs to the dorsal nucleus and medial division were also observed. Extrathalamic regions receiving input included the pontine gray, external nucleus of the inferior colliculus, pericollicular tegmentum, nucleus of the brachium of the inferior colliculus, and pretectum. These central nucleus projections differed in organization and the structure of axon terminals, suggesting different physiological influences on their target nuclei. These results demonstrate that the central nucleus has divergent projections to various sensory and premotor nuclei, besides its well-established projection to the medial Geniculate Body. © 1994 Wiley-Liss, Inc.