Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Using an antibody raised against a purified chick duodenal vitamin D-dependent calcium-binding protein, the presence and distribution of calbindin has been studied immunohistochemically in the habenular ganglia of the dogfish. In the more developed left ganglion, a positive reaction was clearly observed in the neurons of the medial nucleus, whereas in the lateral nucleus, only some scarce, hardly immunostained cells appeared. In the neurons of the right habenula however, no immuno-reactivity was observed. The distribution of vitamin D-dependent calcium-binding protein in the dogfish habenulae is therefore asymmetrical. This may be due to differences in the neuronal activity between the two ganglia.
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PMID:Asymmetric distribution of calbindin-D28K in the ganglia habenulae of an elasmobranch fish. 234 31

The distribution of the calcium binding protein, calretinin (CR) has been investigated immunohistochemically in the cerebral cortex of albino rats by light- and electron microscopy. At the light microscopical level the pattern of CR-immunoreactivity (ir) appeared very similar in all regions of the rat cerebral cortex. CR-immunoreactive cells were found sparsely in layer I to layer VI, and frequently also in the white matter of the corpus callosum. All CR-ir neurons revealed morphological characteristics of local interneurons. The calretinin positive interneurons could be grouped according to their laminar occurrence, dendritic arborization and the soma size into 5 cell type classes. Quantitative measurements were performed only in the visual cortex. CR-ir neurons were more frequent in the superficial layers II and III. In all other layers, CR-ir cells are sparsely distributed with no preferential laminar localization. At the electron microscopical level, CR-ir axonal boutons formed frequently symmetrical axo-dendritic contacts. In all animals we observed CR-ir axons forming also synaptses of asymmetrical type. In summary calretinin labelled an interneuronal subpopulation of the rat cerebral cortex, which seemed not to overlap in its distribution and labelled structures to those, containing the related calcium binding proteins parvalbumin and calbindin D-28k.
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PMID:The calcium-binding protein calretinin is localized in a subset of interneurons in the rat cerebral cortex: a light and electron immunohistochemical study. 837 59

The cellular and synaptic localization of immunoreactivity for the N-methyl-D-aspartate (NMDA) receptor subunit, NMDAR1, was investigated in inferotemporal and prefrontal association neocortices of monkeys and humans. In all monkey association areas examined, the laminar distribution patterns of NMDAR1 immunoreactivity were similar, and characterized by predominant pyramidal-like neuronal labeling in layers II, III, V and VI and a dense neuropil labeling consisting of intensely stained puncta and fine-caliber processes present throughout layers I-III, and V-VI. Layer IV, in contrast, contained only very lightly immunostained neurons which mostly lacked extensive dendritic staining. The laminar distribution of NMDAR1 immunolabeling in human association cortex was similar to that observed in monkeys. Electron microscopy of monkey areas 46 and TE1 confirmed that intensely immunoreactive asymmetrical postsynaptic densities were present throughout all cell-dense layers of prefrontal and inferotemporal association cortex. Quantitative analyses of the laminar proportions of immunoreactive synapses demonstrated that in both areas examined, the percentages of immunolabeled synapses were mostly similar across superficial layers, layer IV and infragranular layers. Finally, quantitative double-labeling immunofluorescence for non-NMDA receptor subunits or calcium-binding proteins demonstrated that virtually all GluR2/3 or GluR5/6/7-immunoreactive neurons were also labeled for NMDAR1, while regionally-specific subsets of parvalbumin-, calbindin- and calretinin-immunoreactive neurons were co-labeled. These data indicate that in primate association cortex, NMDA receptors are heterogeneously distributed to subsets of functionally distinct types of neurons and subsets of excitatory synapses, suggesting a critical and highly specific role in mediating the activity of excitatory connectivity which converges on cortical association areas.
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PMID:Quantitative localization of NMDAR1 receptor subunit immunoreactivity in inferotemporal and prefrontal association cortices of monkey and human. 913 25

Previous immunocytochemical studies in the cerebral cortex of various species have shown that the calcium-binding protein calretinin (CR) labels specific subpopulations of nonspiny nonpyramidal cells (interneurons). The present study attempts to characterize morphologically and chemically the microcircuitry of CR-immunoreactive (CR-ir) neurons in the human temporal neocortex. Postembedding immunocytochemistry for CR and GABA and combination immunocytochemistry for CR and nonphosphorylated neurofilament protein (NPNFP) or for CR and the calcium-binding proteins parvalbumin (PV) and calbindin (CB) showed CR multiterminal endings frequently innervating the distal apical dendrite or the cell body and proximal dendrites of NPNFP-ir or CB-ir pyramidal cells, respectively. Cell bodies of interneurons immunoreactive for CB or PV were innervated only occasionally by CR multiterminal endings, whereas certain GABA neurons were surrounded by them. Furthermore, CR-ir axon terminals formed either symmetrical (the majority) or asymmetrical synapses with a variety of postsynaptic elements. These results indicate that different subpopulations of CR interneurons exist that are specialized for selective innervation of somatic or dendritic regions of certain pyramidal and nonpyramidal neurons.
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PMID:Synaptic connections of calretinin-immunoreactive neurons in the human neocortex. 918 52

Previous studies have demonstrated formation of recurrent excitatory circuits between sprouted mossy fibers and granule cell dendrites in the inner molecular layer of the dentate gyrus (9, 28, 30). In addition, there is evidence that inhibitory nonprincipal cells also receive an input from sprouted mossy fibers (39). This study was undertaken to further characterize possible target cells for sprouted mossy fibers, using immunofluorescent staining for different calcium-binding proteins in combination with Timm histochemical staining for mossy fibers. Rats were injected intraperitoneally with kainic acid in order to induce epileptic convulsions and mossy fiber sprouting. After 2 months survival, hippocampal sections were immunostained for parvalbumin, calbindin D28k, or calretinin followed by Timm-staining. Under a fluorescent microscope, zinc-positive mossy fibers in epileptic rats were found to surround parvalbumin-containing neurons in the granule cell layer and to follow their dendrites, which extended toward the molecular layer. In addition, dendrites of calbindin D28k-containing cells were covered by multiple mossy fiber terminals in the inner molecular layer. However, the calretinin-containing cell bodies in the granule cell layer did not receive any contacts from the sprouted fibers. Electron microscopic analysis revealed that typical Timm-positive mossy fiber terminals established several asymmetrical synapses with the soma and dendrites of nonpyramidal cells within the granule cell layer. These results provide direct evidence that, in addition to recurrent excitatory connections, inhibitory circuitries, especially those responsible for the perisomatic feedback inhibition, are formed as a result of mossy fiber sprouting in experimental epilepsy.
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PMID:Characterization of target cells for aberrant mossy fiber collaterals in the dentate gyrus of epileptic rat. 927 41

The present study analyzed three-dimensional structural features and synaptic contacts of morphologically and chemically identified calbindin D28K-immunoreactive neurons in the glomerular layer of the rat main olfactory bulb by means of combined confocal laser scanning light microscopy, high-voltage electron microscopy and electron microscopic serial section/three-dimensional reconstruction. Most of calbindin D28K-immunoreactive neurons were identified as the periglomerular cell type by combined high-voltage electron microscopic and confocal laser scanning light microscopic observations, and the minority were the short-axon cell type and others. The combined confocal laser scanning light microscopic and electron microscopic study revealed that the calbindin D28K-immunoreactive neurons exhibited unique synaptic contact patterns; they received asymmetrical synapses from presumed mitral/tufted dendrites and made conversely symmetrical synapses with them. About 30% of asymmetrical postsynaptic sites and about 40% of symmetrical presynaptic sites formed reciprocal pairs of synapses. Calbindin D28K-immunoreactive dendrites and somata also received synapses from GABA-like-immunoreactive profiles containing numerous pleomorphic, and a few dense-cored, vesicles. On the other hand, surprisingly, calbindin D28K-immunoreactive neurons had almost no synaptic contacts from olfactory nerve terminals. The present study clearly revealed that calbindin D28K-immunoreactive neurons are a type of periglomerular cell involving unique synaptic contacts that have not been reported so far, and thus indicated that so-called periglomerular cells should be heterogeneous in their synaptic connections as well as in their chemical and structural features.
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PMID:Chemically defined neuron groups and their subpopulations in the glomerular layer of the rat main olfactory bulb: III. Structural features of calbindin D28K-immunoreactive neurons. 951 68

The supramammillary nucleus, collecting information about the physiological state of the animal, innervates medial septal neurons that are involved in the generation of hippocampal theta activity. Here we demonstrate that septal neurons located in an area bordering the medial and lateral septal nucleus project back to the supramammillary nucleus, and most of these cells contain calretinin, calbindin or both. GABA-immunoreactive boutons of these neurons (60%) form symmetrical synapses, whereas the remaining GABA-negative terminals form asymmetrical synapses (40%) with their supramammillary targets. We hypothesize that the septosupramammillary feedback, because of the specific location of its parent cells, carries information about the activity of theta generator cells in the medial septum and supramammillary nucleus, as well as about the resulting theta activity in the hippocampus.
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PMID:Dual projection from the medial septum to the supramammillary nucleus in the rat. 973 9

The morphology, distribution, and ultrastructural features of calbindin-D28k-immunoreactive neurons and fibers in the cortical regions of the lizard Psammodromus algirus, considered homologues to the mammalian hippocampal formation, were analyzed by using the peroxidase anti-peroxidase technique at the light and electron microscopic level. On the basis of staining properties and localization, two distinct populations of calbindin-D28k-immunoreactive neurons were observed in both the medial and dorsal cortices. Those located in the cell layer, namely principal neurons, were weakly immunostained, whereas a number of Golgi-like stained neurons were observed in plexiform layers. Double immunocytochemistry showed that all calbindin immunoreactive neurons in the deep plexiform layers were also gamma-aminobutyric acid immunoreactive. We consider them as a population of nonprincipal neurons different from those containing the calcium-binding proteins parvalbumin and calretinin. Two types of immunoreactive Boutons were revealed by electron microscopy on the basis of the synaptic specialization: Boutons making asymmetrical synapses were generally smaller in size and contacted on small dendritic profiles or cell bodies, whereas larger boutons established symmetrical synapses mainly on dendritic shafts. We propose that the first type of boutons arises from principal neurons and that the second type arises from nonprincipal ones. Finally, the staining pattern, localization, and the circuit in which nonprincipal calbindin-immunoreactive neurons and other neurochemically defined neurons could be involved in cortical regions of Psammodromus are compared with those of mammalian hippocampus.
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PMID:Calbindin-D28k in cortical regions of the lizard Psammodromus algirus. 1002 96

The least known aspect of the functional architecture of hippocampal microcircuits is the quantitative distribution of synaptic inputs of identified cell classes. The complete dendritic trees of functionally distinct interneuron types containing parvalbumin (PV), calbindin D(28k) (CB), or calretinin (CR) were reconstructed at the light microscopic level to describe their geometry, total length, and laminar distribution. Serial electron microscopic reconstruction and postembedding GABA immunostaining was then used to determine the density of GABA-negative asymmetrical (excitatory) and GABA-positive symmetrical (inhibitory) synaptic inputs on their dendrites, somata, and axon initial segments. The total convergence and the distribution of excitatory and inhibitory inputs were then calculated using the light and electron microscopic data sets. The three populations showed characteristic differences in dendritic morphology and in the density and distribution of afferent synapses. PV cells possessed the most extensive dendritic tree (4300 microm) and the thickest dendrites. CR cells had the smallest dendritic tree (2500 microm) and the thinnest shafts. The density of inputs as well as the total number of excitatory plus inhibitory synapses was several times higher on PV cells (on average, 16,294) than on CB (3839) or CR (2186) cells. The ratio of GABAergic inputs was significantly higher on CB (29.4%) and CR (20.71%) cells than on PV cells (6.4%). The density of inhibitory terminals was higher in the perisomatic region than on the distal dendrites. These anatomical data are essential to understand the distinct behavior and role of these interneuron types during hippocampal activity patterns and represent fundamental information for modeling studies.
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PMID:Total number and ratio of excitatory and inhibitory synapses converging onto single interneurons of different types in the CA1 area of the rat hippocampus. 1055 16

Synapses of intraglomerular processes of tyrosine hydroxylase-immunoreactive neurons in the rat main olfactory bulb were examined by electron microscopic immunocytochemistry. Prominent characteristics of intraglomerular synapses of tyrosine hydroxylase-immunoreactive elements were that the vast majority (about 80%) of their synaptic inputs were asymmetrical synapses from olfactory nerve terminals and, though far smaller in proportion, one half of the remaining were asymmetrical synapses from mitral/tufted cell dendrites and the other half were symmetrical synapses from gamma-aminobutyric acid-like immunoreactive elements. So far, we have observed no typical reciprocal synapses between tyrosine hydroxylase-immunoreactive processes and mitral/tufted dendrites; however, we have often identified serial synapses; that is, asymmetrical synapses from olfactory nerve terminals or mitral/tufted cell dendrites to tyrosine hydroxylase-immunoreactive processes, and then symmetrical synapses from the latter to different mitral/tufted cell dendrites. These synaptic connections of tyrosine hydroxylase-immunoreactive neurons were very different from those of Calbindin-D(28k)-immunoreactive neurons, which received no synaptic contact directly from olfactory nerve terminals but formed reciprocal synapses with mitral/tufted cells as we analysed previously.Thus, our present and previous electron microscopic studies combined with confocal laser scanning light microscopy clearly indicated for the first time the heterogeneity of periglomerular neurons, not only in their chemical and morphological features, but also in their synaptic organization in the olfactory glomerulus.
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PMID:Chemically defined neuron groups and their subpopulations in the glomerular layer of the rat main olfactory bulb--IV. Intraglomerular synapses of tyrosine hydroxylase-immunoreactive neurons. 1106 32


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