Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Calretinin and calbindin-D28k are two calcium-binding proteins which are present in separate populations of interneurons in cerebral cortex and hippocampus. To identify these cells with the populations expressing different transmitters, two-colour immunofluorescence was done with antibodies against the calcium-binding proteins plus antibodies against vasoactive intestinal peptide (VIP), somatostatin (SRIF), or gamma-aminobutyric acid (GABA). In neocortex, calretinin is partially co-localized with VIP (especially in the deeper layers) and is not co-localized with SRIF. Calbindin is largely co-localized with SRIF, and not with VIP. Both calretinin and calbindin are partially co-localized with GABA. In piriform and entorhinal cortex, the patterns resemble those in neocortex. In hippocampus, preliminary data indicate greater heterogeneity, especially in the ventral part; at least a few double-positive cells are present for every combination of calcium-binding protein and neuropeptide. These results expand the known diversity of local-circuit neurons in cortical regions.
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PMID:Immunohistochemical markers in rat cortex: co-localization of calretinin and calbindin-D28k with neuropeptides and GABA. 135 60

Postsynaptic targets of the GABAergic septohippocampal and the serotonergic raphe-hippocampal pathways were studied using anterograde tracing with Phaseolus vulgaris leucoagglutinin combined with pre- and postembedding immunocytochemistry in the rat. Two types of afferents were labeled in the hippocampus and dentate gyrus from the medial septum-diagonal band of Broca complex, one with large diameter varicosities and another with smaller terminals. The former type was shown to be immunoreactive for gamma-aminobutyric acid (GABA), and to innervate predominantly GABA-immunoreactive interneurons. Subsequently, these target interneurons were demonstrated to include all subpopulations of GABAergic cells which could be visualized by antisera against parvalbumin, calbindin D28k, calretinin, cholecystokinin, somatostatin, neuropeptide Y and vasoactive intestinal polypeptide. These types of interneurons have different afferent and efferent connections, and thus participate in different inhibitory processes in the hippocampal formation. The other subcortical pathway, the serotonergic projection from the median raphe nucleus, was also shown to establish synapses predominantly with GABAergic interneurons both in the hippocampus and in the dentate gyrus. In contrast to the septohippocampal projection, this pathway did not innervate all types of GABAergic neurons. They selected a particular subpopulation, i.e. those which contain calbindin D28k, and ignored those which contained parvalbumin or the other neurochemical markers. This suggests a strong functional specialization among local inhibitory circuits, as well as among the subcortical afferents originating in the septum and raphe. These findings suggest that a mechanism by which numerically small afferent pathways may have a profound global effect on the electrical activity of the hippocampal formation is the selective innervation of local interneurons. These GABAergic inhibitory cells, in turn, control the activity of large populations of principal cells. The level of GABAergic inhibition determines the degree of population synchrony and influences N-methyl-D-aspartate receptor-mediated epileptiform burst-firing. Thus, the specific subcortical modulation of hippocampal inhibitory circuits may also have fundamental implications for epileptogenesis.
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PMID:GABAergic septal and serotonergic median raphe afferents preferentially innervate inhibitory interneurons in the hippocampus and dentate gyrus. 136 33

It is well established that acetylcholine is a neurotransmitter at several distinct sites in the mammalian enteric nervous system. However, identification of the cholinergic neurons has not been possible due to an inability to selectively label enteric cholinergic neurons. In the present study an immunohistochemical method has been developed to localize choline acetyltransferase, the synthetic enzyme for acetylcholine, in order that cholinergic neurons can be visualized. The morphology, neurochemical coding and projections of cholinergic neurons in the guinea-pig small intestine were determined using double-labelling immunohistochemistry. These experiments have revealed that many myenteric neurons are cholinergic and that they can be distinguished by their specific combinations of immunoreactivity for neurochemicals such as calretinin, neurofilament protein triplet, substance P, enkephalin, somatostatin, 5-hydroxytryptamine, vasoactive intestinal peptide and calbindin. On the basis of their previously described projections, functional roles could be attributed to each of these populations. The identified cholinergic neurons are: motorneurons to the longitudinal muscle (choline acetyltransferase/calretinin); motorneurons to the circular muscle (choline acetyltransferase/neurofilament triplet protein/substance P, choline acetyltransferase/substance P and choline acetyltransferase alone); orally directed interneurons in the myenteric plexus (choline acetyltransferase/calretinin/enkephalin); anally directed interneurons in the myenteric plexus (choline acetyltransferase/somatostatin, choline acetyltransferase/5-hydroxytryptamine, choline acetyltransferase/vasoactive intestinal peptide); secretomotor neurons to the mucosa (choline acetyltransferase/somatostatin); and sensory neurons mediating myenteric reflexes (choline acetyltransferase/calbindin). This information provides a unique opportunity to identify functionally distinct populations of cholinergic neurons and will be of value in the interpretation of physiological and pharmacological studies of enteric neuronal circuitry.
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PMID:Immunohistochemical identification of cholinergic neurons in the myenteric plexus of guinea-pig small intestine. 172 93

The arrangement of the enteric nerve plexuses, and the distributions and projections of chemically specified neurons in the proximal colon of the guinea-pig were studied. The neural plexuses were examined using immunoreactivity to neuron specific enolase, and individual subpopulations were studied using antibodies raised against vasoactive intestinal peptide (VIP), substance P (SP), enkephalin, neuropeptide Y (NPY), gastrin releasing peptide (GRP), galanin, somatostatin, calbindin and calretinin. Nitric oxide producing neurons were studied using NADPH diaphorase histochemistry. The myenteric and submucous plexuses were not uniform around the entire circumference; at the mesenteric aspect of the colon there was almost no longitudinal muscle and the circular muscle was unusually thick and cord-like. In this region there was no tertiary plexus of fibres, and the ganglia of the myenteric and submucous plexuses were elongated in the direction of the circular muscle. Neuronal pathways within the antimesenteric aspect of the colon were investigated using nerve lesioning procedures. VIP, GRP, galanin, calbindin and NADPH diaphorase containing neurons lay in anally projecting pathways within the myenteric plexus, while enkephalin and somatostatin appeared in orally projecting nerve pathways. Few NPY immunoreactive nerve cells were found in the myenteric plexus of the proximal colon. The longitudinal muscle was innervated with VIP, SP, enkephalin and NADPH diaphorase containing fibres. The circular muscle was innervated by axons containing all substances investigated except NPY. Galanin, NPY, somatostatin and VIP fibres, all particularly dense in the mucosa, largely arose from nerve cell bodies in the submucous plexus. The results of the present study indicate that chemically specified neuronal populations in the proximal colon of the guinea-pig are more similar to the distal colon than the ileum, but that neuro-chemical and anatomical differences exist between the proximal and distal colon.
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PMID:Immunohistochemical analysis of neurons and their projections in the proximal colon of the guinea-pig. 751 May 7

GABAergic interneurons in the rat frontal cortex were subdivided on the basis of immunoreactivity for calcium binding proteins, neuropeptides and nitric oxide synthase, using double immunofluorescence and mirror image immunohistochemical methods. The results indicate that in this region of the neocortex there are at least three distinct subpopulations of local circuit neurons. The first subgroup consists of parvalbumin-immunoreactive cells. Those do not contain neuropeptide, calretinin or nitric oxide synthase immunoreactivity. A substantial number of parvalbumin-immunoreactive cells in layer II/III were also immunoreactive for calbindin D28k. The second subgroup consists of cells immunoreactive for calretinin. Most were usually immunoreactive for vasoactive intestinal polypeptide as well, but a few cells in layer II/III were immunoreactive for one or the other only. Calretinin-immunoreactive cells do not colocalize parvalbumin, somatostatin or nitric oxide synthase, and only a few colocalize calbindin D28k. The third subgroup consists of cells most of which contain somatostatin, and is entirely separate from the parvalbumin- and calretinin-immunoreactive populations. There was substantial colocalization of somatostatin and calbindin D28k and of somatostatin and neuropeptide Y. Some somatostatin-immunoreactive cells showed nitric oxide synthase immunoreactivity. All of the populations of immunoreactive cells examined in the present study also showed GABA immunoreactivity. About 10% of calbindin D28k-immunoreactive cells and all of those strongly stained for calbindin D28k in layer II/III showed GABA immunoreactivity. Most calbindin D28k-positive cells in deep layers also showed GABA immunoreactivity. These results support that almost all calbindin D28k-immunoreactive non-pyramidal cells are probably GABAergic.
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PMID:Three distinct subpopulations of GABAergic neurons in rat frontal agranular cortex. 752 7

Neurons of the supramammillary nucleus are known to fire phase-locked to hippocampal theta rhythm. Stimulation of this area induces theta activity in the hippocampus via the medial septum and facilitates perforant pathway stimulation-evoked population spikes in the dentate gyrus even if the medial septum is inactivated. This latter effect was suggested to be due to a direct inhibitory input from the supramammilary nucleus to hippocampal nonpyramidal cells resulting in disinhibition. In the present study, using anterograde tracing with Phaseolus vulgaris leucoagglutinin, we aimed to identify the types of neurons innervated by the supramammillary projection in the dentate gyrus and Ammons horn, with particular attention to the presumed postsynaptic inhibitory neurons, which may mediate the proposed disinhibitory action. Double-immunostaining for the tracer and different neuropeptides (somatostatin, cholecystokinin, neuropeptide Y) or calcium binding proteins (calretinin, parvalbumin, calbindin D28K) present in different subpopulations of interneurons revealed no multiple contacts between supramammillary afferents and labeled inhibitory cells at the light microscopic level. Furthermore, postembedding immunostaining of electron microscopic sections for GABA demonstrated that none of the 68 PHAL-labeled supramammillary boutons examined and none of their postsynaptic targets were immunoreactive for the inhibitory neurotransmitter. We conclude, therefore, that most if not all postsynaptic targets of the supramammillary projection are principal cells both in the dentate gyrus and in the CA2-CA3a subfields. This suggests that a mechanism other than disinhibition is responsible for the facilitatory effect of this pathway on hippocampal evoked activity.
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PMID:Principal cells are the postsynaptic targets of supramammillary afferents in the hippocampus of the rat. 753 Oct 93

The aim of this study was to investigate the neurochemical coding of myenteric neurons in the guinea pig gastric corpus by using immunohistochemical methods. Antibodies and antisera against calbindin (CALB), calretinin (CALRET), choline acetyltransferase (ChAT), calcitonin gene-related peptide (CGRP), dopamine beta-hydroxylase (DBH), beta-endorphin (ENK), neuropeptide Y (NPY), neuron-specific enolase (NSE), nitric oxide synthase (NOS), protein gene product 9.5 (PGP), parvalbumin (PARV), serotonin (5-HT), somatostatin (SOM), substance P (SP), tyrosine hydroxylase (TH), and vasoactive intestinal peptide (VIP) were used. Double- and triple-labeling studies revealed colocalization of certain transmitters and enabled the identification of distinct subpopulations of gastric enteric neurons. NPY/VIP/NOS/ENK were present in 28% of all neurons, whereas 11% had NPY/VIP/DBH/ChAT; NOS-only neurons made up 2% of the population. The combination SP/ChAT/ENK occurred in 21% of the population, whereas SP/ChAT/ENK/CALRET and SP/CHAT/SOM/ +/- CALRET was identified in 5% and 6% of all cells, respectively. 5-HT-containing neurons comprised 2% of all cells and could be further classified by the presence of additional antigens as 5-HT/SP/(ChAT) or 5-HT/VIP/(ChAT). Approximately 21% of all neurons contained only ChAT with no additional antigen present and are referred to as ChAT/-. Gastric myenteric ganglion cells were not immunoreactive for CALB, PARV, CGRP, or TH. The results of this study indicate that gastric myenteric neurons can be characterized on the basis of different chemical coding. Neurochemical coding of corpus myenteric neurons revealed some similarities and significant differences in comparison with other regions of the gut. These differences might reflect adaptation of enteric nerves according to regional specialization and the distinct functions of the proximal stomach as a gastric reservoir.
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PMID:Neurochemical coding of enteric neurons in the guinea pig stomach. 753 52

We have compared the cellular organization of GABAergic interneurons between frontal cortex and neostriatum of rats by immunohistochemistry for calcium-binding proteins, somatostatin and nitric oxide synthase (NOS). GABAergic interneurons in both neocortex and neostriatum could be divided into three separate populations containing parvalbumin, somatostatin, or calretinin. NOS cells were considered to be GABAergic and belong to somatostatin cells in both structures. Distributions of calbindin D28k in three classes of interneurons were different among neocortical layers and neostriatum.
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PMID:Three classes of GABAergic interneurons in neocortex and neostriatum. 753 6

Light- and electron-microscopic studies were used to investigate connections between specific subgroups of neurons in the myenteric plexus of the guinea-pig small intestine. Inputs to two classes of calretinin-immunoreactive (IR) nerve cells, longitudinal muscle motor neurons and ascending interneurons, were examined. Inputs from calbindin-IR primary sensory neurons and from three classes of descending interneurons were studied. Electron-microscopic analysis showed that calbindin-IR axons formed two types of inputs, synapses and close contacts, on calretinin-IR neurons. About 40% of inputs to the longitudinal muscle motor neurons and 70% to ascending interneurons were calbindin-IR. Approximately 50% of longitudinal muscle motor neurons were surrounded by bombesin-IR dense pericellular baskets and 40% by closely apposed varicosities. At the electron-microscope level, the bombesin-IR varicosities were found to form synapses and close contacts with the motor neurons. Dense pericellular baskets with bombesin-IR surrounded 36% of all ascending interneurons, and a further 17% had closely apposed varicosities. Somatostatin- and 5-HT-IR descending interneurons provided no dense pericellular baskets to calretinin-IR nerve cells. Thus, calretinin-IR, longitudinal muscle motor neurons and ascending interneurons receive direct synaptic inputs from intrinsic primary sensory neurons and from non-cholinergic, bombesin-IR, descending interneurons.
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PMID:Sources of inputs to longitudinal muscle motor neurons and ascending interneurons in the guinea-pig small intestine. 760 68

Gangliogliomas, dysembryoplastic neuroepithelial tumors (DNT) and glioneuronal malformations are frequently encountered in patients with pharmacoresistant focal epilepsies. In order to characterize the neurochemical profile of these neoplastic and malformative glioneuronal lesions, we have examined the presence of the alpha 1 subunit of the GABAA receptor, the N-methyl-D-aspartate receptor subunit 1 (NR1), glutamate decarboxylase, tyrosine hydroxylase, somatostatin, parvalbumin, and calretinin in 60 gangliogliomas, 11 DNT, 10 tuberous sclerosis-like lesions and 17 non-tuberous sclerosis-like glioneuronal malformations. All DNT and tuberous sclerosis-like lesions, 59 gangliogliomas (98%), and 13 non-tuberous sclerosis-like hamartias (76%) were positive for at least one of the markers. Despite a great variation between and within the different entities, the neurochemical profile was generally reminiscent of normal neocortex: glutamate decarboxylase, GABAA receptor and NR1 which are common in neocortical neurons were present in the great majority of the lesions and often showed high labeling indices. There were three tuberous sclerosis-like lesions (30%) that contained both NR1 and glutamate decarboxylase immunoreactive giant cells in addition to well-differentiated ganglion cells. This supports the idea that at least some of these giant cells are of neuronal origin. The oligodendroglia-like cells of DNT and glioneuronal hamartias did not show immunoreactivity for any of the markers. The very high incidence of ganglioglial lesions in patients with chronic focal epilepsies and the presence of neurotransmitter-producing enzymes, neurotransmitter receptors, neuropeptides, and calcium-binding proteins in many of these lesions suggests that they may play an active role in the pathogenesis of epileptic seizures.
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PMID:Neurochemical profile of glioneuronal lesions from patients with pharmacoresistant focal epilepsies. 766 58


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