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

It is well established that the mammalian circadian system consists of pacemaker cells in the suprachiasmatic nuclei (SCN). The mouse has become increasingly important in understanding the circadian timing system, due to the availability of mutant animals with abnormal circadian rhythms. In the present paper, we describe the organization of the mouse SCN, comparing the wild type and Clock mutant animal, with a special focus on those peptides bearing an upstream E-box element (vasopressin, vasoactive intestinal peptide, cholecystokinin and substance P). To this end, we describe the distribution of the foregoing SCN peptidergic cell types as well as gastrin-related peptide, calretinin, calbindin, somatostatin, neurotensin and retinal input to the SCN (determined by both tract tracing and fos-immunoreactivity in response to a light pulse). The Clock mutant mouse has decreased expression of vasopressin mRNA and protein in the SCN, with normal patterns of expression elsewhere in the brain. No other differences were detected between the Clock mutant and the wild type mouse. The results are consistent with the hypothesis that there are multiple regulatory elements of clock-controlled genes in the SCN.
...
PMID:Multiple regulatory elements result in regional specificity in circadian rhythms of neuropeptide expression in mouse SCN. 1057 54

Immunocytochemical and autoradiographic methods were used to localize the GABA(B) receptor in the normal rat hippocampus. GABA(B) receptor 1-like immunoreactivity (GBR1-LI) was most intense in presumed GABAergic interneurons of all hippocampal subregions. It was also present throughout the hippocampal neuropil, where it was most intense in the dendritic strata of the dentate gyrus, which are innervated by the perforant pathway and inhibitory dentate hilar cells, and in strata oriens and radiatum of area CA3. The dendritic regions of area CA1 exhibited less GBR1-LI than area CA3. GBR1-LI was detectable in the somata of CA1 pyramidal cells, but was minimal or undetectable within the somata of dentate granule cells and CA3 pyramidal cells. GBR1-LI was similarly minimal in the dentate hilar neuropil, and in stratum lucidum, the two regions that contain granule cell axons and terminals. Nor was GBR1-LI detectable in the inhibitory basket cell fiber systems that surround hippocampal principal cell somata. Fluorescence co-localization studies indicated that significant proportions of interneurons expressing somatostatin, neuropeptide Y, cholecystokinin, calbindin, or calretinin also expressed GBR1-LI constitutively. Conversely, parvalbumin-positive GABAergic basket cells of the dentate gyrus and hippocampus, which form GABA(A) receptor-mediated inhibitory axo-somatic synapses, rarely contained detectable GBR1-LI. High resolution autoradiography with the GABA(B) receptor antagonist CGP 62349 revealed a close correspondence between receptor ligand binding and GBR1-LI, with several notable exceptions. Ligand binding closely matched GBR1-LI throughout the hippocampal, cortical, thalamic, and cerebellar neuropil. However, the hippocampal interneuron somata and dendrites that exhibited the most intense GBR1-LI, and the GBR1-positive somata of CA1 pyramidal cells, did not exhibit a similar density of [3H]-CGP 62349 binding. These data clarify the relationship between immunocytochemically identified receptor protein and potentially functional receptors, indicating that GBR1-LI reflects both non-functional cytoplasmic GBR1 and the ligand-bindable form of the protein, both before dimerization with GBR2 and after translocation to functional sites within cells. The staining and binding patterns further suggest that GBR1 is constitutively expressed in specific neuronal populations, and may exist in higher concentration in the axons of inhibitory hippocampal pathways that innervate dendritic zones, than in axo-somatic inhibitory terminals. Whether GBR1 is inducible in cells that contain GBR1 mRNA, but no detectable constitutive protein, remains to be determined in experimental studies.
...
PMID:Localization of GABA(B) (R1) receptors in the rat hippocampus by immunocytochemistry and high resolution autoradiography, with specific reference to its localization in identified hippocampal interneuron subpopulations. 1058 87

By coupling glutamate to the IP(3) signaling pathway, group I metabotropic receptors can increase intracellular Ca(2+) concentration, and might thus contribute to excitotoxicity. To identify neurons that might be vulnerable to such injury, we performed immunofluorescence histochemistry for metabotropic glutamate receptor 1alpha (mGluR1alpha) in the cerebral cortex of adult rat. mGluR1alpha was in somata and dendrites of a subset of non-pyramidal neurons scattered throughout the cerebral cortex. To further characterize mGluR1alpha-positive neurons, we investigated its colocalization with several neurochemical markers. Nearly all mGluR1alpha-positive cells were interneurons immunopositive for gamma-aminobutyric acid. The majority (70-80%) of mGluR1alpha-immunopositive neurons were double-labeled for somatostatin. Approximately half of calretinin-positive neurons and 30% of calbindin-positive neurons expressed mGluR1alpha. In contrast, parvalbumin-expressing neurons were rarely positive for mGluR1alpha. Neurons staining strongly for mGluR1alpha were also positive for GluR1. These results indicated that mGluR1alpha is expressed by specific classes of GABAergic neurons in the neocortex, and suggests a mechanism by which these neurons may be especially vulnerable to excitotoxic injury.
...
PMID:Immunolocalization of mGluR1alpha in specific populations of local circuit neurons in the cerebral cortex. 1075 63

The functional role of the calcium-binding proteins parvalbumin, calretinin, and calbindin D-28k for epileptogenesis and long-term seizure-related alterations of the hippocampal formation was assessed in single- and double-knockout mice, using a kainate model of mesial temporal lobe epilepsy. The effects of a unilateral intrahippocampal injection of kainic acid were assessed at one day, 30 days, and four months post-injection, using various markers of GABAergic interneurons (GABA-transporter type 1, GABA(A)-receptor alpha1 subunit, calretinin, calbindin D-28k, somatostatin, and neuropeptide Y). Parvalbumin-deficient, parvalbumin/calbindin-deficient, and parvalbumin/calretinin-deficient mice exhibited no difference in cytoarchitecture of the hippocampal formation and in the number, distribution, or morphology of interneurons compared to wild-type mice. Likewise, mutant mice were not more vulnerable to acute kainate-induced excitotoxicity or to long-term effects of recurrent focal seizures, and exhibited the same pattern of neurochemical alterations (e.g., bilateral induction of neuropeptide Y in granule cells) and morphogenic changes (enlargement and dispersion of dentate gyrus granule cells) as wild-type animals. Quantification of interneurons revealed no significant difference in neuronal vulnerability among the genotypes.These results indicate that the calcium-binding proteins investigated here are not essential for determining the neurochemical phenotype of interneurons. Furthermore, they are not protective against kainate-induced excitotoxicity in this model, and do not appear to modulate the overall level of excitability of the hippocampus. Finally, seizure-induced changes in gene expression in granule cells, which normally express high levels of calcium-binding proteins, apparently were not affected by the gene deletions analysed.
...
PMID:Neurodegenerative and morphogenic changes in a mouse model of temporal lobe epilepsy do not depend on the expression of the calcium-binding proteins parvalbumin, calbindin, or calretinin. 1077 38

A classification of fusiform neocortical interneurons (n = 60) was performed with an unsupervised cluster analysis based on the comparison of multiple electrophysiological and molecular parameters studied by patch-clamp and single-cell multiplex reverse transcription-PCR in rat neocortical acute slices. The multiplex reverse transcription-PCR protocol was designed to detect simultaneously the expression of GAD65, GAD67, calbindin, parvalbumin, calretinin, neuropeptide Y, vasoactive intestinal peptide (VIP), somatostatin (SS), cholecystokinin, alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid, kainate, N-methyl-d-aspartate, and metabotropic glutamate receptor subtypes. Three groups of fusiform interneurons with distinctive features were disclosed by the cluster analysis. The first type of fusiform neuron (n = 12), termed regular spiking nonpyramidal (RSNP)-SS cluster, was characterized by a firing pattern of RSNP cells and by a high occurrence of SS. The second type of fusiform neuron (n = 32), termed RSNP-VIP cluster, predominantly expressed VIP and also showed firing properties of RSNP neurons with accommodation profiles different from those of RSNP-SS cells. Finally, the last type of fusiform neuron (n = 16) contained a majority of irregular spiking-VIPergic neurons. In addition, the analysis of glutamate receptors revealed cell-type-specific expression profiles. This study shows that combinations of multiple independent criteria define distinct neocortical populations of interneurons potentially involved in specific functions.
...
PMID:Classification of fusiform neocortical interneurons based on unsupervised clustering. 1082 57

mu-Opioid receptor-expressing neurons in the rat cerebral neocortex were characterized by an immunolabeling method with an antibody to a carboxyl terminal portion of the receptor. They were small, bipolar, vertically elongated, non-pyramidal neurons, and scattered mainly in layers II-IV. We examined chemical characteristics of mu-opioid receptor-expressing neocortical neurons by the double immunofluorescence method. Almost all neuronal cell bodies expressing mu-opioid receptor-like immunoreactivity showed immunoreactivity for GABA, suggesting that they were cortical inhibitory interneurons. mu-Opioid receptor-immunoreactive neurons were further studied by the double staining method with markers for the subgroups of cortical GABAergic neurons. Immunoreactivities for vasoactive intestinal polypeptide, corticotropin releasing factor, choline acetyltransferase, calretinin and cholecystokinin were found in 92, 79, 67, 35 and 35% of mu-opioid receptor-immunoreactive cortical neurons, respectively. In contrast, less than 10% of mu-opioid receptor-immunoreactive neurons showed immunoreactivity for parvalbumin, calbindin, somatostatin, neuropeptide Y or nitric oxide synthase. Moreover, mu-opioid receptor-immunoreactive neurons very frequently exhibited preproenkephalin immunoreactivity, but not preprodynorphin immunoreactivity. The present results indicate that mu-opioid receptor-expressing neurons belong to a distinct subgroup of neocortical GABAergic neurons, because vasoactive intestinal polypeptide, corticotropin releasing factor, choline acetyltransferase, calretinin and cholecystokinin have often been reported to coexist with one another in single neocortical neurons. Methionine-enkephalin, which is a major product of the preproenkephalin gene, is known to be one of the most potent endogenous ligands for mu-opioid receptor. Thus, the expression of mu-opioid receptor in preproenkephalin-producing neurons suggested that mu-opioid receptor serves as an autoreceptor for the subpopulation of GABAergic interneurons at a single-neuron or population level.
...
PMID:A group of cortical interneurons expressing mu-opioid receptor-like immunoreactivity: a double immunofluorescence study in the rat cerebral cortex. 1085 53

In a previous study, we described a population of striatal cells in the rat brain containing aromatic L-amino acid decarboxylase, the enzyme involved in the conversion of L-DOPA into dopamine. We have also presented evidence that these cells produce dopamine in the presence of exogenous L-DOPA. In this paper, we further characterize these striatal aromatic L-amino acid decarboxylase-containing cells in order to determine whether they form a subclass of one of the known categories of striatal neurons or if they represent a novel cell type. Using immunohistochemical methods, we compared the morphology and distribution of the aromatic L-amino acid decarboxylase-immunolabeled cells with those of other classes of striatal neurons. Our results show that both the morphology and distribution of aromatic L-amino acid decarboxylase-immunolabeled cells are very distinctive and do not resemble those of cells labeled for other striatal neuronal markers. Double-labeling procedures revealed that aromatic L-amino acid decarboxylase cells do not co-localize somatostatin or parvalbumin, and only a very small percentage of them co-localize calretinin. However, the population of aromatic L-amino acid decarboxylase cells label intensely for GABA.Overall, our results suggest that these aromatic L-amino acid decarboxylase-containing cells represent a class of striatal GABAergic neurons not described previously.
...
PMID:Striatal cells containing aromatic L-amino acid decarboxylase: an immunohistochemical comparison with other classes of striatal neurons. 1086 44

Alpha-actinin (alpha-actinin-2) is a protein which links the NR1 and NR2B subunits of N-methyl-D-aspartate (NMDA) glutamate receptors to the actin cytoskeleton. Because of the importance of NMDA receptors in modulating the function of the striatum, we have examined the localization of alpha-actinin-2 protein and mRNA in striatal neurons, and its biochemical interaction with NMDA receptor subunits present in the rat striatum. Using an alpha-actinin-2-specific antibody, we found intense immunoreactivity in the striatal neuropil and within striatal neurons that also expressed parvalbumin, calretinin and calbindin. Conversely, alpha-actinin-2 immunoreactivity was not detected in neurons expressing choline acetyltransferase and neuronal nitric oxide synthase. Dual-label in situ hybridization revealed that the highest expression of alpha-actinin-2 mRNA is in substance P-containing striatal projection neurons. The alpha-actinin-2 mRNA is also present in enkephalinergic projection neurons and interneurons expressing parvalbumin, choline acetyl transferase and the 67-kDa isoform of glutamic acid decarboxylase, but was not detected in somatostatin-expressing interneurons. Immunoprecipitation of membrane protein extracts showed that alpha-actinin-2 is present in heteromeric complexes of NMDA subunits, but is not associated with AMPA receptors in the striatum. A subunit-specific anti-NR1 antibody co-precipitated major fractions of NR2A and NR2B subunits, but only a minor fraction of striatal alpha-actinin-2. Conversely, alpha-actinin-2 antibody immunoprecipitated only modest fractions of striatal NR1, NR2A and NR2B subunits. These data demonstrate that alpha-actinin-2 is a very abundant striatal protein, but exhibits cellular specificity in its expression, with very high levels in substance-P-containing projection neurons, and very low levels in somatostatin and neuronal nitric oxide synthase interneurons. Despite the high expression of this protein in the striatum, only a minority of NMDA receptors are linked to alpha-actinin-2. This interaction may identify a subset of receptors with distinct anatomical and functional properties.
...
PMID:alpha-actinin-2 in rat striatum: localization and interaction with NMDA glutamate receptor subunits. 1092 45

The striatum, the largest component of the basal ganglia, contains projection neurons and interneurons. Whereas there is considerable agreement that the lateral ganglionic eminence (LGE) is the origin of striatal projection neurons, less is known about the origin of striatal interneurons. Using focal injections of retrovirus into the ventral telencephalon in vitro, we demonstrate that most striatal interneurons tangentially migrate from the medial ganglionic eminence (MGE) or the adjacent preoptic/anterior entopeduncular areas (POa/AEP) and express the NKX2.1 homeodomain protein. Although the majority of striatal interneurons (cholinergic, calretinin(+), and parvalbumin(+)) maintain the expression of NKX2.1 into adulthood, most of the interneurons expressing somatostatin (SOM), neuropeptide Y (NPY), and neural nitric oxide synthase (NOS) appear to downregulate the expression of NKX2.1 as they exit the neuroepithelium. Analysis of striatal development in mice lacking Nkx2.1 suggests that this gene is required for the specification of nearly all striatal interneurons. Similar analysis of mice lacking the Mash1 basic helix-loop-helix (bHLH) or both the Dlx1 and Dlx2 homeodomain transcription factors demonstrates that these genes are required for the differentiation of striatal interneurons. Mash1 mutants primarily have a reduction in early-born striatal interneurons, whereas Dlx1/2 mutants primarily have reduced numbers of late-born striatal interneurons. We also present evidence implicating the Lhx6 and Lhx7 LIM-homeobox genes in the development of distinct interneuron subtypes. Finally, we hypothesize that, within the MGE, radially migrating cells generally become projection neurons, whereas tangentially migrating cells mainly form interneurons of the striatum and cerebral cortex.
...
PMID:Origin and molecular specification of striatal interneurons. 1093 56

The histochemistry of reduced nicotinamide adenine dinucleotide phosphate diaphorase (NADPH-d) and immunoreactivity of neuronal nitric oxide synthase (nNOS-IR) can be demonstrated in various cell types of the vertebrate retina. In this study, we have focused on characterizing the different NADPH-d-positive amacrine cell types in turtle retina. Cryostat sections were examined by confocal laser scanning microscopy for double immunofluorescence with antibodies against nNOS and either GABA or glycine, or by combining histochemistry with immunocytochemistry to obtain triple labeling with NADPH-d, GABA, and glycine. Forty-eight percent of the NADPH-d-labeled amacrine cells colocalized GABA, 52% glycine. Here we show that two morphologically different types of amacrine cell are nNOS/glycine-IR and three types are nNOS/GABA-IR. Antibodies against calretinin, parvalbumin, somatostatin, tyrosine hydroxylase, and choline acetyltransferase did not colocalize with nNOS-IR or NADPH-d-labeled amacrine cells, but 15% of the NOS-labeled amacrine cells showed immunoreactivity against calbindin. Only GABA has been seen to colocalize with NADPH-d in amacrine cells in previous reports in other species. The finding here of glycine colocalizing with NO-containing cells is novel. We suggest that NO, apart from its well known function in gap junction regulation, can also modulate the release of both GABA and glycine in the turtle retina.
...
PMID:Morphological and neurochemical diversity of neuronal nitric oxide synthase-positive amacrine cells in the turtle retina. 1107 11


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>