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)

Tissue concentrations of the neuropeptide somatostatin and the specific activities of glutamic acid decarboxylase (GAD) were measured in several regions of the central nervous system in young rats, following chronic postnatal administration of methylmercuric chloride. By the beginning of the fourth postnatal week, these animals exhibited clinical signs of a mixed spastic/dyskinetic syndrome with visual deficits. At the onset of neurological impairment, a significant decrease in GAD activity was detected in the occipital cortex (48-49%) and striatum (45-50%) when compared to either normal or weight-matched controls. At one subclinical stage of toxicity, decreased GAD activity was detected only in the occipital cortex (29-30%). Tissue levels of somatostatin did not change significantly in the occipital cortex of methylmercury-treated animals at any stage of the experiment. However, somatostatin levels in the striatum were significantly reduced at the onset of neurological impairment (55-57%) and at one subclinical stage of toxicity (49-54%). Immunohistochemistry for somatostatin- and neuropeptide Y-immunoreactive neurons confirmed a marked loss of cells in the dorsolateral region of the striatum with atrophy of the surviving neurons. In the cerebral cortex of methylmercury-treated animals the morphology and distribution of somatostatin-positive neurons appeared normal. In view of the reported co-localization of GAD and somatostatin in some non-pyramidal neurons of the cerebral cortex, these results indicate that methylmercury-induced lesions of the developing cerebral cortex involve a subpopulation of GABAergic neurons which are not co-localized with somatostatin. In the striatum, where GAD and somatostatin are not co-localized within the same neurons, methylmercury-induced lesions involve both GABAergic and somatostatin-positive neurons.
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PMID:Methylmercury-induced movement and postural disorders in developing rat: loss of somatostatin-immunoreactive interneurons in the striatum. 289 69

The laterodorsal tegmental nucleus (ntdl) contains a cluster of cells located just medial to the locus coeruleus in the pontine brainstem. The ntdl has been shown to project both rostrally to the forebrain and diencephalon and caudally to the spinal cord. In an effort to characterize this region neurochemically, the present study was conducted to identify a variety of neurochemicals localized within perikarya and fibers of the ntdl and surrounding nuclei. Rats were perfused with formalin, and brain sections were processed for fluorescence immunocytochemistry and acetylcholinesterase (AChE). Of the neurochemicals screened, atrial natriuretic factor (ANF), choline acetyltransferase (ChAT), cholecystokinin (CCK), calcitonin gene-related peptide (CGRP), dynorphin B (Dyn B), galanin, somatostatin, substance P, neurotensin (NT), neuropeptide Y (NPY), vasopressin, vasoactive intestinal polypeptide (VIP), serotonin (5HT), glutamic acid decarboxylase (GAD), and tyrosine hydroxylase (TH) were studied. AChE and ChAT staining revealed that the ntdl contains mostly cholinergic neurons. In addition, brightly reactive substance P and galanin and paler staining CRF, ANF, CGRP, NT, VIP, and Dyn B cell bodies were found within the ntdl. Varicose fibers in this nucleus also contained these peptides in addition to CCK, GAD, TH, 5HT, and NPY. The dorsal tegmental nucleus, dorsal raphe nucleus, locus coeruleus, and the parabrachial region contained a dense and varied assortment of peptides with distinct positions and patterns. This multiplicity of neurochemicals within this area suggests a possible influence on a variety of functions modulated by the ntdl and other closely associated tegmental nuclei.
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PMID:Immunocytochemical localization of peptides and other neurochemicals in the rat laterodorsal tegmental nucleus and adjacent area. 289 81

Experiments utilizing a combination of [3H]thymidine autoradiography and immunohistochemistry were conducted to determine the time of origin of somatostatin-immunoreactive (SSIR) neurons in the hippocampal formation of the rat. A quantitative and topographic description of neurogenesis in this peptide-containing neuronal system was generated using a computer-aided system to plot the position of labeled cells. Dissected and 'flattened' hippocampal preparations were used to facilitate the analysis of spatial gradients of SSIR cell development. The results indicate that most SSIR hippocampal cells are generated during a short embryonic period which extends from the 12th through the 15th day of gestation (E12-E15). Within this period of development, the distribution of SSIR cells follows a spatial gradient along the transverse or subiculo-dentate axis of the hippocampus. The earliest formed SSIR neurons, generated on E12 and E13, are preferentially distributed to the subiculum, those generated on E14 are most commonly observed throughout the CA1-CA3 fields of the hippocampus and SSIR neurons which become postmitotic on E15 are more heavily represented in the hilar region of the dentate gyrus than cells born at other stages of development. There was no clear-cut neurogenic gradient along the septotemporal axis of the hippocampus. These results indicate that somatostatin cells in the rat hippocampal formation are generated during the same prenatal period when glutamic acid decarboxylase (GAD)-positive neurons become postmitotic. These studies also suggest that quantitative developmental analyses of chemically specific cell types can reveal prominent features of cortical ontogeny that are not readily apparent in standard [3H]thymidine preparations.
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PMID:The time of origin of somatostatin-immunoreactive neurons in the rat hippocampal formation. 290 62

Fetal parietal cerebral cortex was transplanted to the anterior eye chamber of adult Sprague-Dawley rats. After two to three months the grafts, with or without colchicine treatment, were subjected to immunohistochemical analysis using antibodies against cholecystokinin (CCK), somatostatin (SOM), neuropeptide tyrosine (NPY), vasoactive intestinal polypeptide (VIP), peptide histidine isoleucine (PHI) and the GABA-synthesizing enzyme glutamic acid decarboxylase (GAD). Cerebral cortex in situ of untreated and colchicine-treated rats was always analyzed in parallel. A dense plexus of CCK-immunoreactive fibers was distributed in all parts of the transplants, and after colchicine treatment a large number of CCK-positive cells was observed. These cells were markedly increased in number as compared to normal cortical tissue in colchicine-pretreated rats. The amount of NPY-immunoreactive cells was also markedly increased, whereas somatostatin-positive cells were found in numbers similar to those seen in cortex in situ. In the grafts only a few VIP- and PHI-positive fibers were seen with a few VIP-positive cell bodies, but no clearly discernible PHI-positive cells. A very dense plexus of GAD-positive fibers with an even distribution throughout the grafts was observed. Cortex in situ exhibited a lower density of GAD-immunoreactive fibers. Even after colchicine treatment the number of GAD-positive cells in the grafts was low. Using double-staining techniques, it was found that most of the few GAD-positive cells in the grafts were also NPY-positive, SOM-positive or, to a minor extent, CCK-positive. The present results demonstrate that several peptides and transmitter markers are expressed in cortical grafts in oculo, but marked differences in their expression can be observed in cortical tissue that has developed in isolation. Thus, the intraocular cortex graft, alone and in combination with other brain areas, should provide a useful model in which to study factors that regulate brain development.
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PMID:Glutamic acid decarboxylase- and peptide-immunoreactive neurons in cortex cerebri following development in isolation: evidence of homotypic and disturbed patterns in intraocular grafts. 290 91

Immunocytochemical techniques have been used to identify a striking interneuronal population which is immunoreactive for the peptide, somatostatin. The cell population, which is seen most densely in stratum oriens and at the oriens/alveus border of the CA1 region of rabbit hippocampus, was characterized in light and electron microscopic observations. The cells have dendrites which extend parallel to and into the alveus, with occasional processes ascending through stratum pyramidale toward the hippocampal fissure. The dendrites receive numerous synaptic contacts directly onto aspinous dendritic shafts. Axon collaterals ramify profusely within the pyramidale region, and among the proximal apical and basal pyramidal cell dendrites in areas of stratum radiatum and stratum oriens. Somatostatin-like immunoreactive terminals make synaptic contact, primarily of the symmetric type, with the somata and proximal dendrites of pyramidal neurons. Somatostatin-like neurons are found at approximately equal density in the hippocampus of immature (8 days postnatal) and mature (30 days postnatal) rabbit. Double-labelling techniques, to identify both somatostatin-like and glutamic acid decarboxylase (GAD) immunoreactive neurons, demonstrated that a large proportion of the somatostatin neurons were also GABAergic.
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PMID:Ultrastructural characterization and GAD co-localization of somatostatin-like immunoreactive neurons in CA1 of rabbit hippocampus. 290 65

Indirect immunofluorescence histochemistry was used to study the relation among GABAergic, catecholaminergic, cholinergic, and peptidergic neurons in the rat mediobasal hypothalamus. By employing a direct double-labelling procedure using sheep antiserum against glutamic acid decarboxylase (GAD), mouse monoclonal and rabbit antibodies to neurotensin (NT) and rabbit antisera to tyrosine hydroxylase (TH), choline acetyltransferase (ChAT), galanin (GAL), growth hormone-releasing factor (GRF), or somatostatin (SOM), it was demonstrated that GAD-positive fibers and terminals in the external part of the median eminence co-contained immunoreactivity for TH, NT, GAL or GRF, but not for SOM. In the internal part of the median eminence-infundibular stalk, GAD-positive/NT-, GAL-, and GRF-negative and GAD-positive/TH-positive fiber plexa were shown. When a recently developed direct triple-labelling procedure with biotin-conjugated mouse secondary antibodies in conjunction with diethylaminocoumarin (DAMC)-conjugated avidin was employed, presence of GAD/GAL/NT- as well as GAD/GRF/NT-containing varicosities could be demonstrated close to hypophysial portal vessels. In colchicine-pretreated animals, GAD was shown to coexist with TH, NT, or GAL in cell bodies in both the dorsomedial and ventrolateral domains of the arcuate nucleus, but with GRF only in the ventrolateral division. ChAT-positive neurons in the ventrolateral region were also TH-positive. In the ventrolateral arcuate nucleus, triple-labelling followed by elution-restaining showed GAD/NT/GAL/TH-immunoreactivities in the same cells. Similarly, double-labelling with two following elution-restaining steps showed several NT/GAL/GRF/TH-containing cell bodies in this part of the arcuate nucleus. GAD-positive cells in the anterior hypothalamic periventricular area and fibers in the pituitary neurointermediate lobe were also TH-positive. The results demonstrate complex patterns of storage of chemical messengers in neurons of the arcuate nucleus-median eminence complex. Possible neuroendocrine interactions of these systems in the control of prolactin and growth hormone secretion are discussed.
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PMID:Peptide- and transmitter-containing neurons in the mediobasal hypothalamus and their relation to GABAergic systems: possible roles in control of prolactin and growth hormone secretion. 290 36

Borna disease (BD) agent is an infectious pathogen that causes progressive central nervous system (CNS) dysfunction in a wide range of vertebrate hosts. The course of BD in adult rats is biphasic. The acute phase is characterized by aggressive behavior and inflammatory cell infiltrates in brain. With chronic infection animals become listless and inflammation resolves. BD antigens are similarly distributed in neurons in hippocampus, neocortex, cerebellum and brainstem in acutely and chronically infected animals. We have recently examined brain levels of neuronal transcripts in rats with acute and chronic BD. Levels for 3 of these mRNAs, cholecystokinin, glutamic acid decarboxylase and somatostatin, were decreased in acutely infected rats and increased toward control values in chronically infected rats. A fourth transcript, MuBr8, correlated in distribution with BD antigen, was persistently decreased throughout the course of infection. These data may have implications for understanding the pathogenesis of neurologic disturbances in BD and other inflammatory CNS diseases.
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PMID:Neurotransmitter abnormalities in Borna disease. 290 25

The distribution of somatostatin-like immunoreactive (SS-LI) material and its colocalization with glutamic acid decarboxylase (GAD)-like immunoreactivity were studied in the rat hippocampus and dentate gyrus neurons using immunohistochemistry. In the dentate gyrus and CA1 region, SS-LI perikarya were concentrated in the hilus and in the stratum oriens, respectively, whereas immunoreactive cell bodies were rarely seen in other layers. Approximately half of the SS-LI neurons of the CA3 region were situated in the stratum oriens, the other half being scattered in strata pyramidale, lucidum and radiatum. About 90% of SS-LI neurons were also GAD-like immunoreactive, whereas about 14% of GAD-like immunoreactive (GAD-LI) neurons were SS-like immunoreactive. The percentage of GAD-LI neurons which were also immunoreactive for SS varied from one layer to the other. This percentage was about 30% in the hilus of the dentate gyrus and in the stratum oriens of the CA1 and CA3 regions; it was 5-10% in the strata pyramidale, lucidum and radiatum of the CA3 region and reached only 2% in the granule cell layer and molecular layer of the dentate gyrus and in the stratum pyramidale and stratum radiatum in the CA1 region. These observations indicate that the majority of SS-LI neurons in the rat hippocampal formation are a subpopulation of GABAergic neurons.
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PMID:GABAergic neurons containing somatostatin-like immunoreactivity in the rat hippocampus and dentate gyrus. 316 71

The GABAergic properties of dissociated neurons from cerebral cortex of neonatal rats were studied in primary culture using electrophysiological, biochemical and immunohistochemical methods. Cultured neurons had a resting potential of -50 to -60 mV and exhibited spontaneous excitatory and inhibitory synaptic currents. Non-spontaneous (elicited) ionic currents were produced by direct application of GABA and glutamate. Cultures contained measurable amounts of GABA from the first day in culture; GABA content reached a plateau around the 10th day of culture, and continued, nearly unchanged, until the 21st day of culture. Immunohistochemistry showed that 45% of the total cells in culture contained glutamic acid decarboxylase (GAD). Octadecaneuropeptide (ODN), a putative neuroregulatory peptide for benzodiazepine recognition sites, was present in approximately 28% of all neurons. Ninety-three percent of ODN-positive cells demonstrated GABAergic properties as well by displaying GAD-immunoreactivity. The peptide GABA-modulin (GM), a putative GABA receptor modulator, was found in about 75% of all neurons, with a further 65% of these cells exhibiting GAD-immunoreactivity. Cells immunopositive for neuropeptide Y (NPY), somatostatin (SRIF), and cholecystokinin-octapeptide (CCK), were found at much lower incidence (1-4%). Double-labelling studies showed that 90-97% of the cells positive for NPY, SRIF and CCK were also positive for GAD. Cells immunoreactive with serotonin or tyrosine hydroxylase were not detected. We suggest that primary cultures of neonatal cortical neurons may provide a useful experimental model to investigate the function and the modulation of GABAergic neurotransmission in the cerebral cortex.
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PMID:Subsets of GABAergic neurons in dissociated cell cultures of neonatal rat cerebral cortex show co-localization with specific modulator peptides. 337 69

The distribution of retinohypothalamic projections and the organization of the suprachiasmatic region of the hypothalamus was investigated in the house sparrow (Passer domesticus). Retinohypothalamic projections (RHT) were studied by two anterograde tracing methods, and hypothalamic organization was investigated immunohistochemically with antisera against a number of substances known to be present in the mammalian suprachiasmatic nucleus (SCN): bombesin (BBS), glutamic acid decarboxylase (GAD), 5-hydroxytryptamine (5HT), neuropeptide Y (NPY), neurotensin (NT), somatostatin (SS), substance P (SP), vasoactive intestinal polypeptide (VIP), and arginine vasopressin (AVP). Observations from these experiments were analysed within the framework of a cytoarchitectural study using Nissl-stained material. From this study, we have identified an area in the anterior hypothalamus which we believe is an avian homologue of the mammalian SCN. This area contains a nucleus located in close apposition to the optic chiasm between the dorsal supraoptic decussation (DSD) and the ventral lateral geniculate body (GLv) for much of its rostrocaudal extent. The central portion of this nucleus contains neurons that exhibit GAD- and BBS-like immunoreactivity and is the terminal field for the RHT. For this reason, we term this nucleus the visual SCN. It also contains axon plexuses exhibiting 5HT-like, SP-like, and NPY-like immunoreactivity and is bordered ventrally by AVP-like, SP-like, and NT-like immunoreactive cells and medially by VIP-like and SS-like immunoreactive cells. Although it is not established that these cell groups together compose a single suprachiasmatic nucleus, the organization in the avian brain of a nuclear complex with a retinorecipient area surrounded by nonvisual components would be very similar to that of the mammalian SCN.
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PMID:Retinohypothalamic projection and suprachiasmatic nucleus of the house sparrow, Passer domesticus. 343 73


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