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)

The ontogeny of somatostatin receptors in the rat visual system was studied by auto-radiography, using [125I-Tyr0,DTrp8]S14 as a radioligand. The binding sites showed high affinity for somatostatin and somatostatin analogues, and were regulated by GTP as early as day 16 of fetal life (E16), indicating that they represent functional somatostatin receptors. The density of somatostatin receptors was quantified by computerized image-analysis of film autoradiograms, and by grain counting on emulsion-coated slides. During fetal life, somatostatin receptors were observed in the retina, optic nerve, optic chiasma, optic tract, and lateral geniculate nucleus. The highest densities of somatostatin receptors were measured from E16 to E18 in the retina and primary optic pathways. During the first postnatal days, the density of somatostatin receptors decreased dramatically in the retina. In both the optic pathways and dorsal lateral geniculate nucleus, somatostatin receptors gradually disappeared, and the levels of somatostatin receptors were almost undetectable at postnatal day 21 (P21). Conversely, the density of somatostatin receptors remained stable in the ventral lateral geniculate nucleus during the early postnatal life (P0-P7). The timing of expression and the localization of somatostatin receptors in the developing visual system suggest that the immature ganglion cells are responsible for the expression of these evanescent somatostatin receptors. After eye opening, the distribution patterns of somatostatin receptors in the retina and the lateral geniculate nucleus were similar to those observed in adults. In particular, from P14 onwards, somatostatin receptors were concentrated in the inner plexiform layer and, to a lesser extent, in the ganglion cell and photoreceptor layers. In the ventral lateral geniculate nucleus, a heterogeneous distribution of somatostatin receptors was noted, the highest densities being found in the intergeniculate leaflet and the medial zone limiting the parvo-magnocellular interface. The distribution of somatostatin receptors in the retina and the ventral lateral geniculate nucleus after the second postnatal week, together with the presence of somatostatin-like immunoreactive elements in these structures, provide support for the involvement of somatostatin as a neurotransmitter or neuromodulator in the visual system of the adult rat. Conversely, the transient expression of somatostatin receptors observed before maturation and complete organization of the optic pathways suggests that somatostatin plays a trophic role during development of the visual system.
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PMID:Transient expression of somatostatin receptors in the rat visual system during development. 167 5

A number of neuroactive peptides including calcitonin gene-related peptide (CGRP), substance P, neurokinin B, opioids, somatostatin (SRIF), galanin, neurotensin and vasoactive intestinal polypeptide (VIP) have been localized in adult rat spinal cord and are considered to participate either directly and/or indirectly in the processing of sensory, motor and autonomic functions. Most of these peptides appear early during development, leading to the suggestion that peptides, in addition to their neurotransmitter/neuromodulator roles, may possibly be involved in the normal growth and maturation of the spinal cord. To provide an anatomical substrate for a better understanding of the possible roles of peptides in the ontogenic development of the cord, we investigated the topographical profile as well as variation in densities of [125I]hCGRP alpha, [125I]substance P/neurokinin-1 (NK-1), [125I]eledoisin/neurokinin-3 (NK-3), [125I]FK 33-824 ([D-Ala2, Me-Phe4, Met(O)ol5]enkephalin)/mu-opioid, [125I]galanin, [125I]T0D8-SRIF14 (an analog of somatostatin); [125I]neurotensin and [125I]VIP binding sites in postnatal and adult rat spinal cord using in vitro quantitative receptor autoradiography. Receptor binding sites recognized by each radioligand are found to be distributed widely during early stages of postnatal development and then to undergo selective modification to attain their adult profile of distribution during the third week of postnatal development. The apparent density of various receptor sites, however, are differently regulated depending on the lamina and the stage of development studied. For example, the density of mu-opioid binding sites, following a peak at postnatal day 4 (P4), declines gradually in almost all regions of the spinal cord with the increasing age of the animal. [125I]substance P/NK-1 binding sites, on the other hand, show very little variation until P14 and then subsequently decrease as the development proceeds. In the adult rat, most of these peptide receptor binding sites are localized in relatively high amounts in the superficial laminae of the dorsal horn. To varying extents, moderate to low density of various peptide receptor binding sites are also found to be present in the ventral horn, intermediolateral cell column and around the central canal. Taken together, these results suggest that each receptor-ligand system is regulated differently during development and may each uniquely be involved in cellular growth, differentiation and in maturation of the normal neural circuits of the spinal cord. Furthermore, the selective localization of various receptor binding sites in adult rat spinal cord over a wide variety of functionally distinct regions reinforces the neurotransmitter/modulator roles of these peptides in sensory, motor and autonomic functions associated with the spinal cord.
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PMID:Neuropeptide receptors in developing and adult rat spinal cord: an in vitro quantitative autoradiography study of calcitonin gene-related peptide, neurokinins, mu-opioid, galanin, somatostatin, neurotensin and vasoactive intestinal polypeptide receptors. 778 2

The development of somatostatin immunoreactive (SOM-ir) neurons in cat striate and extrastriate cortex was studied to determine whether temporal changes in the morphology, distribution and density of SOM-ir neurons during development would provide clues to the emergence of specific cortical areas. The visual cortical areas examined included areas 17-19 and 7, posteromedial lateral suprasylvian, posterolateral lateral suprasylvian cortex and splenial visual area. We observed that the pattern of SOM-ir neurons in the cortical plate reflects the maturation of the cortical plate. At 1 week of age, SOM-ir neurons were only found in layers V and VI of the developing cortex; by 2 weeks of age, SOM-ir neurons were found in layer IV; and by 3 weeks of age, SOM-ir neurons were located in all layers of the cortex except layer I. SOM-ir neurons in the subplate were much more numerous under lateral cortical areas than under medial areas. This difference decreased over the first 2 postnatal weeks and by the 14th day after birth (P14), the distribution and numbers of SOM-ir neurons in the subplate/white matter had reached the adult pattern. The timing of exuberant SOM expression in the subplate suggests a function in the formation of visual corticocortical connections which begin to develop during the first postnatal week in the kitten.
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PMID:The development of somatostatin immunoreactive neurons in cat visual cortical areas. 809 74

The expression of the voltage-gated K(+)-channel subunit Kv3.1b in the developing hippocampus was determined by immunoblot and immunohistochemical techniques. Kv3.1b protein was detected first at postnatal day (P) 8. The Kv3.1b-immunopositive cell number per tissue section reached a maximum at P14 and was maintained through P40. In contrast, the Kv3.1b protein content of isolated membrane vesicles in immunoblots progressively increased through P40, suggesting an increase in Kv3.1b content per cell throughout this time period. Kv3.1b protein was expressed selectively in the somata, proximal dendrites, and axons of cells lying within or near the pyramidal cell layer, consistent with their being GABAergic inhibitory interneurons. Kv3.1b was present in approximately 80% of parvalbumin-positive interneurons. The developmental onset of Kv3.1b and parvalbumin immunoreactivity was identical. In contrast, Kv3.1b was mostly absent from the subset of somatostatin-positive inhibitory interneurons. Electrophysiological recordings were made from stratum pyramidale interneurons in which morphology and Kv3.1b-positive immunoreactivity were confirmed post hoc. Outward currents had voltage-dependent and biophysical properties resembling those of channels formed by Kv3.1b. The current blocked by low concentrations of 4-aminopyridine (4-AP) showed marked inactivation, suggesting that Kv3.1b may coassemble with other members of the Kv3 subfamily. In current-clamp recordings, concentrations of 4-AP that blocked the current through Kv3.1b channels allowed us tentatively to assign a role to Kv3.1b-containing channels in action-potential repolarization. These data demonstrate that Kv3.1b is regulated developmentally in a specific subpopulation of hippocampal interneurons and that channels containing this subunit may be a major determinant in imparting "fast-spiking" characteristics to these and other cells throughout the central nervous system containing the Kv3.1b subunit.
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PMID:Developmental expression and functional characterization of the potassium-channel subunit Kv3.1b in parvalbumin-containing interneurons of the rat hippocampus. 855 35

We have previously shown that dark rearing moderates the normal decline in the number of somatostatin (SRIF) and neuropeptide (NPY) neurons in the developing rat visual cortex. Thus, cortical areas of visually deprived animals at postnatal day (P) 60 contain consistently more SRIF and NPY neurons than do the same areas of rats reared in normal lighting conditions. In present study animals were reared in darkness from birth to P14, P21, P30 or P60 and then placed in ambient light conditions up to the day of sacrifice (P60 or P90). Counting of immunocytochemically identified SRIF and NPY neurons in all cortical visual areas of these and of undeprived animals, showed that interruption of visual deprivation during both the early or the late stages of postnatal development restores the normal density of the above peptidergic neurons.
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PMID:Interruption of visual deprivation during development restores the normal density of peptidergic neurons in the rat visual cortex. 896 70

The present study describes the expression pattern of somatostatin receptor genes during the development of rat cerebellum. Characterization of somatostatin receptors was carried out by binding studies using receptor subtype-selective ligands in the germinative epithelium and granule cell layer of the cerebellum from postnatal day 4 (P4) to P21 and in granule cell cultures. Quantitative reverse transcription-PCR carried out for the five receptor subtype mRNAs in cerebellar extracts showed that sst1 mRNAs are predominant at the end of gestation. A transient high expression of the sst2 gene was observed from P7 to P14. In parallel, high levels of binding sites sensitive to sst2 ligands were detected in the granule cell germinative epithelium and in granule cell cultures. sst3 mRNAs rapidly increased from P14 and became the predominant form at P21, but respective binding sites were not detected. Whereas sst4 mRNA levels were generally low, those of sst5 were nearly undetectable. Reverse transcription-PCR carried out in granule cell cultures revealed the relative abundance of sst mRNAs as follows: sst2 > sst1 > sst3 = sst4. sst5 mRNA was undetectable. The results show the expression of four somatostatin receptor genes, but only three receptors (sst1, sst4, and mainly sst2) were detected as binding sites during cerebellar development.
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PMID:Differential expression of multiple somatostatin receptors in the rat cerebellum during development. 916 18

The mammalian visual cortex contains morphologically diverse populations of interneurons whose neurochemical properties are believed to be regulated by neurotrophic factors. This requires the expression of neurotrophin receptors. We have analysed whether brain-derived neurotrophic factor (BDNF), its receptor trkB and the NT-3 receptor trkC are expressed in interneurons of rat visual cortex in vivo, and in organotypic visual cortex cultures, paying particular attention to the subsets of neuropeptidergic neurons. In situ hybridization in combination with immunofluorescence for calcium-binding proteins and neuropeptides revealed that BDNF is not expressed in interneurons in vivo or in vitro. For the neurotrophin receptors we found in vivo at postnatal day 70 (P70) that approximately 80% of the parvalbumin-immunoreactive (-ir), but only 50% of the intensely calbindin-ir, and only 20% of the calretinin-ir neurons express trkB. Double labelling with neuropeptides revealed that approximately 50% of the neuropeptide Y-ir and approximately 50% of the somatostatin-ir neurons express trkB in a laminar-specific way. Only 25% of the vasoactive intestinal polypeptide (VIP)-ir neurons coexpress trkB. The coexpression of neuropeptide Y with trkB, but not with BDNF or trkC, was confirmed with a double in situ hybridization. In contrast, the percentages differed in the immature cortex; at P14 70% of the NPY-ir neurons and 46% of the calretinin-ir neurons revealed trkB expression, while the ratio for calbindin-ir cells was fairly constant (59%). From the interneuron populations studied, only 12% of the parvalbumin-ir neurons expressed trkC. A triple labelling revealed that some neurons coexpressed both trk mRNAs, while others had only trkC. The analysis of interneurons in organotypic cultures yielded very similar results. The results indicate that trkB ligands synthesized by pyramidal neurons influence neuropeptide or calcium-binding protein expression in a paracrine or transsynaptic manner. However, in contrast to current belief, in the adult only about half of all interneurons appear responsive to trkB ligands. Although the proportion is higher in the immature cortex, not all of the interneurons appear neurotrophin-receptive. With regard to the presence or absence of neurotrophin receptors, the molecular heterogeneity of GABAergic interneurons in the visual cortex is higher than currently assumed, and the responsiveness to neurotrophins changes with development in a cell type-specific way.
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PMID:Expression of TrkB and TrkC but not BDNF mRNA in neurochemically identified interneurons in rat visual cortex in vivo and in organotypic cultures. 1010 14

Caldendrin is a novel calcium-binding protein confined to the somatodendritic compartment of neurons. Here we have studied the expression pattern of caldendrin in the rat retina. First we assessed the distribution of caldendrin transcripts in the adult and developing retina by in situ hybridization. In the adult retina, transcripts are expressed mainly in the inner half of the inner nuclear layer (INL) and to a lesser extent in the ganglion cell layer (GCL). During development labeling of the inner part of the cytoblast layer, where amacrine cells reside, is already present at postnatal day 1 (P1). The intensity of hybridization signal in this sublamina of the developing INL increases up to P8, whereas significant labeling in the GCL was first found at P14, coinciding with eye opening. Immunodetection with a polyclonal antibody revealed intensive staining of cells in the inner retina, which are presumably mainly amacrine and significantly fewer bipolar and ganglion cells. All parvalbumin-containing All amacrines were immunopositive for caldendrin. Colocalization with calbindin was found in cone bipolar cells, the majority of AII amacrines, and calbindin-positive cells in the GCL. In the GCL, caldendrin was also colocalized with calretinin-immunopositive cells. Most caldendrin-positive amacrine cells in the adult rat retina were glycinergic and only a few were GABAergic. In retinal flat mounts, it was confirmed that less than 10% of retrogradely labeled retinal ganglion cells (RGC) are caldendrin-positive. Caldendrin immunoreactivity does not colocalize with tyrosine hydroxylase, VIP, substance P and somatostatin immunoreactivity. In summary, caldendrin expression is regulated differentially in retinal cell types during development and is restricted to a subpopulation of amacrine, bipolar, and ganglion cells, suggesting specific functions in the developing and mature retina.
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PMID:The cytoskeleton-associated neuronal calcium-binding protein caldendrin is expressed in a subset of amacrine, bipolar and ganglion cells of the rat retina. 1055 36

The present study was aimed at identifying somatostatin receptor subtypes on the basis of their ligand-binding properties in the rat somatosensory cortex during fetal and postnatal development. Characterization of somatostatin-binding sites was performed in individual cortical layers by using three radioligands and eight competitors with known selectivities for the five somatostatin receptor subtypes. Binding sites sensitive to sst2-selective ligands were detected with high densities in the intermediate zone of the fetal cortex. From embryonic day 21 to 21 days postnatal (P21), mixed populations of receptors were detected in the cortical plate and emerging layers I-VI. Putative sst2 receptors were detected throughout the entire period but displayed different affinities for somatostatin and analogs, and a different sensitivity to GTP, depending on the developmental stage and the cortical layer considered. High densities of binding sites exhibiting characteristics of the sst1, sst3/5, and sst4 receptor subtypes were observed from P4 to P7, P7 to P14, and P7 to P21, respectively. In addition, each type of site exhibited a particular distribution pattern across the cortical layers that varied during the development. In the adult cortex, binding sites with sst1 and sst2 receptor characteristics were predominant. This study provides evidences of developmental expression windows of four sst receptor subtypes in selected areas of the rat cerebral cortex.
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PMID:Identification of multiple somatostatin receptors in the rat somatosensory cortex during development. 1080 21

The suprachiasmatic nucleus (SCN), a central circadian oscillator of mammals, contains various peptides arranged in the compartment specific manner. In the present study, we examined a distinct population of neurons in the central part of the SCN. In situ hybridization histochemistry has demonstrated that these neurons coexpressed both preprosomatostatin (PPSS) and preprotachykinin A (PPT-A) mRNAs, but the developmental expression profiles were different among two. PPSS mRNA first appeared in the SCN at postnatal day 1(P1). The intensity and number of PPSS mRNA signals increased and peaked at P7-P14 and gradually decreased as to adult age (P56). However, PPT-A mRNA-positive appeared late at P7, and gradually increased up to P56. These findings suggest that neurons encoding both the PPSS and PPTA genes first express PPSS and then express PPT-A at a later stage of maturation.
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PMID:Different developmental profiles of the expression of preprosomatostatin and preprotachykinin-A mRNAs in rat SCN neurons. 1128 68


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