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 intrastriatal infusion of relatively low doses of quinolinic acid (Quin, 4-10 nmol/h) for 1 or 2 weeks induced time-dependent degeneration of neuronal cells. We examined the effects of these infusions on discrete cellular populations. The distribution of somatostatin (SOM)-positive neurons labelled by immunocytochemistry or by NADPH-diaphorase histochemistry and of cholinergic cells stained by acetylcholinesterase was quantified in the peripheral portion of the lesioned area. SOM-positive cells did not appear selectively spared by Quin infusion. The proportion of SOM- and NADPH-diaphorase-positive neurons killed by exposure to Quin was similar to or higher than the percentage of total neurons degenerated (from 30 to 85%). A selective sparing of cholinergic cells was observed in all conditions examined; perfusion of 6 nmol/h for a week induced 65% of cell death while not more than 30% of cholinergic neurons were killed. Thus, the neurochemical similarity between the degenerative effects of intrastriatal Quin and Huntington's disease (HD) did not appear confirmed by the chronic perfusion of low doses of Quin for SOM-positive neurons, whereas an analogy between Quin's effects and HD was suggested by the pattern of AChE staining.
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PMID:Chronic infusion of quinolinic acid in rat striatum: effects on discrete neuronal populations. 138 77

The anterior major pelvic ganglion (AMPG) of the male guinea-pig has been found to consist of three principal components. The presence of a cholinergic component was determined by the demonstration of cytoplasmic and nerve fibre acetylcholinesterase activity. A noradrenergic component was demonstrated by immunoreactivity (IR) of the catecholamine-synthesising enzymes tyrosine hydroxylase (TH) and dopamine-beta-hydroxylase (DBH) in neuronal perikarya. The AMPG also had a peptidergic component which may or may not sub-classify the cholinergic and noradrenergic components. Neuropeptide Y (NPY)-, vasoactive intestinal peptide (VIP)-, and atrial natriuretic factor (ANF)-immunoreactivities were seen in neuronal perikarya, nerve fibres and nerve terminals/varicosities, while somatostatin (SOM)-IR was restricted to neuronal perikarya. Substance P (SP)-IR was present in a dense network of varicose nerve fibres. However, on a rare occasion SP-IR was observed in neuronal perikarya. Enkephalin (ENK)-IR occurred in a sparsely distributed plexus of varicose nerve fibres. The analysis of adjacent serial sections demonstrated distinct patterns of neuropeptide coexistence in AMPG neurons. NPY-IR was colocalised to a subpopulation of TH-IR neuronal perikarya. NPY-IR was also colocalised with VIP-IR in non-TH-IR neuronal perikarya. VIP-IR occurred together with AChE in particular neuronal perikarya. The relationship between immunoreactive neuronal perikarya and immunoreactive nerve terminals was investigated. SP-IR nerve terminals were closely related to neuronal perikarya exhibiting VIP-, NPY-, or TH-IR. TH-IR neuronal perikarya were also abutted by ENK-IR nerve terminals. VIP- and NPY-immunoreactive neuronal perikarya were abutted by two nerve terminal types: one immunoreactive for VIP, the other for NPY. DBH-IR neuronal perikarya received AChE-positive varicosities while AChE-positive neurons were abutted by DBH-IR varicose nerve fibres. AChE-positive varicosities were also closely related to neuronal perikarya possessing VIP-IR and AChE activity.
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PMID:Specific patterns of immunoreactivity in neuronal elements of the anterior major pelvic ganglion of the male guinea-pig. 168 Aug 42

This study examines to which extent developing dentate granule cells grafted into excitotoxic lesions of the adult rat fascia dentata can be appropriately innervated by the host brain. The lesions were induced by focal injections of ibotenic acid (IA) and resulted in localized dentate and hippocampal neuronal cell death, but sparing of the afferent connections, now deprived of their targets. One week later pieces of fascia dentata from newborn rats were grafted into the lesions. After 6 weeks to 9 months the recipient brains were processed and analyzed by cell stain, histochemistry, immunohistochemistry, anterograde nerve fiber degeneration methods, and electron microscopy. Dentate grafts survived well in the lesion area and became organo-typically organized. They contained the normal nerve cell types of the fascia dentata and hilus (CA4), including the peptidergic somatostatin-, cholecystokinin- and enkephalin-reactive ones. The grafts were innervated by AChE-positive, cholinergic fibers from the host septum, and perforant path fibers from the host entorhinal area. The presence of the latter were demonstrated by Timm staining and light and electron microscopy of anterograde axonal degeneration. When the extent and density of the host perforant path innervation was examined and mapped at the electron microscopical level the grafts in the IA-lesions were found to receive a more extensive and denser host innervation than grafts placed in the normal fascia dentata of adult rats without a preceding axon-sparing ibotenic acid lesion. In this way the results demonstrate that certain lesion types can enhance the innervation of intracerebral grafts by already mature neural pathways of the point-to-point type.
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PMID:Enhanced host perforant path innervation of neonatal dentate tissue after grafting to axon sparing, ibotenic acid lesions in adult rats. 274 7

In previous studies, fibers demonstrating somatostatin-like immunoreactivity were observed in the outer half of the molecular layer of the dentate gyrus in the rat and monkey. They occupy the same region as those of the perforant pathway that originates in the entorhinal cortex. Numerous somatostatin immunoreactive neuronal cell bodies were also observed in the hilar region, though stained axonal profiles could not be followed from these cells into the molecular layer. In the present study, several experimental procedures were employed to determine the origin of the somatostatin-positive fibers in the molecular layer. Transection of the perforant path fibers resulted in such characteristic changes as shrinkage of the molecular layer and sprouting of AChE-positive fibers. There was no apparent decrease, however, in the density of somatostatin-positive fibers. In fact, since the stained fibers occupied a narrower band in the shrunken molecular layer, their density appeared greater. Injections of kainic acid into the hilar region produced a lesion of hilar neurons, including those positive for somatostatin. In the region of cell loss, there was a marked reduction of somatostatin-immunoreactive fibers in the ipsilateral molecular layer, with no detectable changes in the homotopic contralateral molecular layer. The distribution of AChE fibers, which presumably have an extrinsic origin, was not altered by the treatment. In a final series of experiments, the retrograde tracer wheat germ agglutinin-horseradish peroxidase (WGA-HRP) was injected into the hilar region and sections were prepared for the simultaneous demonstration of the tracer and of somatostatin-like immunoreactivity. Somatostatin-positive neurons demonstrating WGA-HRP reaction product were observed primarily in the ipsilateral hilar region, but a few double-labeled cells were also seen in the same area of the contralateral side. These studies indicate that a population of intrinsic neurons located in the polymorphic layer of the dentate gyrus projects to the outer half of the ipsilateral molecular layer. A similar, but very much smaller, projection also extends to the contralateral dentate gyrus. Taken together, these projections appear to account for much of the somatostatin-like immunoreactivity in the molecular layer of the dentate gyrus.
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PMID:An experimental analysis of the origins of somatostatin-like immunoreactivity in the dentate gyrus of the rat. 287 80

The chicken retina has been used to examine the toxicity of a highly reactive chemical analog of choline, ethylcholine mustard aziridinium ion (ECMA). Following a single intravitreal injection, retinas were analyzed biochemically for CAT and AChE activities, and GABA, glycine, and dopamine levels. Retinas were also examined using histofluorescence for dopamine histochemistry, for AChE, and immunohistochemistry with antibodies to CAT, tyrosine hydroxylase, GABA, 5-HT, Leu-enkephalin, and somatostatin. A dose of 50 nmol ECMA caused a prolonged 70% depletion of CAT activity and a 40% depletion of AChE activity. The other biochemical parameters were unchanged. This result corresponds to the morphological finding that 2 populations of cholinergic cells were destroyed and that the AChE activity associated with their terminal arbors was lost. A third population of cholinergic cells, located towards the middle of the inner nuclear layer, was resistant to the toxic effects of ECMA. The other cell types, except for somatostatin-immunoreactive cells and photoreceptors, which showed transient effects, were unaffected. ECMA therefore appears to be a highly specific toxin for cholinergic cells in the retina.
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PMID:The toxic effects of ethylcholine mustard aziridinium ion on cholinergic cells in the chicken retina. 288 Sep 36

The survival and cellular and connective organization of intracephalic transplants of developing, freeze-stored rat hippocampal tissue were examined. Blocks of tissue containing the hippocampus and fascia dentata were obtained from late embryonic (E16-E22) and early postnatal rats (P0-P4) and immersed in a tissue culture medium with 10% of the cryoprotective agent DMSO, frozen at a cooling rate of approximately 1 degree C/minute, and stored for 1-226 days in liquid nitrogen. After quick thawing and washing out of the DMSO the tissue blocks were transplanted to the brain of adult rats. From 2 weeks to 3 months later the recipient brains were processed histologically. The cellular and connective organization of the transplants and their interaction with the host brains were analyzed after thionin cell staining, Timm's staining for hippocampal and dentate afferents, immunohistochemical staining for enkephalin-, CCK-, and somatostatin-reactive neurons and afferents, AChE staining for cholinergic afferents, and silver stains for fiber architectonics and tracing of connections by anterograde axonal degeneration. Freeze-storage narrowed the range of donor ages with good transplant survival. The best surviving hippocampal and dentate transplants thus came from 17-21-day-old embryos. There was no correlation between the length of storage and survival. Structurally the transplants of stored tissue were more frequently fragmented than the transplants of fresh tissue when located outside the brain parenchyma in the brain ventricles. This was in accordance with the results of a previous study of grafts of freeze-stored and fresh hippocampal tissue placed in the anterior eye chamber. Despite the decrease in survival and the tendency for fragmentation many well-structured and organotypically organized hippocampal and dentate transplants were recovered corresponding to the donor ages E19-E21. In addition to the main cell types (granule cells and pyramidal cells) the freeze-stored transplants also contained peptidergic nerve cells reacting for CCK, somatostatin, and enkephalin. The organization of the intrinsic nerve connections and the exchange of connections with the host brain were similar for transplants of stored and fresh tissue. Besides the consistent innervation of the hippocampal and dentate transplants by host cholinergic afferents monitored by AChE staining, several appropriately located dentate transplants thus sent mossy fibers to the host CA3. Others received host perforant path projections. A CA3-associated transplant projection to the denervated perforant path zones in the host fascia dentata was also observed.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Intracephalic transplants of freeze-stored rat hippocampal tissue. 378 12

This study examined the cellular and connective organization of hippocampal tissue taken from 6-8-day-old rats and cultured by the roller tube technique for 3-6 weeks. In the cultures containing the fascia dentata and the hippocampus proper (CA1, CA3, CA4) the main cell and neuropil layers were organotypically organized when observed in ordinary cell stains. The normal distribution of smaller cell populations of AChE-positive neurons and somatostatin-reactive neurons was demonstrated by histochemical and immunohistochemical methods. Both cell types were mainly confined to str. oriens of CA3 and CA1 and the dentate hilus (CA4). Individual dentate granule cells and hippocampal pyramidal cells were injected with lucifer yellow and HRP, revealing great stability of the dendritic patterns of these cells in the culture condition. The same was found for the axonal branching and termination of HRP-filled mossy fibers arising from an HRP-injected granule cell. The preservation of organotypic afferent patterns in the cultures was also shown by Timm staining of the terminal distribution of the mossy fiber system. Mossy fiber terminals, with characteristic ultrastructural features verified in the electron microscope, were thus found in the hilus (CA4) and along the CA3 pyramidal cell layer onto the CA3-CA1 transition. Depending on the amount of dentate tissue relative to CA3 the terminals could stop before reaching CA1 (small fascia dentata) or take up additional intra and infrapyramidal locations along CA3 (small CA3). In cultures with a gap in the CA3 pyramidal cell layer some mossy fiber terminals were found in contact with the CA3 pyramidal cells beyond the gap. In all cultures there was an aberrant projection of supragranular mossy fibers. This projection is analogous to the one known from lesion and transplant studies to form in the absence of the entorhinal perforant path input to the dentate molecular layer. Also, in accordance with these studies the Timm staining pattern of the outer parts of the dentate molecular layer and the entire molecular layer of the hippocampus was altered corresponding to the spread of afferents normally confined to the inner zone of the dentate and str. radiatum of CA3 and CA1. Possibly as a consequence of the lack of normal targets for projections from CA1, this subfield contained an unusually dense Timm staining suggestive of autoinnervation.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Cellular and connective organization of slice cultures of the rat hippocampus and fascia dentata. 614 64

An account is given of the authors' work with isolated adrenal chromaffin cells to study the synthesis, storage and release of catecholamines and of a number of neuropeptides endogenous to the adrenal medulla. A review of other studies in the literature with the isolated chromaffin cell system is included. It is seen that the isolated chromaffin cells are a convenient in vitro system well-suited to studies of basic release mechanisms. The isolated adrenal chromaffin cells maintain high levels of catecholamines and opiates and release them by exocytosis. The cells have both nicotinic and muscarinic receptors but only the nicotinic are involved in the agonist-evoked release of catecholamines (EC50 nicotine 5 X 10(-6) M: ACh 5 X 10(-5) M). The cells can synthesize AChE and selectively release the 10S molecular form by a mechanism different from exocytosis. Substance P (SP) modulates the secretion of catecholamines and ATP evoked by ACh or nicotine but not that evoked by K+ or veratridine. SP appears to interact with the nicotinic receptor-ionophore complex to regulate Na+ entry. SP receptors on the chromaffin cells show similar structural requirements to SP receptors in other SP responsive tissues. Binding studies on isolated chromaffin cell membranes with [4-3H-Phe]SP have shown specific binding in the nM range. In addition, at high concentrations of ACh, SP protects against nicotinic receptor desensitization. Since SP is contained in the splanchnic nerve terminals that innervate the medulla, the demonstration of SP action and SP receptors on the chromaffin cells suggests a physiological role for SP in the regulation of secretion from the adrenal medulla. Somatostatin (SS) and a number of SS analogues also inhibit release, but are approximately 15-fold less potent than SP. Leu- and Met-enkephalin, which are co-stored with adrenaline in the bovine adrenal medullary cells produce a non-specific inhibition of the nicotine-evoked release of CA, but enhance the basal release of endogenous catecholamines by a mechanism that is Ca2+-dependent, stereospecific and reversible by naloxone and naltrexone. The implication of these peptide-amine interactions for physiological processes regulating homeostasis in the adrenal are discussed.
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PMID:Use of isolated chromaffin cells to study basic release mechanisms. 618 74

Transplantation of embryonic neocortex into adult host neocortex leads to the survival of many donor cells, with the subsequent differentiation of the cortical neurons within a loosely laminated cellular pattern. We wanted to know whether peptide-containing neurons that are known to exist in normal neocortex would survive in the transplants, and if so, whether they would differentiate into morphological cell types that normally contain these peptides in cortex. By 30 days after transplantation, the implants were well vascularized and the donor neurons appeared healthy in Nissl-stained preparations. AChE-positive axons grew across the interface and innervated the transplant in moderate densities. Immunocytochemical localization of peptides in the transplant revealed that processes containing the four peptides normally present in cortex also develop in the transplants. These were vasoactive intestinal polypeptide, cholecystokinin, pancreatic polypeptide and somatostatin. Other peptides not yet demonstrated in and presumably not present in neocortex, did not develop in the transplants. These included alpha-melanocyte stimulating hormone, arginine-vasopressin, corticotropin releasing factor, beta-endorphin and substance P. The results demonstrate that peptide-immunoreactive neurons survive in neural transplants, where they develop complicated patterns of axonal arborization. The conditions used in these experiments produced no evidence that peptidergic neurons within the transplant grow out of the transplant and into the host brain within six weeks. Similarly, host peptidergic axons were never seen crossing the interface zone and entering the transplant in any significant numbers.
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PMID:The development of peptide-containing neurons within neocortical transplants in adult mice. 620 Aug 65

The present study reveals the presence of a distinct group of cells, resembling reticular thalamic neurones, in the internal capsule during fetal development. This cell population rapidly decreases in size during early infancy and few cells are apparent in the 1-year-old infant. Internal capsule cells are well differentiated, multipolar or polymorphous, AChE (acetylcholinesterase)-reactive neurones. The following specific molecular markers were demonstrated in the neurones of the internal capsule: MAP2 (microtubule-associated protein 2), somatostatin, calbindin-D28K and p75 low-affinity NGF (nerve growth factor) receptor. A group of neurones described here corresponds to the perireticular thalamic nucleus found in certain mammalian species, hitherto unidentified in the primate brain, which may play an important role during development.
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PMID:Transient neuronal population of the internal capsule in the developing human cerebrum. 893 Sep 80


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