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 light microscopic and ultrastructural distribution of somatostatin immunoreactivity has been studied in laminae I-III of the rat cervical spinal cord by means of a bi-specific anti-somatostatin/anti-horseradish peroxidase monoclonal antibody. Immunoreactivity was demonstrated in small rostro-caudally oriented nerve cells of ventral lamina II. Somatostatin-immunoreactive axonal varicosities contained round, agranular, synaptic vesicles and some large granular vesicles. These varicosities established either symmetric or asymmetric synaptic contacts with dendrites, presynaptic dendrites or cell bodies. In the middle third of lamina II, a small number of somatostatin-immunoreactive varicosities were the central elements of type I synaptic glomeruli. Immunoreactivity for somatostatin was also detected in dendritic profiles of laminae II-III. Some of these dendrites were part of synaptic glomeruli, and a small number of them were presynaptic dendrites. The latter were sometimes presynaptic to the central glomerular bouton. The results favor a participation of somatostatin-containing spinal interneurons in the modulation of sensory information.
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PMID:Ultrastructural evidence for the occurrence of two distinct somatostatin-containing systems in the substantia gelatinosa of rat spinal cord. 197 Nov 80

To determine whether biosynthesis of somatostatin is enhanced in the primary sensory neurons by inflammatory pain, we examined the effects of adjuvant inoculation on the content of immunoreactive somatostatin, mainly composed of somatostatin-14 and somatostatin-28, in the dorsal root ganglia and the spinal cord of the rat. The adjuvant inoculation, which produced long-lasting inflammation and hyperalgesia, increased the content of immunoreactive somatostatin, especially somatostatin-14, in the dorsal root ganglia at L4-L6 levels with no change in the dorsal and ventral horns of lumbar enlargement. Such an increase was enhanced by an intrathecal injection of colchicine (0.2 mg) that inhibits axonal flow of somatostatin. Chronic administration of the anti-inflammatory analgesic, sodium diclofenac (3 mg.kg-1.d-1), abolished an adjuvant-induced increase in the content of immunoreactive somatostatin in the dorsal root ganglia. These results suggest that the turnover (biosynthesis and axonal flow) of somatostatin in the primary sensory neurons is enhanced in the presence of persisting inflammatory pain, and support the idea that somatostatin-containing primary afferents are involved in the transmission of pain in the spinal dorsal horn.
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PMID:Somatostatin is increased in the dorsal root ganglia of adjuvant-inflamed rat. 197 11

Cranial and spinal sensory ganglia of the guinea-pig were investigated by means of histochemistry and biochemistry for the presence of catecholamines and catecholamine-synthesizing enzymes. Sensory neurons exhibiting immunoreactivity to the rate-limiting enzyme of catecholamine synthesis, tyrosine hydroxylase (TH), were detected by immunohistochemistry in lumbo-sacral dorsal root ganglia, the nodose ganglion and the petrosal/jugular ganglion complex. The carotid body was identified as a target of TH-like-immunoreactive (TH-LI) neurons by the use of combined retrograde tracing and immunohistochemistry. Double-labelling immunofluorescence revealed that most TH-LI neurons also contained somatostatin-LI, but TH-LI did not coexist with either calcitonin gene-related peptide- or substance P-LI. TH-LI neurons did not react with antibodies to other enzymes involved in catecholamine synthesis, i.e., aromatic amino acid decarboxylase (AADC), dopamine-beta-hydroxylase (D beta H), and phenylethanolamine-N-methyl-transferase (PNMT). Petrosal neurons as well as their endings in the carotid body lacked dopamine- and L-DOPA-LI. Sensory neurons did not display glyoxylic acid-induced catecholamine fluorescence. Ganglia containing TH-LI neurons were kept in short-term organ culture after crushing their roots and the exiting nerve in order to enrich intra-axonal transmitter content at the ganglionic side of the crush. However, even under these conditions, catecholamine fluorescence was not detected in axons projecting peripherally or centrally from the ganglia. Sympathetic noradrenergic nerves entered the ganglia and terminated within them. Accordingly, biochemical analyses of guinea-pig sensory ganglia revealed noradrenaline but no dopamine. In conclusion, catecholamines within guinea-pig sensory ganglia are confined to sympathetic nerves, which fulfill presently unknown functions. The TH-LI neurons themselves, however, lack any additional sign of catecholamine synthesis, and the presence of enzymatically active TH within these neurons is questionable.
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PMID:Catecholamines and catecholamine-synthesizing enzymes in guinea-pig sensory ganglia. 197 3

Hippocampal CA3 neurons from fetal rats were grafted to excitotoxic lesions in the CA3 subfield of the adult rat hippocampus and the formation of graft-host brain nerve connections examined. The excitotoxic lesions were induced by localized, stereotaxic injection of ibotenic acid (IA), a glutamic acid agonist, into CA3 of the dorsal hippocampus. The result was a so-called axon-sparing lesion with localized degeneration of nerve cells, but preservation of the extrinsic afferent fibers, now deprived of their targets. One week after the lesion a suspension of embryonic (E18-20) CA3 cells was grafted to the lesion site. Six weeks or more later the recipient brains were processed and analyzed by ordinary cell stains, histochemistry for acetylcholinesterase (AChE) and heavy metals (Timm staining), immunohistochemistry for the neuropeptides cholecystokinin and somatostatin and glial fibrillary acidic protein (GFAP) for astroglia, electron microscopy, and axonal tracing with retrogradely axonal transported fluorescent dyes or lesion-induced, anterograde degeneration combined with silver staining or electron microscopy. More than 90% of the grafts survived. They contained the normal types of CA3 neurons, which are mainly pyramidal cells, in addition to some normal, peptidergic, cholecystokinin- and somatostatin-reactive neurons. The grafts were innervated by AChE-positive, host cholinergic fibers, Timm-positive mossy fiber terminals from the host fascia dentata, and host commissural fibers traced by axonal degeneration. Efferent transplant projections were traced to the ipsilateral host CA1 (Schaffer collaterals) and the contralateral host hippocampus by retrograde axonal transport of fluorochromes injected into these host brain areas. All grafts analyzed by electron microscopy contained axonal varicosities resembling axonal growth cones even after long survival times. The results demonstrate that fetal rat hippocampal neurons, grafted to excitotoxic, axon-sparing lesions in the adult brain, can become both structurally and connectively well incorporated in the mature host central nervous system.
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PMID:Grafting of fetal CA3 neurons to excitotoxic, axon-sparing lesions of the hippocampal CA3 area in adult rats. 239 68

Neurons surrounding the central canal in sacral spinal segments were functionally characterized on the basis of somatic and/or visceral afferent input, then intracellularly marked with horseradish peroxidase (HRP). Tissue sections containing portions of HRP-stained neurons were subsequently immunohistochemically examined for the presence of contacts made by axonal enlargements containing vasoactive intestinal polypeptide (VIP), substance P (SP), somatostatin (SS), Leu-enkephalin (ENK), or serotonin (5-HT). ENK-and 5-HT-containing enlargements were found to contact all neurons examined. SP and SS terminals contacted fewer neurons, and were not associated with specific functional classes. On the other hand, VIP-containing fibers contacted only those neurons receiving visceral afferent input, thus supporting the contention that VIP is contained in a population of visceral afferent fibers projecting to the gray matter surrounding the central canal at sacral levels.
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PMID:Immunohistochemistry of synaptic input and functional characterizations of neurons near the spinal central canal. 241 42

Combined neuroanatomical techniques were used to examine the organization of the striatal projection to the substantia nigra in the rat. Both double anterograde axonal tracing methods (Phaseolus vulgaris leuco-agglutinin (PHA-L) and 3H-amino acid tract tracing) and double fluorescent retrograde axonal transport tracing methods were used to examine the relationship among striatal neurons projecting to separate areas of the substantia nigra. Additionally, the distributions of retrogradely labeled striatonigral projection neurons were charted relative to the neurochemically distinct striatal "patch" compartment, identified by substance P- or leu-enkephalin-like immunoreactivity, and the complementary "matrix" compartment, identified by somatostatin-like immunoreactive fibers. These studies show two distinct types of organization in the striatonigral projections. One type is topographic in that the mediolateral relationships among these striatal efferent neurons are roughly maintained by their termination patterns in the substantia nigra, while the dorsoventral relationships are inverted. Projections from any part of the striatum, however, are distributed throughout the rostrocaudal axis of the substantia nigra. Despite their general topographic organization, the variable and dispersed nature of such projections from individual striatal loci results in partial overlap of afferent fields from separate striatal areas. The second type of organization is nontopographic and provides a different system for convergence of inputs from separated striatal areas that is superimposed on the rough topographic system. In this other projection system the mediolateral and dorsoventral relationships typical of the topographically ordered system are not maintained and are sometimes reversed. For example, PHA-L injected into the dorsal striatum labels a topographic (inverted relationship) projection to the ventral substantia nigra pars reticulata but also a smaller and separate projection to the dorsal pars reticulata and adjacent pars compacta. Retrograde tracer deposits in the pars compacta label neurons in the ventral striatum (the inverted relationship) but also clusters of neurons in the dorsal striatum. These clusters are in the neurochemically defined patch compartment whereas neurons in the matrix are labeled by injections into the pars reticulata. The dendrites of both retrogradely filled patch and matrix neurons are confined to the compartment containing their cell bodies, suggesting a restriction that would functionally segregate extrinsic striatal afferents shown in other studies to be confined to either patches or matrix.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:The neostriatal mosaic. I. Compartmental organization of projections from the striatum to the substantia nigra in the rat. 241 39

We have used light and electron microscopic immunocytochemical techniques to study the distribution and morphology of neurons that contain vasoactive intestinal polypeptide-like immunoreactivity (VIP-Ir) in the adult rat striatum. VIP-Ir cells were sparsely distributed throughout all rostrocaudal levels of the striatum. Cell bodies were of medium size (12-17 microns) and gave rise to three to five primary dendrites, which branched close to the soma and became varicose. These dendrites appeared aspiny at the light microscope level and could be traced up to 250 microns in length. Dendrites frequently traversed axonal bundles in the striatum, a pattern not exhibited by neurons containing somatostatin-like or substance P-like immunoreactivity. In several instances, very fine varicose processes arborized extensively within 40 microns of the VIP-Ir soma; these may represent axons. In thin-sectioned preparations, examined under the electron microscope, the nucleus of VIP-Ir neurons was eccentrically located and showed several deep invaginations. Immunoreactive dendrites of VIP-Ir cells appeared virtually spine-free. Synapses with asymmetric or symmetric junctional specializations were present on the dendritic surface. Several VIP-Ir varicosities were found to terminate on the VIP-Ir cell body, forming synaptic junctions with symmetric specializations; these synapses may derive from recurrent collaterals. VIP-Ir cells thus resemble other aspiny striatal neurons considered likely to be local circuit neurons.
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PMID:Morphology of striatal neurons containing VIP-like immunoreactivity. 243 35

In previous immunohistochemical studies in the rat and monkey, a system of somatostatin-positive neurons and fibers was observed in the dentate gyrus of the hippocampal formation. In both species, somatostatin-immunoreactive cell bodies are located primarily in the deep or polymorphic layer of the dentate gyrus, and they give rise to a fiber system that terminates principally in the outer two-thirds of the molecular layer. In the present study, we employed the same antisera and staining procedures to determine whether the organization of the somatostatin system in the human dentate gyrus is similar to that seen in the rat and nonhuman primate. Sections of human postmortem brain material incubated with antisera directed against somatostatin 28 (S320) or somatostatin 28 (S309) demonstrated a heterogeneous population of immunoreactive cells in the hilar region of the human dentate gyrus. Fiber staining was observed both in the hilar region and throughout the molecular layer, but the densest fiber and terminal plexus were observed in the outer two-thirds of the molecular layer. In addition, there were forms of somatostatin-immunoreactive profiles in the human sections that were not previously observed in the rat or monkey. Immunoreactive, grapelike clusters of apparently large, axonal varicosities were commonly observed, for example, as were dendritic profiles containing typical dendritic spines. In general, however, staining for somatostatin immunoreactivity in the human dentate gyrus presented a picture qualitatively similar to that observed in the rat and monkey. Thus, immunohistochemical methods have allowed the analysis of a chemically defined neural system in the human brain that has been extensively studied in rat and monkey brains with both experimental and immunohistochemical methods. That the pattern of labeling in the human sections closely parallels that observed in the experimental animals provides support for the contention that immunohistochemical methods can reliably be employed to determine the normal neuroanatomical organization of the human brain. These methods may also be particularly applicable for the analysis of pathological brain conditions. In particular, alterations of the hippocampal somatostatin system have been associated with both Alzheimer's disease and temporal lobe epilepsy. It would be of interest, therefore, to apply immunohistochemical procedures to determine whether the anatomical organization of the human hippocampal somatostatin system is altered in these diseases.
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PMID:Distribution of somatostatin immunoreactivity in the human dentate gyrus. 245 24

In order to understand better the neuronal circuitry involved in the regulation of gut functions, we have studied the distribution and projections of those enteric neurons in the rat intestines that contain vasoactive intestinal peptide (VIP), neuropeptide Y (NPY), galanin, substance P (SP), calcitonin gene-related peptide (CGRP), gastrin releasing peptide (GRP), somatostatin and enkephalin. The origin of the peptide-containing nerve fibers was examined by immunocytochemistry after extrinsic denervation. Most of them were found to be intramural in origin, each population displaying its own characteristic topographic distribution. The projections of each neuronal population were studied immunocytochemically by examining the subsequent axonal degeneration after local severing of nervous pathways. This study revealed that myenteric neurons issue predominantly descending projections to other myenteric ganglia and to the muscle layers. Submucous neurons project to other submucous ganglia and to the mucosa and submucosa. Most of these neurons issue both ascending and descending projections. The projection distances varied considerably between the different neuronal populations, the majority being in the range of 4-10 mm. Myenteric GRP and galanin neurons in the small intestine issued the longest projections, 20 and 15 mm, respectively. The shortest projections were those issued from myenteric VIP/NPY neurons and submucosal galanin and GRP neurons in the small intestine and from submucosal VIP neurons in the large intestine (2 mm in length). On the whole our results on the projections of enteric neurons in the rat agree with observations in the guinea pig and dog. However, there are species differences that remain to be explained.
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PMID:Projections of enteric peptide-containing neurons in the rat. 247 1

Several immunogold techniques were used to determine the ultrastructural localization of calcitonin gene-related peptide (CGRP), tachykinin, somatostatin, and gamma-amino-butyric acid (GABA) immunoreactivity in the dorsal horn of rat spinal cord. The immunocytochemical reactions were carried out directly on ultrathin sections from non-osmicated frozen tissue, non-osmicated low temperature-embedded (Lowicryl K4M) tissue, and osmicated epoxy-embedded material. Preservation of ultrastructural morphology and immuno-labeling efficiency were compared. Morphology of subcellular organelles was relatively good in ultra-thin frozen sections, which showed the highest immunoreactivity. However, only very small samples of tissue could be examined. Although there was relatively good immunolabeling in the Lowicryl K4M-embedded tissue, the ultrastructure of the neuropil, and particularly that of synapses, was poorly maintained. In contrast, the osmicated epoxy-embedded material offered optimal morphological preservation together with accurate subcellular localization of all antigens under study. The latter approach thus enabled clear visualization of CGRP, tachykinin, and somatostatin immunoreactivity restricted to large dense-cored vesicles (90-150 nm diameter) in many axonal and synaptic profiles in the superficial layers of the dorsal horn. CGRP- and tachykinin-positive profiles were also present in the tract of Lissauer. GABA immunoreactivity was present mainly in axons and terminals, and less frequently in somatic and dendritic profiles. In terminals, which often formed symmetrical synapses on immunonegative dendritic profiles, it was associated with small (30-60 nm diameter) clear vesicles and mitochondria. Double immunolabeling was possible on all preparations, but the osmicated, epoxy-embedded material clearly showed co-localization of peptides, especially of CGRP and tachykinins, within the same dense-cored vesicles in axonal fibers and/or terminals. On the other hand, peptide and GABA immunoreactivity were consistently seen in different nerve profiles. In a few cases, GABAnergic terminals were seen to synapse on tachykinin-positive fibers.
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PMID:Ultrastructural localization of neuropeptides and GABA in rat dorsal horn: a comparison of different immunogold labeling techniques. 256 4


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