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Biomedical subjects

S R Vincent

Publications and source records attributed to S R Vincent.

At least 109 records · Page 6Linked to original sources
PubMed1985

Central somatostatin systems revealed with monoclonal antibodies.

The distribution of central neurons displaying somatostatin immunoreactivity was studied using three monoclonal antibodies to cyclic somatostatin. The sensitive ABC immunoperoxidase technique was employed. A large number of positive cell groups including many previously undescribed populations were detected throughout the brain and spinal cord. Telencephalic somatostatin neurons included periglomerular cells in the olfactory bulb, mitral cells in the accessory olfactory bulb, and multipolar cells in the anterior olfactory nuclei, neocortex, amygdala, hippocampus, lateral septum, striatum, and nucleus accumbens. Within the hypothalamus, positive neurons were found in the periventricular, suprachiasmatic, and arcuate nuclei, and throughout the anterior and lateral hypothalamus. The entopeduncular nucleus and zona incerta contained many positive neurons, and the lateral habenula had a dense terminal field suggesting a pallidohabenula somatostatin pathway. Somatostatin neurons were also found in association with many sensory systems. Positive cells were present in the superior and inferior colliculi, the ventral cochlear nuclei, the ventral nucleus of the lateral lemniscus, nucleus cuneatus, nucleus gracilus, and the substantia gelatinosa. Various cerebellar circuits also displayed somatostatin immunoreactivity. Golgi cells throughout the cerebellar cortex were intensely stained, and some Purkinje cells in the paraflocculus also showed a positive reaction. Positive fibers were present in the granular layer and large varicose fibers were present in the inferior cerebellar peduncle. Many nuclei known to project to the cerebellum, including the nucleus reticularis tegmenti pontis, the medial accessory inferior olive, the nucleus prepositus hypoglossi, and many areas of the reticular formation contained positive neurons. These studies demonstrate that these new monoclonal antibodies are of great value for the study of central somatostatin systems. Previously described somatostatin systems are readily detected with these antibodies, and in addition, many otherwise unrecognized somatostatin cell groups have been discovered.

Animals↗
PubMed1984

Peripheral projections and neuropeptide coexistence in a subpopulation of fluoride-resistant acid phosphatase reactive spinal primary sensory neurons.

Combined retrograde axonal tracing with the fluorescent dye Fast Blue and fluoride-resistant acid phosphatase (FRAP) histochemistry revealed that the FRAP-containing sensory neurons project to both somatic and autonomic peripheral nerves. Furthermore, the combination of indirect immunohistochemistry after colchicine treatment and FRAP histochemistry showed that a population of FRAP-containing sensory neurons are also substance P, cholecystokinin or somatostatin positive.

Acid Phosphatase↗
PubMed1984

Effects of cysteamine on pain behaviour and on somatostatin- and substance P-like immunoreactivity in the substantia gelatinosa of the rat.

Immunohistochemical studies on rats showed cysteamine to deplete immunoreactive somatostatin, but not substance P, in the substantia gelatinosa of the spinal trigeminal nucleus and spinal cord. The effect of cysteamine treatment on chemical pain was investigated using capsaicin as the pain-producing stimulus. Thermal pain was assessed with a hot plate test after cysteamine treatment. It was found that cysteamine did not alter the hind paw lick latency in the hot plate test or the number of forepaw wipes after application of a drop of capsaicin into the cornea, compared to normal animals. In capsaicin-treated animals a significantly lower number of forepaw wipes were seen after corneal capsaicin application. However, in cysteamine-treated animals slower wiping was observed compared to untreated and capsaicin-treated animals. This suggests that somatostatin may be of importance for the modulation of nociceptive information, although it is not a major pain transmitter.

Animals↗
PubMed1984

Corticotropin-releasing factor (CRF) immunoreactivity in the dorsolateral pontine tegmentum: further studies on the micturition reflex system.

A cluster of neurons in the pontine tegmentum thought to correspond with the micturition reflex center was retrogradely labeled following the injection of the fluorescent tracer True Blue into the sacral spinal cord. Simultaneous immunofluorescence staining indicated that these neurons display corticotropin-releasing factor (CRF)-like immunoreactivity. Also, CRF-positive varicose fibers were detected in the intermediolateral column of the sacral cord. The results indicate the presence of CRF or a CRF-like peptide in a descending projection to the spinal cord that may be involved in regulating the micturition reflex.

Animals↗
PubMed1984

Dynorphin-immunoreactive neurons in the autonomic nervous system.

The distribution of dynorphin-like immunoreactivity in the autonomic nervous system of the rat and guinea-pig was investigated using an antiserum raised against dynorphin-(1-17). Dynorphin-like immunoreactivity was observed in fiber networks in the prevertebral sympathetic ganglia, in fibers in the enteric plexa , circular muscle layer and a few in the lamina muscularis of the mucosa of the gastrointestinal tract. After colchicine treatment dynorphin-immunoreactive cell bodies were observed both in the myenteric and submucous ganglia of the gut. The paravertebral ganglia contained occasional dynorphin-positive fibers and a few immunoreactive small intensely fluorescent cells. The distribution of the dynorphin-like immunoreactivity was compared to the distribution of enkephalin-like immunoreactivity, and it was found that in some areas there were similarities in the distribution patterns, although in other areas there were clear differences, indicating a non-identity of these two systems.

Adrenal Glands↗
PubMed1983

NADPH-diaphorase: a selective histochemical marker for the cholinergic neurons of the pontine reticular formation.

Choline acetyltransferase immunohistochemistry has identified a large group of cholinergic neurons in the pontine tegmentum. By combined immunohistochemical and enzyme histochemical studies this particular cholinergic cell group was found to contain an enzyme, NADPH-diaphorase, that can be visualized histochemically. Thus NADPH-diaphorase histochemistry provides a simple, reliable method to selectively stain the cholinergic neurons of the brainstem reticular formation. The resolution obtained by this novel histochemical technique is similar to that found with the Golgi stain, and it should therefore be of great value in morphological studies of this cholinergic cell group.

Animals↗
PubMed1983

Separate origins for the dynorphin and enkephalin immunoreactive fibers in the inferior mesenteric ganglion of the guinea pig.

By different denervation procedures the origin of dynorphin-(1-17) and enkephalin immunoreactive fibers in the guinea pig inferior mesenteric ganglion was investigated. It was found that the dynorphin-(1-17)-positive fibers reached the ganglion predominantly via the colonic nerves and to a lesser extent via the hypogastric and intermesenteric nerves whereas the enkephalin-positive fibers reached the ganglion via the lumbar splanchnic nerves. These findings show that the dynorphin-(1-17) and enkephalin systems are separate in this ganglion.

Animals↗
PubMed1983

NADPH-diaphorase: a selective histochemical marker for striatal neurons containing both somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivities.

Certain neurons in the brain are specifically and intensely stained by a histochemical method which demonstrates nicotinamide adenine dinucleotide phosphate NADPH-diaphorase activity. The cell types containing this enzyme in certain areas of the rat forebrain were examined by combining NADPH-diaphorase histochemistry with the indirect immunofluorescence technique. Neurons containing somatostatin- or avian pancreatic polypeptide (APP)-like immunoreactivities were found throughout the forebrain including the striatum and neocortex. These two neuropeptides were also found to coexist in many telencephalic neurons. After photography, the sections processed for immunohistochemistry were stained for NADPH-diaphorase activity by a histochemical method. It was found that within the striatum all of the neurons that were selectively stained by this technique also contained both somatostatin- and APP-like immunoreactivities. Also in the neocortex NADPH-diaphorase was found only in those neurons displaying somatostatin- or APP-like immunoreactivity. In other brain regions such as the nucleus laterodorsalis tegmenti, NADPH-diaphorase-containing cells did not contain these neuropeptides. The results indicate that NADPH-diaphorase histochemistry provides a simple, reliable, histochemical method to demonstrate those striatal neurons in which somatostatin- and APP-like immunoreactivities coexist. The selective occurrence of this enzyme within these neurons may provide a useful target for pharmacological studies of these neuropeptide-containing cells.

Animals↗
PubMed1983

Striatal neurons containing both somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivities and NADPH-diaphorase activity: a light and electron microscopic study.

Striatal neurons containing both somatostatin- and avian pancreatic polypeptide (APP)-like immunoreactivities have been shown to be selectively stained by the histochemical method for nicotinamide adenine dinucleotide phosphate (NADPH)-diaphorase activity. In the present study, we have utilized this histochemical technique to examine the morphology of these striatal neurons at the light and electron microscopic levels. Our results indicate that the striatal somatostatin/APP/NADPH-diaphorase neurons occur throughout the striatum and have long, aspiny dendrites, oval, invaginated nuclei with prominent nucleoli, and receive few axosomatic contacts. These cells appear to correspond to a population of medium-sized aspiny interneurons reported previously in Golgi and electron microscopic studies of the striatum.

Animals↗
PubMed1983

Hypothalamic gamma-aminobutyric acid neurons project to the neocortex.

Three groups of gamma-aminobutyric acid--containing neurons were found in the mammillary region of the posterior hypothalamus. The groups correspond to the tuberal, caudal, and postmammillary caudal magnocellular nuclei. Many cells in these nuclei were retrogradely labeled with fast blue after the injection of this fluorescent dye into the neocortex. Immunohistochemical experiments showed that these same neurons also contained the gamma-aminobutyric acid-synthesizing enzyme glutamate decarboxylase. These results provide morphological evidence for a gamma-aminobutyric acid pathway arising in magnocellular neurons of the posterior hypothalamus and innervating the neocortex.

Animals↗
PubMed1983

Histochemical demonstration of separate populations of somatostatin and cholinergic neurons in the rat striatum.

Striatal neurons containing acetylcholine and somatostatin were examined using a pharmacohistochemical procedure for acetylcholinesterase and NADPH-diaphorase histochemistry respectively. The use of these two histochemical procedures allowed both cholinergic and somatostatin cells to be visualized simultaneously in single sections of the striatum. The results indicate that somatostatin and acetylcholine are contained in separate populations of striatal neurons and illustrate the utility of simple histochemical procedures to visualize biochemically defined neurons.

Acetylcholine↗
PubMed1983

Demonstration of a unique population of neurons with NADPH-diaphorase histochemistry.

A simple enzyme histochemical technique is described that detects various distinct populations of neurons in the brain. These neurons contain an extremely high activity of an endogenous enzyme, NADPH-diaphorase, that can reduce the dye nitro blue tetrazolium to a bright blue reaction product. Some of the major groups of neurons detected by this technique occur scattered throughout the neocortex, in the striatum and in the laterodorsal tegmental nucleus. The soma, dendritic trees and fiber networks of the positive neurons are stained in their entirety. Thus this simple, reliable technique can be used to obtain a Golgi-like image of particular groups of neurons in various regions of the brain.

Animals↗
PubMed1983

Capsaicin-induced depletion of substance P-like immunoreactivity in guinea pig sympathetic ganglia.

The distribution of substance P immunoreactive nerve fibers in guinea pig sympathetic ganglia was studied in normal and capsaicin-treated animals. A marked depletion of substance P-like immunoreactivity was observed in both pre- and paravertebral ganglia after capsaicin treatment. In the inferior mesenteric and pelvic ganglia, however, intensely fluorescent fibers surrounding some of the principal ganglion cells remain after capsaicin treatment. Ligation experiments on the inferior mesenteric ganglion indicate that the capsaicin-insensitive substance P immunoreactive fibers in this ganglion are of lumbar splanchnic origin. Whether or not they represent capsaicin-resistant primary afferent neurons is not known. The enkephalin, vasoactive intestinal polypeptide, cholecystokinin and bombesin immunoreactive fiber networks in the inferior mesenteric ganglion were also studied, and no differences were observed between normal and capsaicin-treated animals.

Animals↗
PubMed1983

Immunohistochemical studies of the GABA system in the pancreas.

gamma-Amino butyric acid (GABA) is a major inhibitory neurotransmitter in the mammalian brain. In the present study the indirect immunofluorescence technique was employed to localize the GABA-synthesizing enzyme glutamate decarboxylase, and the GABA-metabolizing enzyme GABA-transaminase within the rat pancreas. Both enzymes were found to occur only in the beta-cells of the islets of Langerhans. The other endocrine cell types, the exocrine tissue and the nervous elements in the pancreas did not contain either enzyme. Animals treated with the beta-cell toxins streptozotocin or alloxan showed a loss of immunoreactive cells in the islets. The results provide morphological evidence of the coexistence of GABA and insulin in the beta-cells of the endocrine pancreas.

4-Aminobutyrate Transaminase↗
PubMed1982

Coexistence of cholecystokinin- and substance P-like peptides in neurons of the dorsal root ganglia of the rat.

Using the indirect immunohistochemical technique with antisera to cholecystokinin and to substance P, the spinal dorsal horn and dorsal root ganglia of normal and colchicine-treated rats were studied. In the spinal cord a similar distribution of substance P- and cholecystokinin-positive networks in the superficial layers of the dorsal horn was observed. In the dorsal root ganglia several cholecystokinin and substance P immunoreactive cell bodies were seen in colchicine-treated rats. After elution and restaining for substance P, of sections previously stained for cholecystokinin, it was found that all cholecystokinin-positive cells also contained substance P-like immunoreactivity and vice versa.

Animals↗
PubMed1982

GABA-transaminase in the basal ganglia: a pharmacohistochemical study.

A pharmacohistochemical procedure to demonstrate histochemically those cells with the ability to synthesize the GABA-metabolizing enzyme GABA-transaminase has been applied to determine the localization of this enzyme in the basal ganglia. In normal, pharmacologically unmanipulated animals, strong GABA-transaminase activity is present throughout the neuropil in many nuclei of the basal ganglia. The striatum, globus pallidus, entopeduncular nucleus, subthalamic nucleus and substantia nigra are all heavily stained. White matter such as the corpus callosum and internal capsule are unstained. Pretreatment of rats with the irreversible GABA-transaminase inhibitor ethanolamine-O-sulfate resulted in a marked reduction in the general neuropil staining. At a suitable post-injection survival time, cells which had synthesized new GABa-transaminase molecules could be detected. Small, positive neurons were present in the striatum and entopeduncular nucleus, while the globus pallidus, substantia nigra zona reticulata, and the ventral pallidal region contained many large, intensely GABA-transaminase-positive neurons. The results indicate that much of the GABA-transaminase in the basal ganglia is neuronal in origin. The relationship of GABA-transaminase to GABA neurons is discussed.

4-Aminobutyrate Transaminase↗