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M Tohyama

Publications and source records attributed to M Tohyama.

At least 505 records · Page 28Linked to original sources
PubMed1984

The distribution and projection of gamma-melanocyte stimulating hormone in the rat brain: an immunohistochemical analysis.

The distribution and projection of immunoreactive gamma-melanocyte-stimulating hormone (gamma-MSHI) in the rat brain was examined by indirect immunofluorescence using an antiserum against synthetic rat gamma-MSH. The present study confirmed the presence of gamma-MSHI neurons in the arcuate nucleus and further demonstrated that the n. commissuralis is a new gamma-MSHI neurons-containing site. We also found a gamma-MSHI fiber network in the hypothalamus, thalamus, amygdala, central gray matter of the midbrain and upper pons, and further demonstrated a much more extensive distribution of these fibers particularly in the medulla oblongata, an area previously thought not to contain gamma-MSHI structures. The present observation on the normal distribution of gamma-MSHI suggested the existence of two different systems: one is the arcuatofugal gamma-MSH system and the other n. commissuralis gamma-MSH system. Using experimental manipulations, we clearly established that gamma-MSHI fibers in the forebrain, diencephalon, midbrain and upper pons originate from gamma-MSHI neurons in the arcuate nucleus and those in the medulla oblongata from the n. commissuralis .

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PubMed1984

Distribution of the histaminergic neuron system in the central nervous system of rats; a fluorescent immunohistochemical analysis with histidine decarboxylase as a marker.

The distribution of histidine decarboxylase-like immunoreactivity (HDCI) in the rat central nervous system was studied by the indirect immunofluorescence technique. HDCI cell bodies were concentrated in the posterior hypothalamic area, such as in the tuberal magnocellular nucleus, caudal magnocellular nucleus, posterior hypothalamic nucleus and lateral hypothalamus just lateral to the fasciculus mammillothalamicus at the level of the posterior hypothalamic nucleus. Extensive networks of HDCI fibers of various densities were found in many areas of the brain; they were particularly dense in the hypothalamus but were also found in the following areas: rostrally in the cerebral cortex, olfactory nuclei, medial amygdaloid nucleus, n. tractus diagonalis, and bed nucleus of the stria terminalis, and caudally in the central gray matter of the midbrain and pons, auditory system, n. vestibularis medialis, n. originis nervi facialis, n. parabrachialis, n. commissuralis, n. tractus solitarii, and n. raphe dorsalis.

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PubMed1984

Experimental immunohistochemical studies on the substance P neuron system in the lateral habenular nucleus of the rat: distribution and origins.

We examined the distribution and afferent projections of substance P-like immunoreactive (SPI) fibers in the lateral habenular nucleus of the rats by using the indirect immunofluorescence method. On the basis of the distribution, a dense plexus of SPI fibers in the lateral habenular nucleus (LHb) could be divided into two parts: medial (mLHb) and lateral (lLHb). The present study demonstrates that SPI fibers in the lLHb originate from SPI cells in the rostral entopeduncular nucleus (rEP) and the adjacent area, while those in the mLHb originate from SPI cells in the medial habenular nucleus. Moreover, we showed that the axons from SPI cells in the rEP reached the lLHB via the "pallidohabenular tract."

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PubMed1984

Three-dimensional distribution of vasoactive intestinal polypeptide-containing structures in the rat stomach and their origins using whole mount tissue.

The three-dimensional distribution of vasoactive intestinal polypeptide (VIP)-like immunoreactive (VIPLI) structures in rat stomach and their origins were investigated using the indirect immunofluorescence method in whole mounted tissue. The present study demonstrates a very dense VIPLI fiber meshwork in the circular muscle layer, longitudinal muscle layer and myenteric plexus. In the muscle layers VIPLI immunoreactive fibers run parallel to the muscle. VIPLI fibers are distributed evenly throughout the entire stomach. We have also shown by experimental manipulations that the fibers in the stomach originate from VIPLI neurons in the myenteric plexus.

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PubMed1984

A simple method for the separation of retinal sublayers from the entire retina with special reference to application for cell culture.

We developed a simple method for the separation of rat retinal sublayers. The rat retina was carefully removed from the sclera and treated in trypsin solution. After this treatment, the retinal sublayers could be easily separated by using Millipore filter paper into an outer nuclear layer, an inner nuclear layer, an inner plexiform layer, and a ganglion cell layer + nerve fiber layer. The viable cells of each of the sublayers could be cultured on a poly-L-lysine coated chamber for at least several weeks in Eagle's minimum essential medium supplemented with calf serum and glucose.

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PubMed1984

Ontogeny of neuropeptides in the nucleus ventromedialis hypothalami of the rat: an immunohistochemical analysis.

The ontogeny of leucine-enkephalin (ENK)-, cholecystokinin-8 (CCK)-, substance P (SP)- and neurotensin (NT)-like immunoreactive structures were examined in the nucleus ventromedialis hypothalami (vm) of the rat by means of an indirect immunofluorescence method. ENK- (ENKI), SP- (SPI) and CCK-like immunoreactive (CCKI) structures in the vm exhibited very similar ontogenetic developments, though no CCKI cells were detected. ENKI fibers as well as SPI fibers and neurons first appeared at gestational day 21, ENKI neurons at postnatal day 2, and CCKI fibers at postnatal day 1. These structures subsequently increased in number. The maximum content was reached at postnatal day 21 and was observed even in the adult rats (postnatal day 30). On the other hand, NTI fibers first appeared at postnatal day 1; they decreased in number and no or only a few NTI fibers were seen in the adult rats. No NTI cells were seen in the vm.

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PubMed1984

Ontogeny of substance P-containing structures in the ocular tissue of the rat: an immunohistochemical analysis.

The ontogeny of the substance P-like immunoreactivity (SPI) containing system in the ocular tissue of the rat was examined by means of the indirect immunofluorescence method. SPI-containing amacrine cells first appeared at postnatal day 4 and displaced SPI-containing amacrine cells at postnatal day 5. After this time, they developed markedly reaching their maximum content and distribution at postnatal day 14. On the other hand, SPI-containing cells in the trigeminal ganglion were first seen at gestational day 17 and reached their maximum content at birth. SPI-containing fibers in the cornea and uvea were first observed at gestational days 17-19. The SPI-containing fibers in the iris reached their maximum content at birth, while those in the cornea, choroid and ciliary body were fully developed at postnatal day 3. In the adult rats, numerous SPI structures were still seen in the ocular tissue, retina, cornea and uvea. These findings suggest that SPI might play some role in the developing ocular tissue in addition to its neurotransmitter or neuromodulator role in the adult, because SPI structures appear in the retina before establishment of synaptogenesis and in the cornea and uvea during the fetal stage.

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PubMed1984

Distribution of six neuropeptides in the nucleus tractus solitarii of the rat: an immunohistochemical analysis.

Distribution of substance P-, [Leu]enkephalin-, cholecystokinin-8-, neurotensin-, avian pancreatic polypeptide- and gamma-melanocyte stimulating hormone-like immunoreactive structures were investigated in the nucleus tractus solitarii of the rat by means of the indirect immunofluorescence method. The density of the immunoreactive structures varied markedly according to neuropeptides or subnuclei, with the medial and commissural nuclei containing the highest density. This suggests that the peptides examined play a role in cardiovascular function. However, as seen in the substance P- and [Leu]enkephalin-like immunoreactive structures, these peptides were widely distributed in the nucleus tractus solitarii in addition to the commissural and medial nuclei; a high density of immunoreactive fibers in the ventral, dorsolateral and intermediate subnuclei. In addition to the immunoreactive fiber plexus, a group of immunoreactive cells was also identified in the subnuclei mentioned above. These findings strongly suggest that substance P- and [Leu]enkephalin-like immunoreactive structures are involved not only in cardiovascular function but also in other functions such as respiration, at least in the rat. Finally, the present study demonstrated that the area postrema, particularly its lateral portion, contains various neuropeptide-like structures, both neurons and fibers, substance P-, [Leu]enkephalin-, cholecystokinin-8- and neurotensin-like immunoreactive neurons and fibers, and avian pancreatic polypeptide- and gamma-melanocyte stimulating hormone-like immunoreactive fibers.

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PubMed1984

Immunohistochemical evidence for the coexistence of histidine decarboxylase-like and glutamate decarboxylase-like immunoreactivities in nerve cells of the magnocellular nucleus of the posterior hypothalamus of rats.

Immunohistochemical staining of alternate consecutive sections revealed numerous histidine decarboxylase (L-histidine carboxy-lyase, EC 4.1.1.22)-like immunoreactive neurons that also contained glutamate decarboxylase (L-glutamate 1-carboxy-lyase, EC 4.1.1.15)-like immunoreactive structures in the tuberal magnocellular nucleus, the caudal magnocellular nucleus, and the postmammillary caudal magnocellular nucleus of the posterior hypothalamus of rats. Furthermore, in immunohistochemical double-staining procedures, almost all neurons in the magnocellular nuclei had both histidine decarboxylase-like and glutamate decarboxylase-like immunoreactivities. These results suggest the coexistence of histamine and gamma-aminobutyric acid in single neurons in these nuclei.

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PubMed1984

Origins and three-dimensional distribution of substance P-containing structures on the rat stomach using whole-mount tissue.

The origin and three-dimensional distribution of substance P-immunoreactive structures in the rat stomach were investigated by means of the indirect immunofluorescence method using whole-mount tissue. The present study demonstrated that the myenteric plexus contained a very high concentration of substance P-immunoreactive fibers. It also contained cells that were moderately concentrated in the greater curvature, with those closer to the lesser curvature decreasing in number. In addition, a number of fibers ran parallel to the muscles in the circular and longitudinal muscle layers; these were distributed evenly throughout the entire stomach. We further found that most of the fibers located in the myenteric plexus originated from the greater splanchnic nerve from T5 to L2, but that some originated from intrinsic substance P-immunoreactive cells in the myenteric plexus. The fibers in the circular and longitudinal muscle layers originated from the cells in the myenteric plexus.

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PubMed1984

Overall distribution of substance P nerves in the rat cornea and their three-dimensional profiles.

The overall distribution of substance P-like immunoreactive (SPI) fibers, examined by using whole-mounts of the rat cornea, was investigated by means of indirect immunofluorescence. SPI fibers entered the cornea from two levels; one from the middle layer of the sclera and the other from the episclera. From the sclera, a thick SPI fiber trunk, extending to the central part, subdivided into smaller SPI fiber bundles and approached the epithelium. The SPI fiber bundles from the episclera were smaller than those from the sclera. However, both fiber bundles formed a dense fiber network in the uppermost part of the stroma. This fiber plexus dissociated into SPI fibers extending to the superficial part of the epithelium where they formed an abundant arborization of fine SPI fibers. The results suggest that these fibers originate from SPI neurons in the trigeminal ganglion.

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PubMed1984

Distribution, origin, and fine structures of cholecystokinin-8-like immunoreactive terminals in the nucleus ventromedialis hypothalami of the rat.

The distribution, origin, and fine structures of cholecystokinin-8-like immunoreactive ( CCKI ) fibers in the nucleus ventromedialis hypothalami (vm) of the rat were examined using immunohistochemistry. CCKI fibers were moderately concentrated in the ventrolateral part of the vm, decreasing in number dorsomedially. However, no CCKI cells were seen in the vm even in colchicine-treated rats. In addition, the destruction of the lateral part of the nucleus parabrachialis dorsalis (pbd) where numerous CCKI cells were seen resulted in a marked decrease in CCKI fibers in the vm on the operated side. Electron microscopic observations revealed that CCKI terminals make synaptic contact with soma, spine, and the proximal segment of the dendrite. The neurons making synaptic contact with the CCKI fibers had moderately electron-lucent cytoplasm. These findings suggest that the CCKI fibers in the vm originate from CCKI cells in the lateral part of the pbd and directly influence the vm neurons.

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PubMed1984

Electron microscopic identification of histidine decarboxylase-containing endocrine cells of the rat gastric mucosa. An immunohistochemical analysis.

The localization of histidine decarboxylase-like immunoreactive structures in the mucosal cells of the rat stomach was studied by the peroxidase-antiperoxidase method. At the light microscopic level, histidine decarboxylase-like immunoreactivity-containing cells were concentrated in the basal part of the oxyntic region, whereas in other areas no immunoreactive cells were seen. Ultrastructural study showed that reaction end products were diffusely distributed within the cytoplasm of the enterochromaffinlike cells but other cell types such as A cells, G cells, and enterochromaffin cells were not labeled. These findings suggest that enterochromaffinlike cells synthesize histamine.

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PubMed1983

Immunoreactive glucagon in the vascular walls of the rat.

We detected immunohistochemically immunoreactive glucagon (IRG) in the smooth muscle of blood vessels and the myoepithelial cell of sweat glands of rats using two antisera against pancreatic glucagon; OAL-123 and 30K. The content of IRG in the blood vessels was found to be 320-1, 270 pg per g wet tissue weight. Filtration of the extracted IRG through a Bio Gel P-30 column yielded a single peak of IRG at 3,500 daltons, the same elution volume of pancreatic glucagon. These findings suggest that the blood vessels of the rats is one of the extrapancreatic sources of IRG in plasma, although physiological role of the IRG is not known.

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PubMed1983

Evidence for the presence of a histaminergic neuron system in the rat brain: an immunohistochemical analysis.

Histamine-containing cells in rats were identified by indirect immunofluorescent histochemistry using an antibody raised against histidine decarboxylase (HDC), the enzyme forming histamine, which was purified from fetal rat liver. HDC-like immunoreactive (HDCI) structures could be detected in the brain as well as in peritoneal mast cells and basal-granulated cells in deep crypts of the gastric mucosa of rats. Numerous HDCI neurons were found in the posterior hypothalamic area and HDCI nerve fibers with a varicose appearance of fluorescence were widely distributed in various regions of the brain.

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PubMed1983

Leucine-enkephalin-containing neuron system in the facial nucleus of the rat with special reference to its fine structure.

The light and electron microscopic localization of leucine-enkephalin-containing terminals in the facial nucleus of the rat were investigated by means of the peroxidase-antiperoxidase (PAP) immunocytochemical technique. By light microscopy, leucine-enkephalin-like immunoreactive (LEI) terminals were unevenly distributed in the facial nucleus. The greatest accumulation of the terminals was seen in the medial part of the nucleus. Electron microscopic examination of LEI-terminals in the medial part of the nucleus revealed that the predominant type of synaptic contacts of LEI-terminals in this area were axo-dendritic contacts (about 75%). These dendrites which made synapses with LEI-terminals were relatively large and rich in cytoplasmic organella, suggesting that they belonged to the proximal segment of the dendrite. A small number of LEI-terminals was found to make synaptic contact with neuronal perikarya (5%). These perikarya were very large and had nuclei with less chromatin particles. These findings suggest that LEI-terminals make contact with neurons which exist in the facial nucleus. The rest of the LEI-terminals (20%) were in apposition to the non-labelled axon terminals which contain small, clear and round vesicles.

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