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Biomedical subjects

M Tohyama

Publications and source records attributed to M Tohyama.

At least 487 records · Page 27Linked to original sources
PubMed1985

Localization of chick retinal 24,000 dalton protein (visinin)-like immunoreactivity in the rat lower brain stem.

The distribution of visinin, a 24,000 dalton peptide, in the lower brain stem of the rat was examined by means of an indirect immunofluorescent method. Visinin-immunoreactive structures were found to be unevenly distributed only in the neuronal elements. The following neuronal systems were strongly labeled by the antiserum; the Purkinje cell system, mammillotegmental system, habenulointerpeduncular system, the second layer of the superior colliculus, ventral tegmental area, substantia nigra pars lateralis, area medial to the medial geniculate body, parabrachial area, dorsal and ventral nuclei of the lateral lemniscus, pontine reticular formation just medial to the trigeminal principal nucleus, superior olivary nucleus, solitarii nucleus, external layer of the inferior colliculus and spinal trigeminal nucleus. The densities of the labeled fibers in these areas paralleled those of the labeled cells. In addition, highly dense visinin-immunoreactive fiber plexuses were seen in the zona compacta of the substantia nigra, lateral portion of the interpeduncular nucleus, ventral tegmental nucleus of Gudden and vestibular nucleus.

Afferent Pathways↗
PubMed1985

Three dimensional analysis of retinal neuropeptides and amine in the chick.

Three dimensional analysis of retinal neuropeptides and monoamine-containing amacrine cells were performed on flat-mount preparations of the chick retina by using indirect immunofluorescence method. somatostatin (SOM), neurotensin (NT), leu-enkephalin (ENK), vasoactive intestinal polypeptide (VIP), substance P (SP), corticotropin releasing factor (CRF), avian pancreatic polypeptide (APP), glucagon (GLC), 5-hydroxytryptamine (5HT) and tyrosine hydroxylase (TH) were examined with specific antisera. To localize these substances in the amacrine cells, and to see in which layers their processes arborize, frozen sections were examined. There were four patterns of distribution. (1) Substances with more immunoreactive cells in the central than in the peripheral portions (SOM, NT, VIP, SP, GLC, 5HT), (2) Substances with more immunoreactive cells in the peripheral portion than in the central portion (APP), (3) Substances for which such cells were evenly distributed (TH), and (4) Substances with more immunoreactive cells in the inferior than in the superior portion (CRF). Subtypes were identified among the amacrine cells containing single peptides or monoamine.

Animals↗
PubMed1984

Growth of central substance P-containing neurons into superior cervical ganglia transplanted in the spinal cord of adult rats.

Superior cervical ganglia (SCG) contain substance P-like immunoreactive (SP-IR) fibers but not SP-IR neurons. In the present study, SCG were excised from adult rats and transplanted into the same animal's spinal thoracic cord (Th10). One or two weeks after the operation, SP-IR fibers from the host spinal cord or a higher level had grown and entered the transplanted SCG where they formed direct contacts with SCG neurons. However, these phenomena could not be observed when dorsal root ganglia (L4), which contained numerous SP-IR cells, were transplanted into their own spinal cord (Th10). This suggests that the SP-IR neuron system in the adult is able to grow "new axons' to the grafted tissue to form a "new SP-IR' neuronal circuit when the grafted tissue has lost its own SP-IR input.

Animals↗
PubMed1984

Origins of histamine-containing fibers in the cerebral cortex of rats studied by immunohistochemistry with histidine decarboxylase as a marker and transection.

The origins of histamine-containing fibers in the cerebral cortex were examined by means of the retrograde tracer technique of horseradish peroxidase (HRP)-immunohistochemistry with histidine decarboxylase (HDC) as a marker for the histamine neuron system. Total transection of the brain rostral to the posterior hypothalamus resulted in disappearance of HDC-like immunoreactive (HDCI) fibers in the cerebral cortex, but total transection caudal to the posterior hypothalamus did not decrease the number of HDCI fibers in the cortex, suggesting that HDCI fibers in the cerebral cortex originate in the posterior hypothalamus. The projection of HDCI neurons from the posterior hypothalamus to the cerebral cortex seemed to be bilateral because hemi-transection of the brain rostral to the posterior hypothalamus resulted in a bilateral decrease of HDCI fibers in the cerebral cortex with ipsilateral predominance. After injection of HRP into the cerebral cortex, numerous cells containing both HRP granules and HDCI structures were found bilaterally in the tuberal, caudal and postmamillary magnocellular nuclei, with ipsilateral predominance. These findings indicate that HDCI cells in the above nuclei give rise to axons extending bilaterally to the cerebral cortex.

Animals↗
PubMed1984

Dual innervation of substance P-containing neuron system in the wall of the cerebral arteries.

The present study has shown the presence of substance P-like immunoreactive (SPI) fiber plexuses both in the carotid and vertebrobasilar systems in the Mongolian gerbil, suggesting that the origins of SPI fibers in these two systems differ. The present study further demonstrated in the guinea pig, using experimental manipulations, the dual origin of SPI fibers in the cerebral arteries; one from the trigeminal ganglion (TG) that mainly innervates the carotid system, and the other that separates from the TG and mainly innervates the vertebrobasilar system.

Animals↗
PubMed1984

Fine structure of histaminergic neurons in the caudal magnocellular nucleus of the rat as demonstrated by immunocytochemistry using histidine decarboxylase as a marker.

The morphology of histamine-containing neurons in the caudal magnocellular nucleus was light and electron microscopically examined by means of peroxidase-antiperoxidase (PAP) immunocytochemistry with histidine decarboxylase (HDC) as a marker. HDC-like immunoreactive (HDCI) neurons had large (25-30 microns in diameter) perikarya from which two to four primary dendrites arose. The perikarya had a nearly round nucleus and well-developed Golgi apparatus in addition to a large number of mitochondria and rough endoplasmic reticulum. Immunoreactive endproducts were found diffusely throughout the perikarya, dendrites, and axons. HDCI neurons made synaptic contact with nonreactive axon terminals on the perikarya and dendrites. In addition, the HDCI neurons very frequently formed puncta adherentia with neuronal elements, either HDCI or nonreactive, or glial cells. Most of the HDCI axon terminals serially observed under electron microscopy did not exhibit typical synaptic contact in the caudal magnocellular nucleus. These findings suggest the nonsynaptic release of histamine in the caudal magnocellular nucleus.

Animals↗
PubMed1984

Neuropeptides and gamma-aminobutyric acid in the vestibular nuclei of the rat: an immunohistochemical analysis. I. Distribution.

The distribution of substance P, Leu-enkephalin and gamma-aminobutyric acid (GABA) containing structures in the rat vestibular nuclei were investigated by means of an indirect immunofluorescent method using specific antisera to substance P, Leu-enkephalin and glutamic acid decarboxylase (GAD), respectively. Numerous positive neurons and fibers containing these three substances were found in the medial vestibular nucleus. Most of them were situated in the caudal part of the nucleus and those in the rostral part were concentrated dorsally. In the descending vestibular nucleus, a large number of substance P, Leu-enkephalin and GAD containing neurons were evenly distributed among longitudinally directing fiber bundles. A number of positive fibers with these substances were also observed. The lateral vestibular nucleus contained numerous coarse GAD-immunoreactive fibers surrounding Deiters' neurons, while substance P-immunoreactive and Leu-enkephalin-immunoreactive fibers were rather poorly distributed in this nucleus as well as in the superior vestibular nucleus.

Animals↗
PubMed1984

Immunoreactive avian pancreatic polypeptide in the chicken retina: overall distribution.

The distribution of avian pancreatic polypeptide (APP)-like immunoreactivity (APP-IR) in the chicken retina was investigated by means of immunohistochemistry. The observation from frozen sections showed that APP-IR is localized in the stratified amacrine cells of the first sublayer. Examination of whole-mounts revealed that APP-IR fibers from a dense fiber plexus at the peripheral margin area and peripheral portion of the retina where they run circumferentially. APP-IR neurons are located in the peripheral portion. From the three-dimensional profiles, APP-IR amacrine cells could be divided into two types.

Animals↗
PubMed1984

Bilateral alpha-melanocyte stimulating hormonergic fiber system from zona incerta to cerebral cortex: combined retrograde axonal transport and immunohistochemical study.

We employed a highly sensitive combination method of retrograde tracing and immunohistochemistry to identify an alpha-melanocyte-stimulating hormone (alpha-MSH)-containing fiber pathway from zona incerta to cerebral cortex. Biotin-horseradish peroxidase injected into the parietal cortex of the rat labeled a number of neurons in the zona incerta bilaterally, and simultaneous staining with an alpha-MSH antiserum revealed that a part of these neurons are alpha-MSHergic.

Animals↗
PubMed1984

Evidence for an alpha-melanocyte stimulating hormonergic hippocampal commissural connection in the rat, revealed by a double-labeling technique.

A new double-labeling method combining immunocytochemistry and a retrograde tracer technique using biotin-conjugated horseradish peroxidase (B-HRP) was developed. Retrogradely accumulated B-HRP was visualized in the soma by incubation with avidin-conjugated fluorescein isothiocyanate (FITC-green fluorescein) solution. Texas red (red fluorescein)-conjugated goat anti-rabbit IgG was used for simultaneous demonstration of the antigen. Using this method, the present study reports a newly demonstrated commissural hippocampal alpha-melanocyte stimulating hormonergic neuron system in the rat.

Animals↗
PubMed1984

Two distinct strio-nigral substance P pathways in the rat: an experimental immunohistochemical study.

Re-examination of the strio-nigral substance P (SP) tract by means of an experimental immunohistochemical method in the rats demonstrated the presence of two distinct pathways from the nucleus caudatus putamen (CP) to the substantia nigra (SN). Destruction of the posterior portion of the CP resulted in the disappearance of SP-positive fibers in the SN pars lateralis but not in the SN pars compacta or reticulata. On the other hand, destruction of the ventrolateral portion of the anterior portion of the CP caused the disappearance of SP-positive fibers in the SN pars compacta and pars reticulata but not in the SN pars lateralis. In addition, destruction of the dorsal portion of the anterior portion of the CP, where 3-6 cell islets of SP-positive cells are located, failed to decrease SP-positive fibers in any of the subdivisions of the SN. These findings strongly suggest that SP-positive neurons in the posterior portion of the CP project to the SN pars lateralis (posterior strio-nigral SP tract), SP-positive cells in the lateroventral part of the anterior portion of the CP extend to the SN pars compacta and pars reticulata, but SP-positive cells in the dorsal part of the anterior portion of the CP do not innervate the SN.

Animals↗
PubMed1984

Fine structural studies of cholecystokinin-8-like immunoreactive neurons and axon terminals in the nucleus of tractus solitarius of the rat.

Cholecystokinin (CCK)-8-like immunoreactive structures in the nucleus of tractus solitarius (NTS) were studied by using the peroxidase-antiperoxidase (PAP) immunohistochemical method. Immunoreactivity was localized in cell bodies and nerve fibers. The perikarya were oval or fusiform (average length 13 micron) and were mostly located in the dorsal half of the medial subnucleus of the NTS at the level of the area postrema (AP). One to three straight immunoreactive dendritelike processes emerged from the perikarya. Neurons that had first been identified under light microscopy were also studied by electron microscopy. Each neuron had a moderate amount of cytoplasm and an oval or elongated nucleus that was eccentrically located in the soma. A few synaptic inputs were found on the CCK immunoreactive perikarya, while a moderate number were seen on both proximal and distal dendrites. These neurons received both asymmetrical and symmetrical synaptic inputs. The immunoreactive dendrites were most frequently in asymmetrical synaptic contact with nonreactive boutons (max. 2.7 micron in diameter) containing fairly densely packed, small round vesicles. CCK immunoreactive boutons located in the NTS at the level of the AP were analyzed using electron microscopy; these boutons formed asymmetrical synaptic contact with other neuronal elements. Their postsynaptic targets were immunoreactive and nonreactive perikarya and dendrites. These data suggest that CCK-containing afferents might affect the neurotransmission of heterogenous types of solitary neurons.

Animals↗
PubMed1984

Immunoelectron-microscopic study on the fine structure of substance-P-containing fibers in the taste buds of the rat.

The fine structure of substance-P-like immunoreactive [SPI] fibers in the taste buds of the circumvallate papillae of the rat tongue was investigated by means of electron microscopy using the unlabeled antibody-enzyme method. Outside the epithelium, SPI and non-SPI fibers are surrounded by the cytoplasm of Schwann cells. When the SPI fibers enter the epithelium, they immediately lose this cytoplasmic sheath and begin to traverse the taste buds. Though passing through the taste buds, no profiles suggesting clear synaptic contact between SPI fibers and underlying cells are identified. SPI terminals are filled with small synaptic vesicles and contain a few mitochondria. No SPI-positive structures are found in nerve endings that make synaptic contact with type III cells, the gustatory receptor cells.

Animals↗
PubMed1984

Cholecystokinin-8-like immunoreactivity in the pre- and post-central gyri of the human cerebral cortex.

Cellular localization of cholecystokinin-8-like immunoreactive (CCK-IR) structures in the pre- and post-central gyri of the human cerebral cortex was examined by indirect immunofluorescence. CCK-IR was localized mostly in perikarya of non-pyramidal cells such as multipolar, bitufted and bipolar cells, and to a lesser extent in medium and small pyramidal cells. CCK-IR fibers were also observed in these gyri, predominantly in layers I and III.

Cerebral Cortex↗
PubMed1984

Corticotropin-releasing factor in the amacrine cells of the chicken retina.

The distribution of ovine corticotropin-releasing factor (CRF)-like immunoreactivity (CRFI) in the chicken retina was investigated by means of immunohistochemistry. The observations from frozen sections show that CRFI is localized in the stratified amacrine cells of the fourth sublayer . Whole-mount preparations revealed that these amacrine cells are moderately concentrated in the inferior part of the retina.

Animals↗
PubMed1984

Immunocytochemical localizations of cytosolic and mitochondrial glutamic oxaloacetic transaminase isozymes in rat brain.

The localizations of cytosolic (s-) and mitochondrial (m-) glutamic oxaloacetic transaminase (GOT) were examined by immunocytochemical methods using specific antibodies. Staining of s-GOT-like immunoreactivity was seen in periglomerular cells of the olfactory bulb, and basket, stellate cells of the cerebellum, and second layer cells of the neocortex. On the other hand, m-GOT-like immunoreactivity was found in mitral cells and glomerular regions of the olfactory bulb and deep Golgi cells of the cerebellum. These different distributions of s- and m-GOT isozymes suggest that these isozymes are available as markers of glutamergic or aspartergic neurons.

Animals↗