Biomedical subjects

M Tohyama

Publications and source records attributed to M Tohyama.

At least 451 records · Page 25Linked to original sources

PubMed1985

Distribution of neuropeptide Y in the forebrain and diencephalon: an immunohistochemical analysis.

The distribution of neuropeptide Y (NPY)-like immunoreactive (NPYI) structures in the rat forebrain and upper brainstem was examined by means of indirect immunofluorescence and peroxidase-antiperoxidase methods. The present study has demonstrated a much wider and more abundant distribution of NPYI structures in the forebrain and diencephalon than earlier studies in which antisera against avian pancreatic polypeptide or bovine pancreatic polypeptide were used, suggesting that NPY is involved in a variety of brain functions.

Animals↗

PubMed1985

Ontogeny of substance P-like immunoreactive fibers in the taste buds and their surrounding epithelium of the circumvallate papillae of the rat. II. Electron microscopic analysis.

We studied the ontogeny of the fine structure of substance P-like immunoreactive (SPI) fibers in the extragemmal epithelium and taste buds of the circumvallate papillae in the rat tongue by electron microscopy and by the unlabeled antibody-enzyme method. SPI fibers in the lamina propria first appeared at gestational day 19, and those in the extragemmal epithelium and in the taste buds at day 21. These fibers did not form synaptic contact with underlying cells. In addition, the occurrence of nonimmunoreactive fibers in these areas preceded that of SPI fibers. Our findings suggest that SPI fibers are not primarilly involved in the differentiation of the extragemmal epithelium and taste bud cells.

Animals↗

PubMed1985

Distribution and fine structure of neuronal elements containing glutamate decarboxylase in the rat cochlear nucleus.

Distribution and fine structure of gamma-aminobutyric acid (GABA)-containing structures were examined in the rat cochlear nuclear complex by means of immunohistochemistry using glutamate decarboxylase (GAD) as a marker. GAD-like immunoreactive (GADI) terminals were diffusely distributed in the dorsal cochlear nucleus, while in the ventral cochlear nucleus numerous immunoreactive fibers were situated around the cell bodies. These light-microscopic observations were confirmed by electron microscopy. Evidence suggesting that many of GADI boutons in the cochlear nucleus are of intrinsic origin was also shown.

4-Aminobutyrate Transaminase↗

PubMed1985

So-called interplexiform cells immunoreactive to tyrosine hydroxylase or somatostatin in rat retina.

The morphology of so-called interplexiform (IP) cells immunoreactive to tyrosine hydroxylase (TH) or somatostatin (SOM) in the rat retina was described in comparison with those in the carp retina. In frozen cross-sections of the rat retina, many processes of TH-like immunoreactive cells were found to extend toward the outer plexiform layer (OPL), forming a thin layer of network fibers. A few of them further extended into the photoreceptor cell layer; such fibers were never found in the carp retina. Some processes of SOM-like immunoreactive cells in the rat retina were found to travel across the inner nuclear layer and appeared to poorly develop a network at the OPL. In the carp retina, on the other hand, only one exceptional cross-section contained such an ascending process.

Animals↗

PubMed1985

Light and electron microscopic studies of calcitonin gene-related peptide-like immunoreactive neurons and axon terminals of the nucleus of the tractus solitarius of the rat.

This study was an examination of the ultrastructural characteristic features of calcitonin gene-related peptide (CGRP)-like immunoreactive neurons and their axon terminals in the nucleus of the tractus solitarius of the rat. Some axon terminals were identified as receiving synaptic inputs from non-immunoreactive axon terminals. This may suggest that part, if not all, CGRP containing afferents are affected presynaptically by other afferents.

Animals↗

PubMed1985

The calcitonin gene-related peptide-containing fiber projection from the hypothalamus to the lateral septal area including its fine structures.

The afferent source of calcitonin gene-related peptide-like immunoreactive (CGRPI) fibers in the lateral septal area of the rat was sought by using indirect immunofluorescence technique. These fibers decreased markedly on the operated side after the destruction of the area between the anterior hypothalamic nucleus and the lateral hypothalamus where there were a number of CGRPI cells. We also examined the fine structure of CGRPI fibers in the lateral septal area. Many CGRPI fibers forming axosomatic synapses were identified. These facts strongly suggest that CGRPI cells in the area between the anterior hypothalamic nucleus and the lateral hypothalamus project ipsilaterally to the lateral septal area and directly influence the soma there.

Animals↗

PubMed1985

Calcitonin gene-related peptide projection from the ventromedial thalamic nucleus to the insular cortex: a combined retrograde transport and immunocytochemical study.

We employed a highly sensitive combination method of retrograde tracing and immunohistochemistry to identify calcitonin gene-related peptide (CGRP)-containing fiber pathways in the rat from the ventrolateral part of the ventrolateral thalamic nucleus (vl-vl) and the caudal continuation to the insular cortex. Biotin-wheat germ agglutinin (B-WGA) injected into the insular cortex labeled numerous neurons in the vl-vl and the caudal continuation ipsilaterally; simultaneous staining with CGRP antiserum revealed that some of these neurons are CGRP positive.

Animals↗

PubMed1985

Effect of calcitonin gene-related peptide on contraction of striated muscle in the mouse.

We have found ultrastructurally calcitonin gene-related peptide-like immunoreactivity in the axon terminal within the synaptic trough of neuromuscular junction of the mouse. We determined, using pharmacological means, with a phrenic nerve-diaphragm preparation, that this peptide enhances muscle contraction during stimulation of the nerve fibers or direct stimulation of the muscle. This effect is probably brought about via the receptor for this peptide not the acetylcholine receptor.

Animals↗

PubMed1985

Peptidergic and aminergic innervation of the facial nucleus of the rat with special reference to ontogenetic development.

The distribution and ontogenetic development of several neuropeptides such as enkephalin, substance P, somatostatin, neuropeptide Y, and of monoamines such as serotonin and catecholamines in the facial nucleus of the rat were investigated with immunocytochemistry. The neuropeptides were concentrated in certain subnuclei. Enkephalin-immunoreactive fibers were distributed in the medial and dorsal subnuclei, substance P in the intermediate and dorsal subnuclei, somatostatin in the intermediate subnucleus, and neuropeptide Y in the dorsal subnucleus. The amines were distributed evenly throughout the nucleus. These distribution patterns suggest that peptidergic fibers are closely related to the functions of different subnuclei, while fibers containing monoamines are more basic--not specific to individual muscles. Few of these fibers were observed in the prenatal stage of the rat, but they increased markedly in number during the first postnatal week, and had established their innervation pattern by the tenth postnatal day, which coincides with the establishment of nerve-muscle innervation. The present study further showed that fibers containing serotonin are supplied mainly from the raphe nucleus, that catecholamine fibers are from neurons containing catecholamine surrounding the facial nucleus, and that fibers containing neuropeptide Y are from the lateral part of the caudal medullary reticular formation. These findings suggest that catecholamine and neuropeptide Y are not both present in the single neurons projecting to the facial nucleus.

Animals↗

PubMed1985

Immunohistochemical analysis of the cross-reaction of anti-rat histidine decarboxylase antibody with guinea-pig DOPA decarboxylase.

L-Histidine decarboxylase [L-histidine carboxylyase, HDC, EC 4.1.1.22] is an enzyme distinct from L-DOPA decarboxylase [L-aromatic amino acid carboxylyase, DDC, EC 4.1.1.28]: the two decarboxylases from fetal rat liver were completely separated from each other by DEAE-cellulose column chromatography and by affinity chromatography with L-carnosine as a ligand. The antibody raised against this HDC inhibited the HDC's from rat and guinea-pig brains very strongly, but their DDCs very weakly. However, in immunofluorescent histochemical studies, the antibody cross-reacted with DDC-like immunoreactive structures, such as chromaffin cells of the adrenal medulla, the raphe nucleus, the substantia nigra, and the locus coeruleus of the brain of guinea-pigs, but not of rats, suggesting that these two decarboxylases share some antigenic structures.

Adrenal Medulla↗

PubMed1985

The descending alpha-MSHergic (alpha-melanocyte-stimulating hormone-ergic) projections from the zona incerta and lateral hypothalamic area to the inferior colliculus and spinal cord in the rat.

Neuronal pathways containing alpha-melanocyte-stimulating hormone (alpha-MSH) extending from the zona incerta and lateral hypothalamic area to the inferior colliculus and spinal cord were analyzed using both immunohistochemical localization and a retrograde tracer. Biotinized horseradish peroxidase injected into the inferior colliculus or the thoracic cord of the rat labeled a number of neurons in the zona incerta and lateral hypothalamic area. Simultaneous immunostaining of the same sections with alpha-MSH antiserum showed that some of these neurons are alpha-MSHergic.

Animals↗

PubMed1985

Ultrastructural evidence of direct synaptic contact of catecholamine terminals with oxytocin-containing neurons in the parvocellular portion of the rat hypothalamic paraventricular nucleus.

Ultrastructural evidence of the direct interaction between catecholamine (CA) terminals and oxytocin (OX)-containing neurons in the parvocellular portion of the rat hypothalamic paraventricular nucleus was demonstrated using immunohistochemistry combined with false transmitter (5-hydroxydopamine, 5-OHDA) histochemistry. At the parvocellular portion, 5-OHDA labelled CA terminals make synaptic contact with proximal dendrites or somas of OX-positive cells, suggesting that the ascending CA system monosynaptically regulates the extrahypothalamic OX system.

Animals↗

PubMed1985

Distribution of neuropeptide Y in the lower brainstem: an immunohistochemical analysis.

The distribution of neuropeptide Y (NPY)-like immunoreactive (NPYI) structures in the rat lower brainstem was examined by means of indirect immunofluorescence or peroxidase-antiperoxidase methods. In addition to the well known immunoreactive NPYI containing cell groups, the present study demonstrated a much wider distribution of immunoreactive NPYI cells in the lower brainstem, i.e. substantia nigra pars lateralis, interpeduncular nucleus, inferior colliculus, nucleus cuneiformis, dorsal tegmental nucleus of Gudden, nucleus laterodorsalis tegmenti, nucleus vestibularis medialis, nucleus vestibularis inferioris, in the fasciculus longitudinalis medialis and nucleus parvocellularis compacta. We also demonstrated an extensive network of NPYI fibers in various areas of the lower brainstem including the auditory system, viscerosensory system, visceromotor system, raphe nuclei, reticular formation, parabrachial area, locus coeruleus and interpeduncular nucleus, etc. The possible importance of NPY is briefly discussed.

Animals↗

PubMed1985

Fine structure of peptidergic and catecholaminergic nerve fibers in the anterior cerebral artery and their interrelationship: an immunoelectron microscopic study.

This study shows (1) the ultrastructure of vasoactive intestinal polypeptide (VIP)-, substance P (SP)-, and neuropeptide Y (NPY)-containing nerve fibers in the walls of the cerebral arteries and (2) the relationship between these peptidergic (VIP, SP, and NPY) and catecholaminergic (CA) nerve terminals by immunohistochemistry combined with false transmitter (5-hydroxydopamine) histochemistry under the electron microscope. VIP-, SP-, and NPY-like immunoreactivity (VIPI, SPI, and NPYI) were found diffusely in the axoplasm and around the small clear vesicles in the nerve terminals. In a few cases, SPI was found within the large vesicles. Most of the VIPI terminals were ensheathed by the cytoplasm of the Schwann cells together with CA terminals, identified as those with a number of small granulated vesicles. In some cases, they were directly apposed to the smooth muscle cells at a distance of about 100 nm. SPI terminals were frequently solitary but about 30% were located together with CA and other (neither SPI nor CA) terminals ensheathed by Schwann cells, directly apposed to the smooth muscle cells at a distance of about 100 nm. On the other hand, NPYI terminals were also identified as CA terminals, indicating the coexistence of these two substances. These findings suggest a close interrelationship between peptidergic and CA nerve terminals in the neurogenic control of cerebral blood vessel function.

Animals↗

PubMed1985

Immunohistochemical localization of chick retinal 24 kdalton protein (visinin) in various vertebrate retinae.

Antiserum against a protein (24,000 daltons, visinin) of chick retina has been provided for immunohistochemical study on the localization of visinin in chick retinae during development, as well as in various vertebrate retinae. The photoreceptor cells were stained with anti-visinin serum from 7th day embryonic retinae and its intensity was gradually increased with embryonic age. In addition, visinin-like immunoreactivity was found in some kinds of amacrine and displaced amacrine cells from 11th-day embryonic retinae. When human, cat, frog and carp retinae which contain both rods and cones were examined, staining of cone cells was clearly observed in the photoreceptor cell layer, but not in the rods. Furthermore visinin-like immunoreactivity was barely detectable in the photoreceptor cells of bovine, rat and mouse retinae containing mostly rod cells. These results suggest that visinin is mainly located in the cone cells in various vertebrate retinae and is a good marker for the cone cells.

Animals↗

PubMed1985

An enkephalinergic projection from the hypothalamic paraventricular nucleus to the hypothalamic ventromedial nucleus of the rat: an experimental immunohistochemical study.

The distribution and origins of enkephalin-like immunoreactive (ENK-IR) fibers in the nucleus ventromedialis hypothalami (vm) of the rat were examined using immunohistochemistry. A dense plexus was evenly distributed in the vm with no regional differences. A group of ENK-IR neurons was concentrated in the ventrolateral portion of the vm. The destruction of the hypothalamic paraventricular nucleus (pv) which contained numerous ENK-IR neurons, resulted in a marked decrease in ENK-IR fibers in the vm on the operated side. In addition, the destruction of the magnocellular portion of the pv, while leaving most of parvocellular portion intact, failed to substantially decrease the ENK-IR fibers in the vm, suggesting that these fibers originate from ENK-IR neurons located in the parvocellular portion of the pv. The present study further showed that the axons of these neurons first proceeded laterally to the perifornical area, next ran ventrolaterally to the ventrolateral portion of the anterior hypothalamic nucleus and finally turned medially to the vm.

Animals↗

PubMed1985

An arcuato-paraventricular and -dorsomedial hypothalamic neuropeptide Y-containing system which lacks noradrenaline in the rat.

The origins of neuropeptide Y-like immunoreactive (NPYI) fibers in the paraventricular and dorsomedial hypothalamic nuclei of the rat were examined using immunohistochemistry. Destruction of the arcuate nucleus resulted in a marked decrease of NPYI fibers ipsilaterally in these nuclei, suggesting that most of NPYI fibers in these nuclei originate from NPYI neurons in the arcuate nucleus. These NPYI systems did not contain noradrenalin.

Animals↗

PubMed1985

Coexistence of calcitonin gene-related peptide and substance P-like peptide in single cells of the trigeminal ganglion of the rat: immunohistochemical analysis.

The localization of calcitonin gene-related peptide (CGRP) and substance P (SP) in the rat trigeminal ganglion was examined by means of the indirect immunofluorescent method. About 40% of neurons in the ganglion contained CGRP-like immunoreactivity (CGRPI), while about 20% of neurons showed SP-like immunoreactivity (SPI). In serial sections, nearly all the SPI neurons contained CGRPI.

Animals↗