Search PubMed⌕ Search

Biomedical subjects

M Tohyama

Publications and source records attributed to M Tohyama.

At least 415 records · Page 23Linked to original sources
PubMed1987

Ontogeny of [3H]neurotensin binding sites in the rat cerebral cortex: autoradiographic study.

The ontogeny of the neurotensin binding sites in the rat caudal cortex such as the retrosplenial cortex, the visual area containing area 17 and 18, the caudal somatosensory area and temporal area was examined by autoradiography. During the early postnatal period (from birth to day 10), very-high-density [3H]neurotensin binding sites were observed in the caudal cortical area, but the number of binding sites decreased markedly with age. On the other hand, the ventral tegmental area and substantia nigra pars compacta had a low density of binding sites at birth, but the density increased until about day 15 and remained even in the adult rat. These findings were confirmed by the biochemical binding analysis.

Animals↗
PubMed1987

Topographic localization of neuromedin U-like structures in the rat brain: an immunohistochemical study.

The distribution of neuromedin Us, uterus-stimulating and hypertensive peptides newly identified in porcine spinal cord, was examined in the rat brain by the indirect immunofluorescent method. Neuromedin U-like immunoreactive structures were found to be unevenly distributed in the neuronal system. Neuromedin U-like immunoreactive neurons were present in the cranial motor nuclei, reticular nuclei, nucleus vestibularis lateralis, trigeminal sensory nuclei, colliculus superior and inferior, lemniscus lateralis, nucleus pontis, nucleus ruber, zona incerta, substantia innominata, horizontal limb of the diagonal band and cerebral cortex. The immunoreactive fibres were found in the above areas, particularly near the labelled cells, forming a fibre plexus with various intensities of immunoreactivity. In addition, dense plexuses were also seen in the nucleus reticularis thalami, nucleus ventralis posteromedialis, nucleus ventralis posterolateralis, nucleus tegmentalis dorsalis and ventralis, vertical limb of the diagonal band, nucleus olivaris superior, and nucleus pontis. In the first six structures, no labelled neurons were present and in the remaining structures, a few scattered neurons were noted. This indicates that these fibres are probably of extrinsic origin.

Animals↗
PubMed1987

Distribution of cholinergic neurons and fibers in the hypothalamus of the rat using choline acetyltransferase as a marker.

The distribution of choline-acetyltransferase-like immunoreactive structures in the rat hypothalamus and preoptic area was examined by using avidin-biotin immunocytochemistry. We found that the hypothalamus is richly innervated by the cholinergic neuron system. Sites containing cholinergic neurons of varying density were: medial and lateral preoptic areas, septohypothalamic nucleus, median preoptic area, lateral hypothalamus including the perifornical area, anterior hypothalamic nucleus, arcuate nucleus, dorsomedial hypothalamic nucleus, posterior hypothalamic nucleus, dorsal and ventral premammillary nuclei, neuropil mediodorsal to the anterior hypothalamic nucleus, neuropil ventral to the anterior hypothalamic nucleus and ventromedial hypothalamic nucleus, neuropil between lateral hypothalamus and ventromedial hypothalamus, and neuropil between dorsal premammillary nucleus and posterior hypothalamic nucleus. There were also many varicose and non-varicose fibers in the preoptic area and hypothalamus. Two kinds of varicose fibers, one with strong immunoreactivity and the other with weak immunoreactivity, were seen. Non-varicose fibers were also detected in the optic chiasma and habenulo-interpeduncular tract. These fibers were passing fibers.

Animals↗
PubMed1987

Substance P- and enkephalin-immunoreactive neurons in the hippocampus and related areas of the human infant brain.

Neurons strongly immunoreactive for substance P are present as subpopulations in the stratum oriens, pyramidal layer and polymorphic layer of the hippocampus of the human infant. Substance P immunoreactive terminals are numerous on other neuronal cell bodies in the polymorphic layer and over pyramidal cells of the subiculum and the CA1, 2 and 3 regions. There is a high density of substance P-immunoreactive axons in the granular layer. Enkephalin immunoreactive neurons are relatively few in number and are present in the polymorphic and pyramidal layers. The results indicate that substance P probably plays a major role in short range circuits in the human hippocampus and that intrinsic enkephalin neurons probably play a relatively minor role.

Brain Mapping↗
PubMed1987

Origin of cholinergic fibers in the basolateral nucleus of the amygdaloid complex by using sensitive double-labeling technique of retrograde biotinized tracer and immunocytochemistry.

Injection of biotin-wheat germ agglutinin into the basolateral nucleus of the amygdaloid complex of the rat labeled many neurons in the substantia innomionata, ventral pallidum, horizontal limb of the diagonal band, interstitial nucleus of the ansa lenticularis, and bed nucleus of the stria terminalis. Except for the labeled cells in the bed nucleus of the stria terminalis, simultaneous staining with antiserum against choline transferase (ChAT) showed that some of these neurons are ChAT-like immunoreactive. This highest density of the double-labeled cells was seen in the horizontal limb of the diagonal band and substantia innominata, less numerous in the ventral pallidum and a few double-labeled cells in the interstitial nucleus of the ansa lenticularis.

Acetylcholine↗
PubMed1987

Immunocytochemical localization of the choline acetyltransferase containing neuron system in the rat lower brain stem.

This distribution of choline acetyltransferase (CHAT) immunoreactivity (CHAT-I) in the rat lower brain stem was analyzed using a highly sensitive avidin-biotin immunocytochemical method and 3-amino-9-ethyl-carbazole visualization. A much wider and more abundant distribution of CHAT-I structures in the lower brain stem was demonstrated than in earlier studies. The following areas were newly identified as areas rich in CHAT-I fibers: the interpeduncular nucleus, medial geniculate body, central gray matter of pons, pontine nucleus, parabigeminal nucleus, dorsal tegmental nucleus of Gudden, lateral trapezoid nucleus, inferior colliculus, dorsal and ventral cochlear nuclei, medial and lateral vestibular nuclei, reticular formation of medulla oblongata, and gelatinosa of caudal trigeminal spinal tract nucleus. In addition to the areas in which they have been known to exist, CHAT-I perikarya were found in the caudal portion of substantia nigra pars reticulata, the area between trigeminal motor nucleus and superior olivary nucleus, the medial and spinal vestibular nucleus, prepositus hypoglossal nucleus, raphe magnus and obscurus, ventromedial portion of solitary tract nucleus and its just ventral reticular formation, and caudal trigeminal spinal tract nucleus.

Animals↗
PubMed1986

Enkephalinergic projection from the ventromedial hypothalamic nucleus to the midbrain central gray matter in the rat: an immunocytochemical analysis.

The projection of enkephalin-like immunoreactive (EnkI) neurons in the ventromedial hypothalamic nucleus (VMH) in the rat was investigated using immunocytochemistry. These neurons project to the dorsal portion of the midbrain central gray matter (DCG), because the destruction of the VMH resulted in a marked ipsilateral reduction of EnkI fibers there. Destruction of the dorsomedial portion of the VMH caused the appearance of fibers accumulating EnkI ventrolateral to the lesion and these fibers could be traced to the ventrolateral portion of the VMH where many EnkI neurons were concentrated. Transection of the brain at the level of the premammillary nucleus, mammillary body and superior colliculus caused the appearance of fibers accumulating EnkI in the posterior hypothalamic nucleus (PH), central gray matter medial to the fasciculus retroflexus Mynert and in the DCG, respectively. We concluded that the axons from these neurons first project dorsomedially to situate in the PH. These fibers ran caudodorsally and entered into the dorsal longitudinal fasciculus in the DCG at the midbrain.

Animals↗
PubMed1986

The presence of vasoactive intestinal polypeptide-like immunoreactive structures projecting from the myenteric ganglion of the stomach to the celiac ganglion revealed by a double-labelling technique.

The gastrofugal vasoactive intestinal polypeptide (VIP)-like immunoreactive (VIPI) structures in the rat were examined by the combined use of immunocytochemistry and retrograde tracing. Injection of biotin-wheat germ agglutinin into the celiac ganglion labeled many neurons in the myenteric ganglion of the stomach. Simultaneous staining with antiserum against VIP showed that some of these neurons are VIPI-positive. These findings indicate that VIPI neurons in the myenteric ganglion of the rat stomach project to the celiac ganglion.

Animals↗
PubMed1986

A new method for producing a specific and high titre antibody against glutamate using colloidal gold as a carrier.

Antiserum against the glutamate was developed using colloidal gold as a carrier for the antigen. Glutamate was bound directly to colloidal gold without using cross-linking reagents such as glutaraldehyde, formaldehyde, or carbodiimide. Repeated injection of the colloidal gold-glutamate complex into the rabbit yielded a specific, high titre antiserum. Specificity was verified by radioimmunoassay and histochemically with absorption controls. The antiserum immunohistochemically detected numerous glutamate-containing neurons in the rat brain.

Animals↗
PubMed1986

Ultrastructural evidence of enkephalinergic input to glucoreceptor neurons in ventromedial hypothalamic nucleus.

A combination of intracellular injection of horseradish peroxidase into the ventromedial hypothalamic nucleus glucoreceptor neurons and immunohistochemical staining for enkephalin allowed ultrastructural visualization of interrelations between these electrophysiologically identified neurons and enkephalin-like immunoreactive (ENK-IR) terminals. The results show that glucoreceptor neurons receive direct inputs from ENK-IR neurons. This is the first evidence that glucoreceptor neurons, identified electrophysiologically, can be affected monosynaptically by endogenous enkephalin, probably released from ENK-IR terminals.

Animals↗
PubMed1986

Neurotensin immunoreactivity in the human cingulate gyrus, hippocampal subiculum and mammillary bodies. Its potential role in memory processing.

Neurotensin immunoreactive neurons comprise the majority of large perikarya in the human subiculum and project axons to the alveus, fimbria, fornix and neuropil of the mammillary bodies. These regions are prominently involved in conditions such as Wernicke's and Alzheimer's disease in which memory is impaired. Neurotensin has potential significance as a peptide in a human brain circuit which may serve a role in memory processing.

Female↗
PubMed1986

A neurotensin-immunoreactive pathway from the subiculum to the mammillary body in the rat.

The existence of a neurotensin-like immunoreactive (NT-IR) pathway from the subiculum to the mammillary body was demonstrated in very young rats using immunocytochemistry, knife cut, electric lesion and retrograde tracer techniques. Unilateral hemitransection of the dorsal fornix caused a marked reduction of NT-IR fibers in the ipsilateral mammillary body. Unilateral electric lesion of the subiculum also resulted in ipsilateral reduction of NT-IR fibers in the mammillary body. Biotin-wheat germ agglutinin (B-WGA), injected into the mammillary body, labeled neurons in the ipsilateral subiculum which were shown by double staining to have NT-IR cytoplasm. These findings demonstrate the presence of a major NT-IR fiber pathway from the subiculum to the mammillary body via the fornix.

Animals↗
PubMed1986

Two distinct calcitonin gene-related peptide-containing peripheral nervous systems: distribution and quantitative differences between the iris and cerebral artery with special reference to substance P.

The present study first shows that calcitonin gene-related peptide(CGRP)-like immunoreactive (CGRPI) nerve fibers in the cerebral arteries contained substance P (SP) and originated from small- to medium-sized CGRPI cells exhibiting SP immunoreactivity (SPI) in the trigeminal ganglion. The iris contained CGRPI/SPI-costorage nerve fibers and many CGRPI fibers lacking SPI. These fibers originated from large CGRPI cells lacking SPI in the trigeminal ganglion. The heterogenous subpopulations of CGRPI fibers in the iris suggest that CGRP is involved in a variety of functions in this structure.

Animals↗
PubMed1986

Origins and distribution of calcitonin gene-related peptide-containing nerves in the wall of the cerebral arteries of the guinea pig with special reference to the coexistence with substance P.

The origins and overall distribution of calcitonin gene-related peptide-like immunoreactivity (CGRPI) in the wall of the cerebral arteries were investigated in the guinea pig by using whole-mounts. Two types of CGRPI fibers were seen; one forming dense fiber bands, located among the periadventitial nerves, and the other forming a meshwork. CGRPI fibers in the periadventitial nerves often leave these nerves to form a meshwork, of a density that varies according to the diameter or location of the blood vessel. The present study showed that CGRPI fibers in the walls of the carotid arterial system originated from the trigeminal ganglion, and those in the vertebrobasilar arterial system from other origins besides the trigeminal ganglion. We also examined the coexistence of this peptide with substance P-like immunoreactive (SPI) structures in a single neuron system. Double staining immunocytochemistry showed that the patterns of the running of CGRPI and SPI fibers in the wall of the cerebral arteries were similar, and this method also demonstrated the presence of neurons containing both CGRPI and SPI structures in single cells of the trigeminal ganglion, which is the major origin of these fibers in the cerebral arteries.

Animals↗