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Biomedical subjects

Y Sano

Publications and source records attributed to Y Sano.

At least 397 records · Page 22Linked to original sources

Immunohistochemical study on the distribution of serotonin fibers in the spinal cord of the dog.

Distribution of serotonin fibers in the spinal cord of the dog was investigated by means of a modified PAP method; a rabbit anti-serotonin serum prepared in the laboratory of the authors was used in this study. Serotonin fibers were revealed as PAP-positive dark-brown elements displaying dot-like varicosities (0.5--2.0 micrometers in diameter). In the spinal cord of the dog, the distribution of serotonin fibers is extensive. These fibers occur more densely in more caudal segments and are most prominent at the sacrococcygeal level. From the level of the cervical spinal cord to the upper lumbar region, the descending serotonin fibers are located immediately under the pia mater in the ventrolateral portion of the lateral funiculus. In more caudal segments, serotonin fibers are dispersed throughout the ventral and lateral funiculi. These longitudinal en passage-fibers send numerous transverse collaterals to the gray matter. Serotonin fibers are distributed abundantly in the laminae I and III of the posterior column, while only a few fibers are found in the lamina II (substantia gelatinosa). In the intermediate zone, two descending serotonin pathways, i.e., lateral and medial longitudinal bundles, are observed to coincide topographically with the nucleus intermediolateralis at C8(T1)--L3(L4) and the nucleus intermediomedialis at C1--Co respectively. The former is particularly prominent and communicates with the contralateral bundle via commissural bundles at intervals of 300--500 micrometers. The large motoneurons in the anterior column, especially those in the nucleus myorabdoticus lateralis within the cervical and lumbar enlargements, are closely surrounded by fine networks of serotonin fibers and terminals.

Animals↗

Morphological studies on neuroglia. VI. Postnatal development of microglial cells.

The postnatal development of microglial cells was investigated in the neonatal rat brain by use of light- and electron microscopy, including enzyme-histochemical techniques. Microglial cells were selectively stained by demonstration of their nucleoside diphosphatase (NDPase) activity and classified into three types: 1) In the early postnatal period "primitive microglial cells" showing scantily ramified processes were found in the cerebral cortex, the hippocampal formation, and the hypothalamus. During the course of the first postnatal week the processes of this cell type developed gradually and the cells were transformed into typical ramified microglial cells, called "resting microglial cells". 2) "Amoeboid microglial cells "showing typical features of macrophages were characteristic of the cerebral white matter. 3) "Round microglial cells" possessing a round soma and few pseudopodia but no characteristic processes occurred in large numbers in the subventricular zone of the lateral ventricle and as single elements in the vicinity of blood vessels. Histochemically, thiamine pyrophosphatase (TPPase) was demonstrated only in the fully developed, ramified microglial cells ("resting microglial cells"), which could be readily observed in the central nervous tissue from the age of 14 day. "Round and amoeboid microglial cells" did not show TPPase activity and disappeared after 14 days of postnatal life. By use of electron microscopy, in neonatal rats NDPase activity was apparent in the plasma membrane of the three types of microglial cells ("primitive, round, and amoeboid" types). They showed basically similar submicroscopic characteristics, i.e., well-developed Golgi apparatus, long strands of rough-surfaced endoplasmic reticulum, single dense bodies and vacuoles, and numerous ribosomes. "Amoeboid microglial cells" were characterized by their well-developed cytoplasmic vacuoles and phagocytic inclusion bodies. The present study strongly suggests a mesodermal origin for these microglial elements.

Aging↗

Immunohistochemical demonstration of the distribution of serotonin neurons in the brainstem of the rat and cat.

The morphological characteristics and distribution of the somata of serotonin-containing neurons in the brainstem of rats and cats were studied by use of the peroxidase-anti peroxidase (PAP) immunohistochemical method employing highly specific antibodies to serotonin. Antibodies were raised in rabbits against an antigen prepared by coupling serotonin to bovine thyroglobulin and using formaldehyde as the coupling reagent. The distribution pattern of serotonin neurons observed in the present material is essentially in agreement with that described by other investigators who used the Falck-Hillarp method. In addition, this immunohistochemical technique revealed serotonin-containing perikarya in the following regions: 1) the periaqueductal gray, especially lateral to the nucleus raphe dorsalis, 2) the nucleus interpeduncularis, 3) the nucleus parabrachialis ventralis and dorsalis, 4) the field of the lemniscus lateralis, and 5) the reticular formation of the pons and medulla oblongata. The described immunohistochemical procedure makes it possible to study central serotonin neurons in detail without pharmacological pretreatment. The wide distribution of serotonin neurons demonstrated in this study should be considered when interpreting experiments dealing with the serotonin system.

Animals↗

Immunohistochemical demonstration of serotonin-containing nerve fibers in the cerebellum.

The localization of serotonin (5-HT)-immunoreactive nerve fibers in the cerebellum of the rat and cat was investigated by means of the peroxidase-anti-peroxidase (PAP) method using highly specific antibodies to 5-HT. Serotonin-containing nerve fibers were distributed throughout the entire cerebellum including the deep cerebellar nuclei, while 5-HT-positive neuronal somata were not detected in the cerebellum of either species. A different pattern of 5-HT innervation was found among the three layers of the cerebellar cortex. There were also interspecific differences in the pattern of distribution of 5-HT. In the rat, the pool of 5-HT nerve fibers mainly consisted of tangential elements, which were predominant in the molecular layer, while in the cat only a few 5-HT fibers were found in the molecular layer of the cerebellar cortex; dense networks of 5-HT nerve fibers were present in the granular layer. Some differences are evident in the pattern of distribution of 5-HT fibers in cerebellar regions classified on an anatomical and functional basis.

Animals↗

Morphological studies on neuroglia. IV. Proliferative response of non-neuronal elements in the hippocampus of the rat to kainic acid-induced lesions.

Autoradiographic studies showed that in the rat hippocampus "microglia-like reactive cells" (MRS) and astrocytes are capable of proliferation in response to kainic acid (KA)-induced lesions. A marked increase in the number of labeled MRC was observed during the first four days after the induction of the KA-lesion. A proliferative response of astrocytes occurred at two days after the KA-lesion. After the induction of a KA-lesion brain macrophages and oligodendrocytes were only slightly labeled with 3H-thymidine. It appears likely that MRC is the main cellular element responding to this type of lesion.

Animals↗

Morphological studies on neuroglia. V. Microglial cells in the cerebral cortex of the rat, with special reference to their possible involvement in synaptic function.

Electron-microscopic survey of selectively stained microglial cells in the cerebral cortex of the rat reveals that the processes of this cell type often encircle axo-dendritic synapses. Enzyme-histochemical methods for thiamine pyrophosphatase (TPPase) or nucleoside diphosphatase (NDPase) were used for the selective marking of the microglial cells; TPPase and NDPase activities were observed in the plasma membrane of microglial cells. The synapses encircled by microglial processes displayed presynaptic structures containing round clear vesicles (50 nm in diameter) and a prominent thickening of the postsynaptic membrane. In vitro, the above-mentioned enzymatic activities were completely suppressed by neuroactive agents such as catecholamines and phenothiazine derivatives. Examination using enzyme-histochemical techniques suggests that a single enzyme may be responsible for both microglial cells in the normal central nervous tissue is discussed.

Acid Anhydride Hydrolases↗

Immunohistochemical identification of the oxytocin and vasopressin neurons in the hypothalamus of the monkey (Macaca fuscata).

The hypothalamic oxytocin and vasopressin neurons of the monkey, Macaca fuscata, were demonstrated in Golgi-like images by a modified immunoperoxidase method. The magnocellular oxytocin and vasopressin neurons were distributed mainly in the supraoptic and paraventricular nuclei. In addition to these main nuclei, both types of magnocellular neurons were found in the accessory supraoptic nucleus, the periventricular and perifornical areas, the nucleus of the stria terminalis, the lateral hypothalamic area, and the pars interna of the globus pallidus. Magnocellular oxytocin neurons were seen immediately ventral to the anterior commissure, and parvocellular vasopressin neurons were localized in the medial portion of the suprachiasmatic nucleus. The preferential distribution of the oxytocin and vasopressin neurons was recognized not only in the supraoptic and paraventricular nuclei, but also in other areas. In all areas observed, the cytological difference between the oxytocin and vasopressin neurons could be identified. The area of the perikarya of the vasopressin neurons was determined to be larger than that of the oxytocin neurons. Most of the axons of the oxytocin neurons issued from the perikarya, while the axons of the vasopressin neurons originated in most cases from the thick proximal dendrites. These results show that the oxytocin and vasopressin neurons are distributed in areas much broader than has hitherto been assumed, and that these two peptidergic neurons can be definitely differentiated morphologically as well as functionally.

Animals↗

Immunohistochemical demonstration of the localization of corticotropin releasing factor-containing neurons in the hypothalamus of mammals including primates.

The presence of the CRF-containing neurons in the hypothalamus was investigated in four different species (cats, dogs, pigs, and monkeys) by the peroxidase-antiperoxidase technique using specific antiserum to CRF. In all animals examined, CRF-containing perikarya were found mainly in the paraventricular and supraoptic nuclei, and a small number of the immunoreactive cells were observed in the accessory supraoptic nucleus and the lateral hypothalamic area. The size of the CRF-containing perikarya ranged from 20-35 micron in diameter. These findings suggest that the magnocellular paraventricular and supraoptic nuclei are the center not only of the classical neurosecretory system for the production of the posterior lobe hormones, but also that of the CRF neuronal system.

Animals↗

Immunohistochemical demonstration of corticotropin releasing factor containing nerve fibers in the median eminence of the rat and monkey.

By means of the peroxidase-antiperoxidase technique, in conjunction with a specific anti-CRF serum, it was shown that a large number of immunoreactive nerve fibers were demonstrable on the capillary loops of the hypophysial portal vessels in the external layer of the median eminence of the rat and monkey, particularly in its medial part. This result confirms the radioimmunological determination of CRF immunoreactivity in the median eminence.

Animals↗

Immunohistochemical demonstration of EC cells in rat gastrointestinal tract.

Selective immunohistochemical demonstration of enterochromaffin (EC) cells in the rat gastrointestinal tract has been carried out, using a highly specific rabbit antiserotonin (5-HT) serum and the unlabeled peroxidase-antiperoxidase complex (PAP) technique. The daily profile of the EC cell density was also studied using this method. No significant change was recorded.

Animals↗

Immunohistochemical demonstration of serotonin nerve fibers in the cat neurohypophysis.

Distribution of the serotonin nerve fibers in the neurohypophysis of adult cats was demonstrated using the peroxidase-antiperoxidase method. The serotonin nerve fibers were distributed in the internal and external layers of the infundibulum, terminating on the wall of the capillary loops and the outer surface of the external layer. A small number of the fibers scattered about in the posterior lobe penetrated the intercellular spaces in the intermediate lobe.

Animals↗

Immunohistochemical studies on the serotonergic innervation of the pia mater.

The direct innervation of the pial blood vessels by serotonin neurons has been demonstrated with a modified peroxidase-antiperoxidase technique in the mammalian central nervous system. The pia mater covering the ventrolateral surface of the medulla oblongata is innervated by numerous varicose serotonin fibers originating from the serotonin neurons of the lower brainstem. Scattered serotonin fibers were observed in the pia mater in every part of the brain and spinal cord.

Animals↗

Immunohistochemical demonstration of serotonin nerve fibers in the olfactory bulb of the rat, cat and monkey.

The distribution of serotonin (5-HT) positive fibers in the olfactory bulb of the rat, cat and monkey was studied using the peroxidase-anti-peroxidase (PAP) immunohistochemical method and highly specific antibodies to 5-HT. In general, 5-HT fibers were present throughout all layers in the olfactory bulb of these species except for the olfactory nerve layer and different as well as restricted laminar patterns of 5-HT distribution were observed. There were also species-related differences in the pattern of 5-HT distribution, in each layer. The most notable species difference was apparent in the glomerular layer of the main olfactory bulb. In case of the rat and cat, a very dense plexus of 5-HT fibers was observed to be diffuse in the glomerulus, while in the monkey, the distribution of 5-HT fibers was scanty and partial, as was seen in the accessory olfactory bulb of the rat.

Animals↗

Metabolism of [14C]-C21 steroids in the human fetal ovaries.

The incubation of [14C]-pregnenolone with the mince of human fetal ovary produced progesterone. 17-hydroxypregnenolone, 5-pregnene-3 beta, 20 alpha-diol. 5-pregnene-3 beta, 17 alpha, 20 alpha-triol and 5 alpha-pregnan-3,20-dione. The other 7 tissues, uterus, liver, intestine, skin, kidney, lung and pancreas, obtained from the same fetus were also able to produce some of these metabolites. When [14C]-pregnenolone, progesterone or 17-hydroxyprogesterone was incubated with 800 g supernatant of fetal ovaries, progesterone, 17-hydroxypregnenolone and 5-pregnene-3 beta, 20 alpha-diol were formed from pregnenolone, 17-hydroxyprogesterone and 20 alpha-hydroxy-4-pregnen-3-one were formed from progesterone and 17 alpha, 20 alpha-dihydroxy-4-pregnen-3-one was formed from 17-hydroxyprogesterone. These results indicate that the fetal ovary has the activities of 5-ene-3 beta-hydroxysteroid dehydrogenase, 17-hydroxylase, 20 alpha-hydroxysteroid dehydrogenase and 5 alpha-reductase.

17-alpha-Hydroxypregnenolone↗

Two new slow-moving variants of human serum albumin.

Two new slow-moving variants of human serum albumin were found in members of two unrelated Japanese families. These variants, different from each other and from the slow-moving variants described previously, were designated albumin "Okinoerabu' and albumin "Akasaka'. The mode of inheritance of each variant was consistent with an autosomal codominant trait. A very rare type, homozygote for a variant, albumin "Okinoerabu', was also detected. The segregation data of albumin and Gc showed no discrepancy from the postulation of a linkage between these two loci.

Electrophoresis, Agar Gel↗