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E Senba

Publications and source records attributed to E Senba.

At least 181 records · Page 10Linked to original sources

Ontogeny of somatostatin-containing neuron system of the rat cerebellum including its fiber connections: an experimental and immunohistochemical analysis.

Ontogeny of somatostatin (SRIF) neuron system of the rat cerebellum was investigated by means of the indirect immunofluorescent method. In addition, several operations were performed to provide the evidence of understanding the cerebellar SRIF innervation. SRIF-positive structures appeared in the primordium of the cerebellum of the fetus at gestational day 16 (14-15 mm embryos). From that time on, SRIF-positive structures identified in the cerebellum increased in number and the greatest number of SRIF-positive structures were detected in the cerebellum of the rat between newborn and 7-day-olds. Afterwards, these structures decreased remarkably in number and only a few if any SRIF-positive structures were observed in the cerebellum of the adult rats. These facts might suggest that SRIF might perform some important roles in the development of the cerebellum. The present study further elucidated that cerebellar SRIF was supplied by at least two types of sources; one was situated within the cerebellum and the other in the extracerebellar regions. The former one innervates mainly the vermis and partly the hemisphere, while the latter one projects mainly to the hemisphere and partly to the vermis.

Aging↗

Pathways and terminal fields of the cochlearofugal somatostatin tracts of very young rats.

The cochlearofugal somatostatin (SRIF) neuron system of very young rats (between newborn and 1 week old) was investigated by means of the indirect immunofluorescence technique of Coons. Cochlear nuclei (both dorsal and ventral cochlear nuclei) of this stage contain numerous SRIF-positive cells which are scarcely found in adult rats. Based upon the experimental findings obtained by this study, the majority of SRIF-positive fibers originating from these nuclei reach the contralateral inferior colliculus via well-established cochlearo-inferior collicular tracts such as dorsal acoustic striae, intermediate acoustic striae and trapezoid body, respectively. The possible significance of SRIF in the development of the auditory system is briefly discussed.

Animals↗

Experimental and immunohistochemical studies on the cerebellar substance P of the rat: localization, postnatal ontogeny and ways of entry to the cerebellum.

With the indirect immunofluorescence technique, the localization (including the postnatal ontogeny) of substance P in the cerebellum, and the ways of entry of substance P-containing fibers into the cerebellum were explored. In the newborn rat cerebellum, dense fiber bands of axons with substance P-like immunoreactivity which can be traced to the lower brain stem are found. These fibers are also traceable to the developing granular cell layer. Two weeks after birth, however, substance P-containing structures seen in the cerebellum begin to decrease progressively and in the cerebellum of the adult rats, only a small amount of substance P-containing structures is observed. The present study established that substance P-containing fibers are mostly derived from extracerebellar substance P-containing cells and demonstrated the presence of three sites of entry of these substance P-containing fibers to the cerebellum, via (1) the inferior cerebellar peduncle, (2) the fasciculus uncinatus and (3) the middle cerebellar peduncle, respectively. Following deafferentation of the cerebellum, substance P-accumulating fibers are observed only ventral to the lesion (i.e. on the brain stem side), while in the cerebellum a remarkable decrease of substance P-containing fibers is seen and no substance P-accumulating fibers are found dorsal to the lesion (cerebellar side).

Afferent Pathways↗

Ontogeny of substance P-containing neuron system of the rat: immunohistochemical analysis--I. Forebrain and upper brain stem.

The ontogeny of substance P-containing neuron system in the forebrain and upper brain stem of the rat was investigated by means of the indirect immunofluorescence technique. Substance P-positive structures first appeared in the primordium of the epithalamus and the area which surrounded the commissura posterior of the rat fetus corresponding to gestational day 14 (10-12 mm embryos). On and after gestational day 14, substance P-positive structures gradually made their appearance in various areas of the forebrain and upper brain stem. Substance P-positive structures thus continued to increase in number and in density during the fetus and perinatal stage and showed histochemically maximum content at the stage between postnatal days 5 and 15. After then, substance P-positive neurons tended to decrease in number as the rats grew, while substance P-positive fibers maintained in general their strong immunoreactivity even in the adult rats. The present study demonstrates that substance P-positive structures appear at a very early ontogenetical stage. This suggests that substance P might play an important role in the development of the forebrain and upper brain stem in addition to its neurotransmitter or neuromodulator functions.

Age Factors↗

Ontogeny of substance P-containing neuron system of the rat: immunohistochemical analysis--II. Lower brain stem.

Ontogeny of the substance P neuron system in the lower brain stem of the rat was investigated by means of the indirect immunofluorescence technique. Substance P-positive structures (cells and fibers) first appeared in the primordium of the ventral part of the nucleus tractus spinalis nervi trigemini (nVs), in the reticular formation between nucleus reticularis lateralis and nVs, and in the reticular formation between nVs and nucleus originis nervi facialis, respectively, at gestational day 14. After that time, substance P-positive structures made their appearance gradually in various areas of the lower brain stem. The present study demonstrates that substance P-positive structures appear at a very early ontogenetical stage, which suggests that substance P may play a role in the development of the lower brain stem in addition to its role as a neurotransmitter or neuromodulator.

Aging↗

Localization of LH-RH immunoreactivity in the avian retina.

The present study demonstrated numerous LH-RH--positive structures in the paddy-bird (padda orizivora) retina. LH-RH-positive cells were seen in the ganglion cell layer (GL), inner plexiform layer (IPL) and inner nuclear layer (INL). Judging from the morphological features, the former two types of cells may belong to the displaced amacrine cells and the latter to the amacrine cells. LH-RH-positive fibers were found in the nerve fiber layer, GL, IPL, INL and outer plexiform layer.

Animals↗

Regional distribution of somatostatin-containing neuron system in the lower brain stem of the neonatal rat.

With the indirect immunofluorescence technique, overall distribution of somatostatin (SRIF) neuron system in the lower brain stem of the neonatal rats were examined. The present study demonstrated numerous SRIF-positive structures in various lower brain stem areas which are hardly seen in the adult lower brain stem. A possible role of SRIF in the lower brain stem was briefly discussed.

Animals↗

Phylogenetical development of somatostatin-containing cells in the retina from teleosts to mammals: immunohistochemical analysis.

The distribution of somatostatin (SRIF) in the retina of various vertebrates (from teleosts to mammals) was investigated by means of indirect immunohistochemical technique. The present study revealed that there exists marked differences in topography of SRIF-containing cell systems between higher vertebrates (birds and rats) and lower vertebrates (amphibian and teleosts). The retinas of the higher vertebrates contain abundant SRIF-positive structures, while those of the lower vertebrates contain a few. Phylogenetical development of retinal SRIF-system was briefly discussed in this study.

Animals↗

Localization of substance P-like immunoreactivity in the anterior eye segment of squirrels: an immunohistochemical analysis.

Localization of substance P (SP)-like immunoreactivity in the anterior eye segment of the squirrel was examined immunohistochemically. The present study demonstrates a dense network of SP-positive fibers in the ciliary body, particularly in the muscle layers, and several SP-positive fibers in the iris, in addition to scattered SP-positive fibers in the cornea. These facts strongly suggest that SP has an important role in the physiologic functions of the anterior eye segment.

Animals↗

Overall distribution of glucagon-like immunoreactivity in the chicken retina: an immunohistochemical study with flat-mounts.

Pancreatic glucagon-like immunoreactivity (GLI) in the chicken retina was investigated by immunohistochemical methods with frozen sections and flat-mounts. Observations of the frozen sections showed that GLI is localized in the amacrine cells. Flat-mounts showed the GLI cells are evenly localized in the retina (n= or approximately 400/mm2) and composed to two types of cells--one is larger and the other is small. The former cell type occupies mainly the peripheral retinal region and the latter the central region. In addition, flat-mounts showed two types of GLI fiber plexuses in the inner plexiform layer; one is located in the area between laminae 2 and 3 and runs circularly and the other is located in lamina 1 and runs randomly. The relationship between GLI and cyclic AMP was also examined. an increase of the formation of cyclic AMP was caused by pancreatic glucagon in the chicken retina, suggesting that this peptide might have neurotransmitter or neuromodulator roles in the chicken retina.

Animals↗

Ontogeny of somatostatin-containing neuron system of the rat: immunohistochemical observations. I. Lower brainstem.

The ontogeny of the somatostatin (SRIF) neuron system in the lower brainstem of the rat was analyzed using the indirect immunofluorescence technique of Coons. SRIF-positive structures first appeared in the primordium of the ventral nucleus of the lemniscus lateralis of the rat fetus corresponding to gestational day 15 (12-14-mm embryos). On and after gestational day 15, these structures appeared in progressively more diverse areas of the lower brainstem and continued to show an increase in number and intensity up till birth. The maximum SRIF-positive structures were histochemically identified in the lower brainstem at the perinatal stage. However, after birth, the numbers of SRIF-positive structures in the lower brainstem began to decrease as the rat grew and none or only a few SRIF-positive structures were detected in the adult rats. This ontogenetical study of the SRIF neuron system on the lower brainstem of the rat strongly suggests that SRIF might play an important role in the development of the lower brainstem other than in its neurotransmitter or neuromodulator function.

Aging↗

Morphological study of noradrenaline innervation in the caudal raphe nuclei with special reference to fine structure.

Previous histofluorescence studies have demonstrated that the caudal raphe nuclei (CRa) of the rat, particularly the ventral portion (VCRa), contains a very high density of noradrenaline (NA) terminals and in the present study we attempted to elucidate the origins and free structure of the NA terminals in this region. The majority of NA terminals found in the VCRa originated from A1 and A3 NA neurons and disclosed that a small number of very strongly fluorescent fibers located along the blood vessels arise from the superior cervical ganglion (SGC). Electron microscopic analysis after potassium permanganate fixation demonstrated that the NA terminals originated from A1 and A3 NA neurons are connected with neuronal elements, while NA fibers from the SGC were identified among the vascular elements. Axodendritic contacts were found to be predominant among the synapselike contacts of NA terminals in this area.

Animals↗

Distribution of somatostatin in the frog brain, Rana catesbiana, in relation to location of catecholamine-containing neuron system.

The distribution of somatostatin (SRIF)-immunoreactive structures in the central nervous system of the bull frog (both with and without treatment of colchicine) was studied, using the indirect immunofluorescence technique of Coons and co-workers (Coons, '58). SRIF-containing cells were observed in more than ten areas including the spinal cord. These SRIF-positive cells showed segmental distribution, in that SRIF-positive neurons were identified in various areas at various brain levels. An extensive network of SRIF-positive fibers was found in most parts of the central nervous system. The distribution of a catecholamine (CA)-containing neuron system in the frog brain is also presented in this study. The possible interactions between SRIF and CA neurons systems are briefly discussed.

Animals↗

Topographic atlas of somatostatin-containing neurons system in the avian brain in relation to catecholamine-containing neurons system. I. Telencephalon and diencephalon.

The morphological organization of the somatostatin (SRIF)-positive neurons in the forebrain (telencephalon and diencephalon) of the warbling grass parakeet (Melopsittacus undulatus) was studied using the indirect immunohistochemical technique of Coons and co-workers ('58). In the telencephalon, a number of SRIF-positive neurons was detected in the lobus paraolfactorius, hippocampus, and paleostriatum. Furthermore, scattered SRIF-labeled cells were noticed in the area corticoidea dorsolateralis and area temporoparieto-occipitalis. A moderate density of immunoreactive fibers was found in the above areas. In addition, although the septal areas was devoid of SRIF-positive neurons, this area contained a moderate occurred in the following hypothalamic areas: (1) nucleus medialis hypothalami posterior, (2) lateral hypothalamus, and (3) mammillary nucleus. The bird hypothalamus also received a strikingly massive SRIF innervation. The heaviest concentration of SRIF-labeled fibers was detected in the medial eminence. Many SRIF-labeled fibers were also observed in other hypothalamic regions. Their locations roughly corresponded in many cases to the areas in which SRIF-positive neurons were disclosed. The overall distribution of the catecholamine system (CA) of the avian forebrain is also represented by means of histofluorescent technique. A possible interaction between SRIF and CA neurons systems is briefly discussed.

Animals↗

Topographic atlas of somatostatin-containing neuron system in the avian brain in relation to catecholamine-containing neuron system. II. Mesencephalon, rhombencephalon, and spinal cord.

With the indirect immunofluorescence technique of Coon's and collaborators, overall distribution of the somatostatin (SRIF)-positive neurons system in the avian lower brain stem was explored. Numerous cell somata containing SRIF were identified in the interpeduncular nucleus and substantia grisea centralis (GCT) at the level of the nucleus nervi trochlearis. Furthermore, a moderate number of SRIF-positive neurons were seen in the tectum opticum, nucleus tractus solitarii, and spinal cord. Scattered labeled cells were noticed in the rhombencephalon. A dense network of SRIF-positive fibers was distributed widely in the lower brain stem of birds. Their locations corresponded in many cases to the areas where SRIF-positive neurons were found. The present study also presents the distribution of the catecholamine (CA) neuron system in the avian lower brain stem. Possible interactions between SRIF and CA neurons systems are briefly discussed.

Animals↗

Comparative anatomy of the distribution of catecholamines within the inferior olivary complex from teleosts to primates.

The distribution of catecholamine (CA) in the inferior olivary complex (IO) of various vertebrate (from fish to monkey) was investigated by means of the histofluorescence technique. In addition, using rats, a further attempt was made to elucidate the origins of CA in the IO. The IO of the lower vertebrates (from fish to birds) was in general poorly innervated by the CA neuron system. IO in the lower mammals, such as insectivora and bats, contained only a few CA nerve terminals, while that in the higher mammals such as rat, guinea pig, rabbit, cat, and monkey revealed quite a number. In these animals, species-species patterns of CA nerve terminals were found. In the rat, the highest concentration was observed in the dorsal lamella of the principal nucleus and in guinea pig ventral lamella. In the rabbit and cat, maximum CA nerve terminals were detected in the dorsal accessory nucleus, while in the monkey, they were detected in the medial accessory nucleus. The retrograde tracer technique of horseradish peroxidase (HRP) suggested that the main source of the abundant CA terminals in IO of the rat might be A1, A2, and A3 noradrenaline neurons, though not locus coeruleus and not dopaminergic ones.

Animals↗

Experimental immunohistochemical studies on the amygdalofugal peptidergic (substance P and somatostatin) fibers in the stria terminalis of the rat.

The amygdalofugal substance P (SP) and somatostatin (SRIF) neuron systems in the stria terminalis (ST) were investigated by means of the indirect immunofluorescence technique of Coons. SP- and SRIF-positive cells were mainly located in the area (Amc) between the central (ac) and medial (am) amygdaloid nuclei. Some extended medially into the am and laterally into the ac. Destruction of the Amc resulted in a marked reduction of SP- and SRIF-positive fibers in the ST. Furthermore, a substantial decrease in SP-positive fibers was seen in the dorsal part of the bed nucleus of the ST (stb), there was a small decrease in the SP-positive fibers in the lateral hypothalamus (LH), a significant decrease in the SRIF-positive fibers in the lateroventral part of the anterior hypothalamic nucleus (lvAH), and a small decrease in the SRIF-positive fibers in the LH. These facts indicate that the origins of a number of SP- and SRIF-positive fibers are the Amc and that the amygdalofugal SP pathway in the ST innervates stb and LH and the amygdalofugal SRIF pathway in the ST projects to lvAH and LH.

Amygdala↗