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E Senba

Publications and source records attributed to E Senba.

At least 199 records · Page 11Linked to original sources

Regional distribution of substance P-like immunoreactivity in the frog brain and spinal cord: immunohistochemical analysis.

With the indirect immunofluorescence technique of Coons, the overall distribution of the substance P (SP)-positive neuron system in the frog brain and spinal cord was explored. SP-positive cells were observed in more than ten areas, such as olfactory bulb, amygdaloid complex, septal area, bed nucleus of hippocampal commissure, hypothalamic periventricular zone, dorsal and ventral thalamus, infundibulum, torus semicircularis, optic tectum, the area dorsal to the interpeduncular nucleus, central gray matter of the mesorhombencephalon, and raphe region, etc. A dense network of SP-positive fibers was also widely distributed in the frog brain and spinal cord. SP-positive fibers were roughly divided into two types. One consisted of very fine SP-positive fibers and gave the region a diffuse appearance. The area medial to n. Bellonci, interpeduncular nucleus, n. isthmi, and optic tectum contained this type of SP-positive fibers. The other one consisted of clearly distinguishable varicose fibers. A number of SP-positive fibers located in the amygdaloid complex, striatal complex, hypothalamus, central gray matter of the mesorhombencephalon, trigeminal spinal nucleus, and posterior horn of the spinal cord belonged to this category. The functional role of the SP-positive neuron system in the central nervous system is also briefly discussed.

Animals↗

New somatostatin-containing sites in the diencephalon of the neonatal rat.

Using an immunohistochemical technique, the present study demonstrated several new somatostatin-containing sites in the diencephalon of neonatal rats which have not been reported in adult animals. These areas are the area just lateral to the commissura posterior, the area between the optic tract and capsula interna, pars retrolenticularis and n. peripeduncularis.

Animals↗

Somatostatin-like immunoreactivity in the facial, glossopharyngeal and vagal lobes of the carp.

A large number of somatostatin (SRIF)-containing structures was demonstrated in the vagal and glossopharyngeal lobes of the carp by means of the indirect immunofluorescent method. The present study further showed that the facial lobe is devoid of these structures. These facts indicate that SRIF may have an important role in relaying viscerosensory information from the vagal and glossopharyngeal nerve but not from the facial nerve.

Animals↗

Somatostatin in the auditory system of the rat.

The present study clearly disclosed that the auditory system of the neonatal rat contains a large number of somatostatin (SRIF)-positive structures. Among them, n. cochlearis dorsalis and ventralis, n. ventralis lemnisci lateralis and n. parabrachialis colliculi inferioris contain huge collections of SRIF-positive neurons. Furthermore, the rat auditory system in general contains a number of SRIF-positive fibers.

Animals↗

On the afferent projections from some meso-diencephalic nuclei to n. raphe magnus of the rat.

Afferent sources from meso-diencephalon to n. raphe magnus (RM) were examined by the HRP method. Following HRP injection into RM, HRP-labeled cell clusters occurred in: (1) n.linealis rostralis; (2) ventrocaudal part of n.parafascicularis; (3) zona incerta; and (4) midbrain reticular formation. As a rule, the axons from (1) and (4) mainly terminate within RM, while those from (2) and (3) seem to project to the inferior olive (IO) as well as RM. The functional significance of these nuclei is briefly discussed.

Afferent Pathways↗

Experimental and morphological studies of te noradrenaline innervations in the nucleus tractus spinalis nervi trigemini of the rat with special reference to their fine structures.

An attempt was made to elucidate the origins and fine structure of the noradrenaline (NA) terminals in the nucleus tractus spinalis nervi trigemini (Vsp) of the rat. The present study revealed that the NA in the Vsp is supplied from two NA neuron systems; bilateral locus coeruleus (LC) and medullary NA neuron group, on the grounds that: (1) two types of fluorescent fibers (fine and coarse) were identified in the Vsp; and (2) HRP injected in to the Vsp resulted in labeling of neurons of the bilateral LC and bulbal NA areas, particularly the ipsilateral A1 area. The fine structure of the NA terminals in the Vsp was investigated by a modified potassium permanganate fixation method. The NA terminals in this area contained a number of small cored vesicles together with a small number of large cored vesicles. The most frequent feature of the NA terminals found in this area wa axo-dendritic contact. A lesser, but still substantial, number with axo-axonic contact were also noticed, in connection with which, it should be stressed that the non-NA terminals examined in this study were always presynaptic in structure, since the clear vesicles found in the non-NA terminals sometimes aggregated close to the contact membrane, where some of them fused or touched the membrane. As the dendrites showing a close relationship with the NA terminals were relatively large in size and contained a number of cytoplasmic organelles, these dendrites were assumed to be the proximal segments. At the contact zone, although no typical synaptic specialization was identified, the following profiles suggestive of synaptic-like contact were demonstrated: (1) somewhat dense material between contact membranes (intersynaptic filaments); (2) a slight accumulation of the dense materials adjacent to the postcontact membrane; (3) disarrangement of the contact membranes and enlargement of the space between these membranes; and (4) aggregation of the synaptic vesicles at the contact membrane with some of them fusing or touching the contact membrane.

Animals↗

Ascending and cerebellar non-serotonergic projections from the nucleus raphe magnus of the rat.

Non-serotonergic ascending and cerebellar projections of rat nucleus raphe magnus (RM) were disclosed using the horseradish peroxidase technique. The ascending bundle rose form rostral RM and was divided into two components; one ascended in raphe regions and the other in reticular formation. The former on innervated n. raphe dorsalis, etc., and the latter n. parafascicularis, zona incerta, etc. On the other hand, the axons innervating neocerebellum originated exclusively from caudal RM.

5,6-Dihydroxytryptamine↗

Localization of vasoactive intestinal polypeptide and neurotensin immunoreactivities in the avian retina.

The distribution of vasoactive intestinal polypeptide (VIP)- and neurotensin (NT)-like immunoreactivities in the chicken retina was investigated by immunohistochemistry. VIP- and NT-positive cells were found throughout the chicken retina. The majority of them were located in the proximal portion of the inner nuclear layer and the processes from these cells directed to the inner plexiform layer where they ramified, suggesting that VIP- and NT-positive cells located in this region probably are amacrine cells.

Animals↗

Ascending components of the medial forebrain bundle from the lower brain stem in the rat, with special reference to raphe and catecholamine cell groups. A study by the HRP method.

The afferent connection of the medial forebrain bundle (MFB) arising from the lower brain stem have been investigated by means of horseradish peroxidase (HRP) with sensitive substrate, the injection was made iontophoretically into MFB at various levels. After injection of HRP into MFB, a significant number of HRP-labeled neurons were observed in the following structures of the lower brain stem: (1) raphe nuclear group, (2) locus coeruleus, (3) n. laterodorsalis tegmenti, (4) parabrachial area, (5) A1, A2, A4, A5 and A7 areas where noradrenaline-containing neurons were disseminated, (6) A8, A9 and A10 areas which contain dopamine neurons, (7) surrounding area of the fasciculus longitudinalis medialis at the level of the n. propositus hypoglossi, (8) n. prepositus hypoglossi and (9) mesencephalic gray matter. As a rule, the ascending projections are ipsilateral and course in the medial part of MFB. Regarding the raphe nuclei, we have demonstrated that the caudal raphe nuclei, such as n. raphe magnus and obscurus (but not n. raphe pallidus), also send their axons to the hypothalamus. Particularly, the axons of n. raphe magnus ascend in MFB to reach the level of the preoptic or anterior septal areas. Furthermore, in accordance with previous reports, HRP-labeled cells were also identified in the n. raphe dorsalis, centralis superior and pontis, respectively. It should be further noted that labeled cells appeared in the n. linearis caudalis. In addition, the present study indicates a number of non-aminergic cell groups as sources of ascending mfb fibers. On the whole, the present study further clarified the organization of the components of the MFB ascending from the lower brain stem, and provided some additional anatomical substrates for the physiology of the control of the forebrain by the lower brain stem neurons.

3,3'-Diaminobenzidine↗

Topographic organization of the projection from the forebrain subcortical areas to the hippocampal formation of the rat.

Using the technique of iontophoretic microinjection of horseradish peroxidase, the present study disclosed the complexity and high degree of the topographic organization in the forebrain subcortical afferents to the different regions of rat hippocampus, e.g. diagonal band, posterior (PH), dorsomedial and rostral lateral hypothalamic nuclei chiefly project to the rostrodorsal part (DRA) and caudal gyrus dentatus including CA3, the supramammillary area predominantly to the rostroventral area (VRA), the area lateral to PH to the DRA and VRA, substantia innominata and some thalamic nuclei (n. reuniens, n. lateralis thalami, n. anterior ventralis and n. lateralis thalami pars posterior) to the dorsal subiculum, respectively.

Animals↗

Relative sparing of calcitonin gene-related peptide-containing primary sensory neurons following neonatal capsaicin treatment in the rat.

Calcitonin gene-related peptide (CGRP)-containing sensory neurons projecting to viscera or skin were detected by immunocytochemistry combined with fluorescent tracer in the dorsal root ganglia (Th9-10) of rats 5-6 weeks old treated neonatally with capsaicin. The number of CGRP-like immunoreactive (IR) cells were reduced by 50-60% with capsaicin treatment. Visceral CGRP-IR sensory neurons were shown to be more sensitive than cutaneous ones, which was also supported by the fact that CGRP-IR fibers in the stomach were completely diminished while epidermal CGRP-IR fibers were spared.

Animals↗

Cell size and cell type analysis of calcitonin gene-related peptide-containing cutaneous and splanchnic sensory neurons in the rat.

Cell size, cell type and calcitonin gene-related peptide (CGRP)-like immunoreactivity were compared between cutaneous and splanchnic sensory neurons by means of a combination of fluorescent tracer and immunohistochemistry. Nineteen percent of cutaneous sensory neurons and 88% of splanchnic sensory neurons were shown to contain CGRP. The former cells were larger than the latter ones, which was also confirmed by the finding that about a half of the former cells contained 200 kDa subunit of neurofilament protein, while only 8% of the latter ones were positively stained. These findings suggest that most of the visceral CGRP-IR sensory neurons are small type B.

Animals↗

Orofacial pain increases mRNA level for galanin in the trigeminal nucleus caudalis of the rat.

The changes of preprogalanin mRNA levels in the superficial dorsal horn neurons (laminae I and II) of the trigeminal nucleus caudalis in response to orofacial pain induced by the injection of 5% formalin into the lips of rats was investigated and compared to those of preproenkephalin A mRNA and preprodynorphin mRNA in the same region by means of in situ hybridization histochemistry. Rapid and marked increases of preprogalanin and preprodynorphin mRNA were observed on the side of the injection, but the increase of preproenkephalin A mRNA level was less pronounced than that of the other two mRNAs, indicating that these peptides have different roles in the dorsal horn analgesic mechanism and that galanin, in addition to opioid peptides, may have a highly specific role in this mechanism.

Animals↗

Effects of ethanol on the stress-induced expression of NGFI-A mRNA in the rat brain.

We investigated expression of NGFI-A/zif268 mRNA, reliable marker for neuronal activation in response to stress in the brain of rats pretreated with ethanol. The rats were orally administrated with either 25% sucrose or 20% ethanol (20 ml of kg body weight) 10 min before the onset of the stress. The rats were exposed to immobilization stress for 20 min and quickly decapitated. The brains were extracted and immediately frozen. The level of NGFI-A mRNA was evaluated by in situ hybridization histochemistry. Prior ethanol administration attenuated the immobilization stress-induced upregulation of NGFI-A mRNA level in the neocortex and hippocampus. However, in the paraventricular hypothalamic nucleus, prior administration of ethanol did not affect the upregulation of this gene. These data suggest that ethanol abolishes the forebrain component of the stress response while it fails to attenuate the stress response on a region of the brain that regulates the autonomic nervous system and the hypothalamo-pituitary-adrenal axis. Regional differences in the expression of NGFI-A mRNA may be important for the complex interactions between ethanol and stress.

Animals↗

Stress-induced elevation of the ST segment in the rat electrocardiogram is normalized by an adrenoceptor blocker.

1. Emotional stress is one of the aetiologies of cardiac accidents, but the precise mechanisms remain to be elucidated. In the present study we used the immobilization stress model in rats to investigate electrocardiographic (ECG) changes. 2. A rapid elevation of the ST segment at the II, III, aVF and precordial leads in the ECG was found and this returned to prestress basal levels after removal of stress. 3. This ECG change was normalized by combined blockade of alpha- and beta-adrenoceptors, but not by administration of a potent coronary vasodilator, such as a calcium channel blocker or nitroglycerin. 4. These results suggest that direct activation of cardiac adrenoceptors by stress may result in angina-like ECG changes.

Adrenergic alpha-Antagonists↗