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E Senba

Publications and source records attributed to E Senba.

At least 109 records · Page 6Linked to original sources
PubMed1992

Axonal flow blockade induces alpha-CGRP mRNA expression in rat motoneurons.

Axonal flow of motoneurons was blocked in the sciatic nerve by the application of vinblastine at a low concentration (100 microM) not considered likely to cause axonal degeneration. The number of motoneurons expressing alpha-calcitonin gene-related peptide (CGRP) mRNA was significantly increased by vinblastine application, while the expression of beta-CGRP mRNA was not influenced. These findings suggest that the synthesis of these two peptides is differentially regulated and that alpha-CGRP mRNA is possibly down-regulated by unknown factor(s) which normally undergo retrograde transport from the periphery.

Animals↗
PubMed1992

Co-localized but target-unrelated expression of vasoactive intestinal polypeptide and galanin in rat dorsal root ganglion neurons after peripheral nerve crush injury.

Expression of vasoactive intestinal polypeptide (VIP) and galanin in dorsal root ganglion (DRG) neurons is known to be induced by peripheral nerve injury. We investigated (1) whether VIP and galanin were co-expressed by DRG neurons and (2) whether such neurons innervated specified peripheral targets (visceral, cutaneous or muscular). An antibody to the 200 kDa neurofilament subunit (NF200) was used as a marker for large type-A cells in the DRG. VIP and galanin were respectively observed in 22% and 67% of DRG neurons at the L5 spinal level after crushing of the sciatic nerve. Most VIP-containing neurons were small type-B cells (about 90%) and approximately 95% of VIP-containing neurons also showed galanin-like immunoreactivity. Galanin was expressed by both large type-A and small type-B cells. Immunocytochemistry combined with a retrograde tracer revealed that about 70-80% of the small type-B cells in each sensory division displayed VIP-like immunoreactivity, and that most of the tracer-labeled neurons also expressed galanin. These findings suggest that the expression VIP and/or galanin in response to peripheral nerve crush injury is a property common to visceral, cutaneous and muscular sensory neurons.

Animals↗
PubMed1992

Axonal blockade induces the expression of vasoactive intestinal polypeptide and galanin in rat dorsal root ganglion neurons.

Nerve growth factor (NGF) undergoes retrograde transport from peripheral target organs, and has been recently reported to regulate the production of some neuropeptides in dorsal root ganglion (DRG) neurons. Therefore, to ascertain whether or not the expression of calcitonin gene-related peptide (CGRP), vasoactive intestinal polypeptide (VIP), and galanin was regulated by the retrograde transport of factors such as NGF, we carried out an immunocytochemical analysis using vinblastine as an axonal transport blocker and a monoclonal antibody to the NGF receptor (NGFR) as a marker of NGF-responsive neurons. The percentage of CGRP-containing DRG neurons (L5) was decreased by sciatic nerve transection or by the application of higher doses of vinblastine (0.3-0.6 mM) to the sciatic nerve. VIP and galanin were expressed in some DRG neurons after the application of a low dose of vinblastine (0.15 mM), which can block axonal flow without causing neuronal damage. The expression of these peptides was not affected by dorsal rhizotomy. About 70% of the CGRP-containing neurons also expressed NGFR, while most of the VIP-containing or galanin-containing neurons lacked NGFR. These findings indicate that the depletion of peripheral target-derived neurotrophic factor(s) other than NGF by axonal blockade may induce the gene expression of VIP and galanin.

Animals↗
PubMed1991

Ultrastructure and retinal innervation of deafferentation-induced enkephalin-immunoreactive elements in the superficial layers of the rat superior colliculus.

Leu-enkephalin-like immunoreactive (ENK-I) elements appearing in the superficial layers of the rat superior colliculus (SC) after eye-enucleation were examined by means of immunoelectronmicroscopy. ENK-I somata were of a single type and formed symmetric and asymmetric synapses with non-immunoreactive axon terminals. Some degenerating retinal terminals made synaptic contacts only with small ENK-I dendrites, suggesting that deafferentation-induced ENK-I neurons in the rat SC receive retinal input onto the distal portions of their dendrites.

Afferent Pathways↗
PubMed1991

Enkephalinergic sympathetic and parasympathetic innervation of the rat submandibular and sublingual glands.

Enkephalinergic innervation of the rat salivary glands was investigated by immunocytochemical techniques. Based upon immunostaining for enkephalin (ENK) and tyrosine hydroxylase (TH), 4 types of neurons could be distinguished in the submandibular ganglion: cells containing both ENK and TH (9% of all ganglion cells), cells containing only ENK (17%), cells containing only TH (4%) and cells lacking both ENK and TH (70%). Almost all of the ganglion neurons were also positive for AChE and so were most of the TH-positive cells. The ENK-positive fibers outnumbered the TH-positive fibers. Although TH-positive fibers displayed concurrent ENK immunoreactivity, fibers in the blood vessel walls were only immunoreactive for TH. Excision of the superior cervical ganglion resulted in a decrease of ENK fibers and the disappearance of most of the TH fibers from the submandibular gland. Most of the remaining ENK-positive fibers were immunonegative for TH, while the remaining TH-positive fibers were also positive for ENK. The salivary gland of the postnatal 8-week-old rats had a considerable number of ENK-positive neurons and fibers in the submandibular ganglion and acini.

Acetylcholinesterase↗
PubMed1991

Fine structure of synapses and retinal innervation of substance P and adenosin deaminase containing neurons in the superior colliculus of the rat.

The fine structure of substance P (SP) and adenosine deaminase (ADA) immunoreactive structures in synaptic contacts localized to the superficial layers of the superior colliculus of the rat was investigated by means of immunoelectron microscopy. We also examined the possibility of retinal innervation of SP- and ADA- containing neurons by immunohistochemistry after degeneration of retinal terminals caused by enucleation. SP-like immunoreactive presynaptic terminals of the stratum griseum superficiale (SGS) formed both asymmetric and symmetric synaptic contacts. Presynaptic dendritelike structures were also observed. SP immunoreactive postsynaptic elements made contacts with terminals showing diverse features. ADA-like immunoreactive structures were seen only as postsynaptic elements to different kinds of nonimmunoreactive terminals and were mostly localized in the ventral third of the SGS and the dorsalmost stratum opticum (SO). After enucleation, degenerating retinal terminals were found to form synaptic contacts with SP and ADA immunoreactive structures. The highest number of such degenerating terminals on ADA immunoreactive structures was observed 2 days after retinal denervation, very few being seen after 5 days. These degenerating terminals were restricted to the ventral SGS and dorsal SO. SP immunoreactive structures postsynaptic to degenerating retinal terminals were most numerous 5 days after enucleation and mainly localized in the dorsal SGS. Occasionally, SP immunoreactive dendritelike processes forming synapses with degenerating retinal terminals were simultaneously presynaptic to other nonimmunoreactive profiles, defining, therefore, serial synapses. The present results suggest that SP-I and ADA-I collicular neurons may be part of distinct channels carrying visual information to the lateral posterior and lateral geniculate nuclei of the thalamus, respectively.

Adenosine Deaminase↗
PubMed1991

Changes in expression of peptides in rat facial motoneurons after facial nerve crushing and resection.

In situ hybridization histochemistry was used to study changes in mRNAs coding neuropeptides such as alpha-calcitonin gene-related peptide (CGRP), beta-CGRP, cholecystokinin (CCK) and galanin, in rat facial motoneurons following axotomy of the facial nerve. In control rats, 38%, 55% and 7% of the facial motoneurons expressed alpha-CGRP, beta-CGRP and CCK mRNAs, respectively. No galanin mRNA-containing motoneurons were observed in these animals. The levels of mRNA for alpha-CGRP, CCK and galanin were increased while the beta-CGRP mRNA level was decreased after axotomy. The levels of mRNAs for these peptides returned to the control values by 2-4 weeks after nerve crush, whereas nerve resection had more prolonged effects. Within 3-4 weeks after injury, nerve resection had greater effects on beta-CGRP, CCK and galanin mRNAs than did nerve crush. Thus, there appear to be differences in the regulation of mRNA expression of these peptides in axotomized motoneurons.

Animals↗
PubMed1991

Effects of nerve crush and transection on mRNA levels for nerve growth factor receptor in the rat facial motoneurons.

We found that the level of nerve growth factor receptor (NGF-R) mRNA in facial motoneurons was increased after both facial nerve crushing and transection by means of in situ hybridization histochemistry. The increased level of NGF-R mRNA was maintained for at least 8 weeks after facial nerve transection, while facial nerve crushing caused only a transient increase. Thus, expression of NGF-R mRNA paralleled the axonal regeneration process. In addition, the increase of NGF-R mRNA with crushing was more pronounced than with transection from the 3rd to the 14th day after the insult.

Animals↗
PubMed1991

Effects of eye-enucleation on substance P-immunoreactive fibers of some retinorecipient nuclei of the rat in relation to their origin from the superior colliculus.

We have previously shown that retinal deafferentation causes a decrease in immunoreactive dendrites of substance P-positive neurons of the superficial superior colliculus of the rat. Since some retinorecipient thalamic and pretectal nuclei are putative targets for substance P-containing cells of the superior colliculus, the present study attempted to ascertain whether substance P-immunoreactive fibers in these nuclei are also affected by retinal denervation. We found that unilateral eye removal produced a progressive increase in fibrous substance P immunoreactivity in the nucleus of the optic tract, lateral posterior nucleus, and lateral geniculate nucleus of the side contralateral to the enucleation. On the other hand, unilateral lesions to the superficial layers of the superior colliculus produced a dramatic reduction in substance P immunoreactivity in the ipsilateral nucleus of the optic tract, lateral posterior nucleus, and dorsal and ventral lateral geniculate nuclei. In bilaterally enucleated animals, unilateral lesion to the superior colliculus produced, as expected, loss of immunoreactive fibers only in the lateral posterior nucleus and the retinorecipient nuclei ipsilateral to the lesion. These results suggest that transneuronal changes in the distribution of substance P in collicular neurons observed after enucleation could be reflected in their projections to the other primary visual centers and to the lateral posterior nucleus.

Animals↗
PubMed1991

Somato-, branchio- and viscero-motor neurons contain glutaminase-like immunoreactivity.

Immunocytochemistry combined with a fluorescent dye tracer method revealed that somatic, branchial and visceral motoneurons in the brainstem and spinal cord of the rat contain phosphate-activated glutaminase (PAG). An excitatory neurotransmitter glutamate is synthesized mainly through this enzyme. Among these motoneurons, neurons in the dorsal motor nucleus of the vagus nerve (dmnX), autonomic preganglionic neurons in the spinal cord and urethral sphincter motoneurons (DL) were most intensely immunostained. PAG is co-expressed with choline acetyltransferase, calcitonin gene-related peptide or galanin in these neurons. These findings, together with the findings that motor endplates in urethral sphincter muscle contain PAG and PAG-like immunostaining in dmnX motoneurons was decreased after axotomy, suggest that glutamate is a co-transmitter of acetylcholine in motoneurons. Brainstem motoneurons were moderately stained, while somatic motoneurons in the spinal cord other than DL, showed very weak staining for PAG. However, they showed intense PAG-like immunoreactivity at their premature stage, suggesting that glutamate has some effects on the maturation of these neurons. A variety of functional roles of glutamate in motoneurons is discussed.

Animals↗
PubMed1990

Calbindin D28k-containing splanchnic and cutaneous dorsal root ganglion neurons of the rat.

Calbindin D28k (CaBP)-containing splanchnic and cutaneous sensory neurons in the rat dorsal root ganglia (DRGs) were investigated immunocytochemically in combination with a fluorescent dye tracer (Fluoro gold). About 15% of the DRG neurons at Th9-10 levels showed CaBP-like immunoreactivity. Eighty-four % of the splanchnic sensory neurons were immunoreactive to CaBP, while only 3% of the cutaneous sensory neurons were. The diameters of the splanchnic and cutaneous sensory neurons containing CaBP were 23.4 +/- 6.3 microns and 38.4 +/- 8.8 microns, respectively. Splanchnic sensory neurons containing CaBP were sensitive to capsaicin while cutaneous ones were not. These findings suggest that CaBP-containing splanchnic and cutaneous sensory neurons constitute different subgroups among the DRG neurons at the lower thoracic level.

Animals↗
PubMed1990

Substance P and enkephalins in the superficial layers of the rat superior colliculus: differential plastic effects of retinal deafferentation.

In this work we studied the effects of unilateral eye enucleation on the contents and distribution of leu-enkephalin-, met-enkephalin-arg6-gly7-leu8-, and substance-P-like immunoreactivities (L-ENK-I, ENK-8-I, and SP-I, respectively) in the superficial layers of the rat superior colliculus (SC) by means of the unlabelled antibody peroxidase-antiperoxidase method. In the normal rat only a few L-ENK-I neurons appear dispersed in the stratum griseum superficiale. No immunostained somata appear in the stratum opticum. The most striking effect of unilateral enucleation was the dramatic appearance of a laminarly distributed population of L-ENK-I and/or ENK-8-I neurons in the dorsal stratum opticum of the SC contralateral to the enucleated side. This population of immunoreactive cells was observed with all the survival times examined in the present study (3, 7, 15, and 30 days) and was always accompanied by an increase in the immunostaining of L-ENK-I and/or ENK-8-I fibers in the contralateral stratum griseum superficiale. Enucleation also produced a decrease in the immunostaining of SP-I dendrites that only became obvious 15 days after enucleation. However, the number of SP-I somata or terminal-like immunoreactive structures showed no detectable changes. These results show that retinal deafferentation of the superficial layers of the rat SC has different effects on some immunohistochemically distinguishable neuronal subgroups in the SC, suggesting different functional or trophic relationships of the retinal input to these groups of neurons.

Afferent Pathways↗
PubMed1990

Fine structure of noradrenergic terminals and their synapses in the rat spinal dorsal horn: an immunohistochemical study.

Noradrenergic fibers in the spinal dorsal horn originate from neurons in the A5-7 cell groups, and may participate in the modulation of pain. Here we studied the fine structure of noradrenergic terminals in the rat by immunohistochemistry using antiserum against dopamine-beta-hydroxylase (DBH). We also investigated the relationship between such terminals and primary afferent terminals. DBH-like immunoreactive terminals were found in lamina I and the outer layer of lamina II of the dorsal horn and they contained many clear round vesicles and some large granular vesicles. More than half of these terminals made synaptic contact with other neuronal elements with membrane specialization. Most of the postsynaptic structures of these terminals were small dendrites (69%); 28% were spines, and no synaptic contact was made with primary afferent terminals. These findings suggest that noradrenaline acts on the spinal dorsal horn neurons postsynaptically mainly via a direct synaptic mechanism.

Animals↗
PubMed1990

Histamine application to the nasal mucosa induces release of calcitonin gene-related peptide and substance P from peripheral terminals of trigeminal ganglion: a morphological study in the guinea pig.

Short-term effects of application of histamine to the nasal mucosa on trigeminal ganglion neurons containing calcitonin gene-related peptide (CGRP) and substance P (SP) were examined in guinea pig. Immunoreactivities to CGRP and SP in these neurons were decreased 30 min after the histamine application. The decreases were most marked at 1-3 h after application, after which the immunoreactivities began to increase, reaching the base line by 6 h after the application. The immunoreactivities to CGRP and SP in the nerve endings of nasal mucosa were not decreased. The expression of mRNAs for both peptides in the soma of trigeminal neurons was unchanged. The histamine application to the nasal mucosa may cause release of CGRP and SP from terminals of peripheral processes of trigeminal ganglion neurons, and enhance axonal transport of these peptides, but does not affect their biosynthesis in the soma of trigeminal ganglion neurons.

Animals↗
PubMed1990

Peptidergic granule cell populations in the rat main and accessory olfactory bulb.

The distribution and incidence of substance P (SP)- and Met-enkephalin-Arg6-Gly7-Leu8 (ENK-8)-like immunoreactive granule cells in the main and accessory olfactory bulbs of male rats was studied immunohistochemically. In the granule cell layer of the main olfactory bulb, numerous ENK-8-like immunoreactive granule cells were observed but SP-like immunoreactive ones were rare (less than 1%). On the other hand, in the granule cell layer of the accessory olfactory bulb, both SP-like immunoreactive and ENK-8-like immunoreactive granule cells were numerous. 15-20% of these neurons contained both the peptides.

Animals↗
PubMed1990

Met5-enkephalin-Arg6-Gly7-Leu8-like immunoreactivity in the pelvic ganglion of the male rat: a light and electron microscopic study.

By using both light and electron microscopic immunocytochemical methods, Met5-Enkephalin-Arg6-Gly7-Leu8 (MEAGL)-like immunoreactive structures were detected in the pelvic ganglion of male rats. Denervation studies were carried out to determine the origin of these immunoreactive fibers and the projection of immunoreactive neurons within the pelvic ganglion. MEAGL-like immunoreactivity was found in numerous axon boutons, some small, intensely fluorescent (SIF) cells, and a few principal ganglion neurons. Most of the immunoreactive nerve fibers formed pericellular plexuses surrounding the ganglion cells. In addition, there were a few scattered varicose fibers. These fiber plexuses could be classified into two types: type I (approximately 90% of fibers), which consisted of 80-120 small boutons that synapsed on either the dendrites (80% of cases) or somata (20% of cases) of principal neurons; and type II (approximately 10% of fibers), which consisted of 20-40 larger boutons that formed axodendritic synapses exclusively. After transection of the hypogastric and pelvic nerves, virtually all of the pericellular fiber plexuses disappeared, whereas the scattered varicose fibers remained. According to their ultrastructure, these remaining fibers were considered to arise from SIF cells. Following the injection of Fast Blue into the bladder wall, some of the MEAGL-like immunoreactive principal neurons were retrogradely labeled. The results of this study indicate that there are two origins for the MEAGL-like immunoreactive fibers detected in the pelvic ganglion: most arise from preganglionic neurons in the spinal cord, and a small proportion may originate from intraganglionic MEAGL-like immunoreactive SIF cells or principal neurons. Some MEAGL-like immunoreactive principal neurons may project to the urinary bladder.

Animals↗
PubMed1990

Co-expression of alpha-CGRP and beta-CGRP mRNAs in the rat dorsal root ganglion cells.

We examined the expression of alpha-calcitonin gene-related peptide (alpha-CGRP) and beta-CGRP mRNAs in the rat dorsal root ganglion (DRG) using in situ hybridization histochemistry with oligonucleotide probes. Analysis of autoradiograms showed that alpha-CGRP mRNA labeled 36.4% of all DRG neurons and beta-CGRP mRNA labeled 30.8%. Small and medium-sized neurons expressed both types of mRNA, but large neurons showed a predominance of alpha-CGRP mRNA expression. The colocalization of alpha-CGRP and beta-CGRP mRNAs was shown at a cellular level in consecutive DRG sections. Thus, we demonstrated that alpha-CGRP and beta-CGRP were distributed differently in the DRG neurons, although genes coding for these neuropeptides coexist in the small or medium-sized neurons.

Animals↗