1987 Fiscal Year Final Research Report Summary
Synaptic Inputs to Neurosecretory Neurons
| Project/Area Number |
61480482
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
神経解剖学
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| Research Institution | Showa University |
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Principal Investigator |
NAKAI Yasumitsu Showa University School of Medicine, Professor, 医学部, 教授 (60053807)
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| Co-Investigator(Kenkyū-buntansha) |
SHIODA Seiji Showa University School of Medicine, Assistant Professor, 医学部, 講師 (80102375)
OCHIAI Hidehiko Showa University School of Medicine, Assistant Professor, 医学部, 講師 (40053954)
NAITO Nobuko Showa University School of Medicine, Assistant Professor, 医学部, 講師 (30053903)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Peptide neurons / Aminergic innervation / GABAergic innervation / Peptidergic innervation / ラット視床下部 |
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| Research Abstract |
To examine synaptic inputs to neurosecretory neurons in the rat hypothalamus at the electron microscopic level, some double immunolabeling techniques and a combined technique of immunocytochemistry and autoradiography after 3H-noradrenaline (^3H-NA) or 5-hydroxydopamine (5-OHDA) labeling in the same tissue section have been used. Concerning the innervation of neurohypophyseal hormone-containing neurons, peroxidase-antiperoxidase (PAP) labeled tyrosine hydroxylase, GABA or serotonin immunoreactive terminals making synaptic contacts with colloidal gold-labeled vasopressin or neurophysin-II immunoreactive neurons were found in the paraventricular and supraoptic nuclei (PVN, SON) of the rat hypothalamus. Serotonin or GABA immunoreactive terminals were found to make synaptic contacts with oxytocin or neurophysin I immunoreactive neurons in the PVN and SON. These findings suggest that the secretion of vasopressin- or oxytocin-containing neurons may be regulated via synapses by catecholaminergic, GABAergic or serotonergic neurons. As to the innervation of hypothalamic hormone-containing neurons, catecholamine terminals showing selective uptake of ^3H-NA or 5-OHDA were found to make synaptic contacts with LHRH immunoreactive neurons in the medial preoptic area, with CRH immunoreactive heurons in the PVN and with GRH immunoreactive neurons in the arcuate nucleus of the rat hypothalamus. These provide morphological evidences for catecholaminergic control of the release of LHRH, CRH or GRH, at the hypothalamic level. Furthermore, colloidal gold-labeled TRH immunoreative terminals were found to make synaptic contact with PAP-lebeled GEH immunoreactive neurons in the arcuate nucleus. From this finding, TRH-containing neurons may be considered to innervate GRH secretion or to have some other functions via synapses in the hypothalamic arcuate nucleus of the rat.
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