1996 Fiscal Year Final Research Report Summary
Physiological significance of enzyme-activating substances in the neuroendocrine cells.
| Project/Area Number |
07670036
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Showa University |
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Principal Investigator |
NAKAI Yasumitsu School of Medicine, Department of Anatomy, Showa University, Professor, 医学部, 教授 (60053807)
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| Co-Investigator(Kenkyū-buntansha) |
OU Keihei School of Medicine, Department of Anatomy, Showa University, Assistant, 医学部, 助手 (10245821)
SHIODA Seiji School of Medicine, Department of Anatomy, Showa University, Assistant Professor, 医学部, 講師 (80102375)
OCHIAI Hidehiko School of Medicine, Department of Anatomy, Showa University, Associate Professor, 医学部, 助教授 (40053954)
NAITO Nobuko School of Medicine, Department of Anatomy, Showa University, Associate Professor, 医学部, 助教授 (30053903)
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| Project Period (FY) |
1995 – 1996
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| Keywords | Hypothalamus / Neurosecretory cells / PACAP neurons / Glutamate neurons / NOS neurons / Receptors / Synapses / Immunoelectron microscopy |
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| Research Abstract |
Ultrastructural localization of pituitary adenylate cyclase activating polypeptide (PACAP), nitric oxide synthase (NOS) and glutamate in the neuroendocrine cells of the rat hypothalamus were observed to examine their functional significances by electron microscopic immunohistochemistry.
PACAP-like immunoreactive axon terminals were found to make synapses with the vasopressin-like immunoreactive cell processes and cell bodies in the supraoptic nucleus of the rat hypothalamus using preembedding double immunostaining.
In situ hybidization revealed high-level expression of PACAP type 1 receptor (PACAP R-1) mRNA in the vasopressin-like immunoreactive neurons in the supraoptic nucleus of the rat hypothalamus.
We found the vasopressin-containing neurons in the supraoptic nucleus strongly expressed PACAP R-1 mRNA by combining immunohistichemical staining and in situ hybridization of the same tissue sections. These findings suggest that PACAP-containing neurons might regulate the secretion of vasopressin via PACAP type 1 receptor.
PACAP may have a physiological role in the release of vasopressin, as well as in induction of the expression of the gene for vasopressin via regulation of the cytosolic level of cAMP.
Concerning NOS-containing neurons in the dorsal raphe nucleus, the cytoarchitecture of the NOS-like immunoreactive neurons was similar to that of the serotonergic neurons. NOS-like immunoreactive axon terminals were found to make synapses with some unknown neurons.
In the rat hypothalmic periventricular nucleus, glutamatergic and GABAergic axon terminals formed synaptic contacts on the glutamate receptor subunit (NMDA-R1) immunoreactive endrites. These results suggest that NMDA-R1 containing neurons could be regulated by excitatory and inhibitory neurons.
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