EFFECTS OF COEXISTING NEUROCHEMICALS ON THE RELEASE OF SEROTONIN FROM THE INTERMEDIATE AREA OF RAT THORACIC SPINAL-CORD

被引:3
作者
YANG, L [1 ]
HELKE, CJ [1 ]
机构
[1] UNIFORMED SERV UNIV HLTH SCI,GRAD PROGRAM NEUROSCI,BETHESDA,MD 20814
关键词
COEXISTENCE; 5-HT IN VITRO RELEASE; INTERMEDIOLATERAL CELL COLUMN; TACHYKININ RECEPTORS;
D O I
10.1002/syn.890210406
中图分类号
Q189 [神经科学];
学科分类号
071006 ;
摘要
Serotonin (5-HT), substance P (SP), neurokinin A (NKA), and thyrotropin-releasing hormone (TRH) coexist in the nerve terminals of the intermediolateral cell column (IML) of the thoracic spinal cord. The Ca2+-dependent release of 5-HT from the microdissected intermediate area (including the IML) of the rat thoracic spinal cord, and the 5-HT1B autoreceptor regulator of 5-HT release, were previously demonstrated. In this paper, the effects of SP, NKA, TRH, and/or their analogs on the release of [H-3]5-HT from the intermediate area were investigated using an in vitro superfusion system. Both SP (the endogenous ligand for neurokinin-1 (NK1) receptor) and an NK1 agonist (GR 73632) significantly increased the basal release of [H-3]5-HT. SP and GR 73632 did not change the K+-stimulated release of [H-3]5-HT. The effect of the NK1 agonist on the basal release of [H-3]5-HT was dose-dependent, was reduced by an NK1 antagonist (GR 82334), and was not dependent on extracellular Ca2+. Neither NKA, an NK2 agonist (GR 64349), nor a TRH analog (MK-771) altered the basal or stimulated release of [H-3]5-HT. These data suggest that basal release of 5-HT from the intermediate area of the rat thoracic spinal cord is regulated by SP (acting through an NK1 receptor), but not by NKA or TRH. These results provide evidence for the role of SP as a modulator of serotoninergic neurons in the intermediate area of the thoracic spinal cord, and may help to clarify the role of coexisting neurochemicals in the spinal regulation of the sympathetic nervous system. (C) 1995 Wiley-Liss, Inc.
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页码:319 / 323
页数:5
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