Gillet G, Ammor S, Fillion G
J Neurochem. 1985 Dec;45(6):1687-91. doi: 10.1111/j.1471-4159.1985.tb10523.x.
Rat brain striatum slices were incubated with [3H]choline, perfused with a physiological buffer, and stimulated by perfusion with a K+-enriched buffer for 2 min. The tritium overflow evoked by K+ was decreased by 5-hydroxytryptamine (serotonin, 5-HT) (maximal inhibition 10(-6) M). This effect of 5-HT was mimicked by several agonists (5-methoxytryptamine, N,N-dimethyl-tryptamine, bufotenin) and blocked by serotonergic antagonists (methiothepin, methysergide, cinanserin) but not by haloperidol; methiothepin and methysergide alone slightly increased the K+-evoked overflow of tritium (3H). Inhibition of the tritium release by 5-HT was not suppressed in the presence of tetrodotoxin (TTX) (10(-6) M). These results suggest that 5-HT tonically inhibits acetylcholine (ACh) release from striatal cholinergic neurons by acting on a presynaptic receptor localized on cholinergic terminals.
将大鼠脑纹状体切片与[3H]胆碱一起孵育，用生理缓冲液灌注，并用富含钾的缓冲液灌注刺激2分钟。5-羟色胺（血清素，5-HT）可降低钾引起的氚溢出（最大抑制浓度为10^(-6) M）。几种激动剂（5-甲氧基色胺、N,N-二甲基色胺、蟾毒色胺）可模拟5-HT的这种作用，而5-羟色胺能拮抗剂（甲硫哒嗪、麦角酰二乙胺、辛那色林）可阻断这种作用，但氟哌啶醇不能；单独使用甲硫哒嗪和麦角酰二乙胺会轻微增加钾引起的氚溢出（3H）。在存在河豚毒素（TTX）（10^(-6) M）的情况下，5-HT对氚释放的抑制作用并未受到抑制。这些结果表明，5-HT通过作用于胆碱能终末上的突触前受体，对纹状体胆碱能神经元的乙酰胆碱（ACh）释放产生持续性抑制作用。
