Mason R, Brooks A
Department of Physiology, Medical School, Queen's Medical Centre, Nottingham, U.K.
Neurosci Lett. 1988 Dec 19;95(1-3):296-301. doi: 10.1016/0304-3940(88)90674-x.
Several studies have implicated the suprachiasmatic nuclei (SCN) as a target for the action of melatonin in its regulation of seasonal and circadian behaviour. Single-unit activity from the SCN and adjacent paraventricular area and anterior hypothalamus was recorded using the in vitro rat hypothalamic slice preparation. Neurones were tested for responses to iontophoresed or pressure ejected melatonin (n = 62) and serotonin (5-HT, n = 80). The majority (n = 24-26) of melatonin-sensitive SCN neurones were inhibited by melatonin in a dose-dependent manner during the latter portion of the projected light phase of the circadian light-dark cycle. A putative melatonin antagonist, N-acetyltryptamine, exhibited concentration dependent mixed agonist-antagonist effects on melatonin-evoked responses.
多项研究表明，视交叉上核（SCN）是褪黑素调节季节性和昼夜节律行为作用的靶点。利用体外大鼠下丘脑切片制备技术，记录了SCN以及相邻室旁区域和下丘脑前部的单单位活动。测试了神经元对离子导入或压力喷射的褪黑素（n = 62）和5-羟色胺（5-HT，n = 80）的反应。在昼夜明暗周期预计的光照期后半段，大多数（n = 24 - 26）对褪黑素敏感的SCN神经元受到褪黑素的剂量依赖性抑制。一种假定的褪黑素拮抗剂N-乙酰色胺对褪黑素诱发的反应表现出浓度依赖性的混合激动剂-拮抗剂效应。
