【摘要】 本实验用细胞外记录法,观察大鼠外侧隔核(LS)微量注射促甲状腺素释放激素(TRH)对丘脑束旁核痛兴奋神经元(PEN)放电的影响。结果如下:(1)LS注射TRH对束旁核PEN痛放电产生明显的抑制效应;TRH的最大抑制效应及持续时间与TRH剂量(1,2.5,5μg/1μl)的对数呈正线性相关;(2)预先 LS 注射纳洛酮(3μg/1 μl)不能改变TRH抑制柬旁核PEN痛放电效应;(3)预先LS注射阿托品(5μg/lμl)阻断了TRH对束旁核PEN痛放电的抑制效应。结果表明:LS是TRH参与镇痛的一个有效的作用部位。LS胆碱能M受体可能参与了TRH的抑制PEN痛放电效应,而TRH的抑制效应未涉及阿片受体。更多还原

【Abstract】 Thyrotropin-releasing hormone( TRH) has central analgesic effect, but its mechanism is unclear. Lateral septal nucleus (LS) participating in pain modulation and has dense TRH-con-taining fibers and TRH receptors. In order to examine the antinociceptive effect of TRH, the effect of microinjection of TRH into LS on discharges of pain-excitation neurons(PEN) in nucleus parafascicularis of rat thalamus was investigated.The results are as follows: (1) Injection of TRH into LS induced an inhibitory effect on the pain discharges of PEN in nucleus parafascicularis. The maximal inhibition rate and inhibition duration were linearly dependent on the log doses of TRH (1, 2.5, 5μg/ 1μl). (2) The inhibitory effect of TRH is prevented by pretreatment with M-receptor antagonist arropine (5μg / 1μl) injected into LS, but not by opioid receptor antagonist naloxone (3μg / 1μl).The results suggest that LS is an effective area for the antinociceptive effect of TRH and that inhibitory effect of TRH appears to be mediated by M-receptors, but not by opioid receptors in LS.更多还原