【摘要】 目的 本实验观察大鼠侧脑室内加入外源性乙酰胆碱(ACh)后，蓝斑核(Locus ceruleus，LC)痛反应神经元的电变化，以及M受体激动剂毛果芸香碱(Pilocarpine)的激动效应，进一步研究ACh和LC在痛觉调制中的作用及其相互关系。方法 以电脉冲刺激右侧坐骨神经作为伤害性痛刺激，用玻璃微电极细胞外记录痛反应神经元放电的变化。结果 1)侧脑室注入ACh能够使正常大鼠LC中痛兴奋神经元(PEN)痛诱发放电频率增加、潜伏期缩短，痛抑制神经元(PIN)痛诱发放电频率减少，诱发放电完全抑制时程延长，而后逐渐恢复；2)侧脑室注入毛果芸香碱能够产生与ACh相似的效应。结论 外源性ACh可使正常大鼠LC中痛反应神经元对伤害性刺激的反应增强，表现为致痛效应；M受体激动剂毛果芸香碱可使正常大鼠LC中痛反应神经元对伤害性刺激的反应增强，与ACh产生相似的效应；揭示了ACh的这种致痛作用主要是通过M受体介导的。

    【关键词】 蓝斑核 痛兴奋神经元 痛抑制神经元 乙酰胆碱 毛果芸香碱

    Pilocarpine on Electric Activities of Pain-related Neuron in Locus Cerul of Rats

    ShenYunhong,et al.

    (Department of Physiology，Harbin Medical University，Heilongjiang Province 150081)

    【Abstract】 Objective The experiment studied the effects of acetylcholine (ACh) and M-receptor agonist pilocarpine on the electric activities of the pain-related neurons in the locus ceruleus (LC) of normal rats,in order to further study the role and the interaction of ACh and LC in the modulation in the algetic sense.Methods Trains of the electric impulses applied to the right sciatic nerve were used as noxious stimuli,the discharge of the pain-related neurons were recorded by the glass microelectrodes.Results 1)The intracerebroventricular injection of ACh increased the pain-evoked discharge frequency and shortened the latency of PEN,decreased the pain-evoked discharge frequency and prolongated of the inhibitory duration of PIN in LC of the normal rats.2)The intracerebroventricular injection of M-receptor agonist pilocarpine was similar to the effects of ACh.Conclusions The exogenous ACh could enhanced the response of pain-related neuron in LC of normal rats to noxious stimulation,expressing as painful effects.The effect of M-receptor agonist pilocarpine was similar to ACh.The painful effect of ACh achieved by the M-receptor. ......