毁损大鼠SmI对丘脑Pf神经元针刺镇痛效应的影响及微电泳导入ACh的效应

Influence of SmI Lesion on Acupuncture-Induced Analgesia in Thalamic Pf Neurons and Effects of Iontophoretic Ach on Their Nociceptive Responses

用多管微电极细胞外记录及微电泳技术，观察到：毁损大鼠皮层SmI后，电针穴位对丘脑束旁核（Pf）神经无伤害性反应的抑制作用被减弱；微电泳导入ACh能抑制SmI毁损大鼠Pf神经元的伤害性反应，其作用与SmI完整时电针对其伤害性反应的抑制效应相似。结果表明，ACh是参与皮层对丘脑Pf神经元针刺镇痛下行调节的神经递质之一。

This study aimed to investigate the role of ACh in SmI emanating descending modulation of thalamic Pf neurons in acupuncture analgesia.Multi-micropipettes were used for both extracellularly recording responses of thalamic Pf neurons to noxious stimulation of the plantar area and drug application in rats.It was found that (1) lesion of SmI obviously attenuated the inhibitory effect of EA applied at 'Zusanli'and 'Huantiao'points on nociceptive responses in Pfneurons; (2) after lesion of Sml iontophoretic application of ACh markedly suppressed the nociceptive responses of Pf neurons, which was significantly different from the effect of iontophoretic NaCl (as the control) showing no influence on them; (3)the inhibition induced by iontophoretic ACh applied in the rats with lesion of SmI was similar to that produced by EA applied in those with SmI intact.It is indicated that EA can activate SmI to release ACh to exert descending modulation, in which ACh is involved in SmI originating descending regulation of Pf neurons in acupuncture analgesia