电针对大鼠尾核痛兴奋、痛抑制神经元放电和甩尾反射的影响

EFFECTS OF ELECTROACUPUNCTURE ON THE FIRING OF PAIN EXCITATION AND PAIN INHIBITION NEURONS IN CAUDATE NUCLEUS AND THE TAIL FLUCK IN RATS

浅麻醉ｗｉｓｔａｒ大鼠２５只，用Ｇ－６８０５型治疗仪电针刺激双侧“足三里”。以辐射热照尾部作为伤害性刺激，将痛兴奋神经元（ＰＥＮ）诱发放电频率减少，痛抑制神经元（ＰＩＮ）诱发放电频率增加和甩尾反射潜伏期（ＴＦＬ）延长作为镇痛效应，观察电针刺激“足三里”对尾核中ＰＥＮ、ＰＩＮ及ＴＦＬ的影响。结果表明，电针刺激“足三里”，尾核中ＰＥＮ、ＰＩＮ放电及ＴＦＬ均显示镇痛效应；电针对ＰＥＮ、ＰＩＮ放电及ＴＦＬ的影响高峰均出现在电针后即刻；电针前ＰＥＮ放电频率增加、ＰＩＮ放电频率减少与甩尾反射（ＴＦ）相伴行。放电变化发生在ＴＦ之前，结束在ＴＦ之后，ＰＥＮ、ＰＩＮ放电变化与ＴＦＬ呈高度正相关。镇痛作用高峰期ＰＥＮ、ＰＩＮ放电变化仍在ＴＦ前，结束在ＴＦ之后，两者呈高度正相关。提示尾核中的ＰＥＮ、ＰＩＮ是痛觉调节中枢的一部分，可能参与对ＴＦ的调节。

The effects of electroacupuncture(EA)at bilateral“ZUSANLI”points on thenring of painexcitatiOn neurons(PEN)and pain inhibition neurons(PIN)and the tail flick latency(TFL)wereobserved simuItaneously in twenty-five lightly anesthetized Wistar rats.The radiant heat focusedon tail was used as noxious stimulation. The decrease in the firing rate of PEN and the increase infiring rate of PIN and the prolongation of TFL were regarded as antinociceptive effects.The re-sults showed that the firing of PEN and PIN and TFL indicated antinociceptive effects of EA,which were strongest immediatelv after EA.Before EA,the increase in firing rate of PEN and thedecrease in activities of PIN occurred before TF and stopped after TF,showing a strong correla-tion between TFL and the latency of the change in discharge of PEN and PIN.Immediately afterEA,the change in discharge of PEN and PIN occurred before TF and stopped after TF,so therewas a definite correlation between TFL and latency of the change in discharge too.The resultssuggest that the tail flick reflex may be modulated by the activities of both PEN and PIN incdudate nuclei.