远节段电针对屈肌反射电位及背根电位的影响

本工作观察了电针清醒、整体大鼠同侧内关穴对后肢屈肌反射电位(FRP)和相应的背根电位(DRP)的影响。以串刺激(3个脉冲,间隔5ms,波宽0.5ms)分级刺激腓肠神经(皮神经),在hamstring神经干上(一组支配后肢屈肌群的神经)和L_5背根上分别诱发出适当大小的C-FRP和C-DRP(约为最大值的70%～80%),以低频低强(4Hz,1～3V)、低频高强(4Hz,20～40V)电针同侧内关穴,持续5min停针后观察到C-FRP和C-DRP的值均降低;C-DRP受抑程度较C-FRP为轻且恢复也较快,二者的潜伏期均不变。电针内关穴时A—FRP和A—DRP没有明显作用。实验结果提示电针同侧内关穴可引起后肢镇痛,且镇痛中可能有中枢的突触前抑制机制参与。

THE EFFECT OF REMOTE SEGMENTAL ELECTRO-ACUPUNCTURE ON THE FLEXION REFLEX POTENTIAL AND THE DORSAL ROOT POTENTIAL

Deseription was given of the effect of electric acupuncture of Neiguan point on the flexion reflex potential (FRP) of the hindlimbs and the dorsal root potential (DRP). On the intact and awake rats, the graded train stimulation (three pulses, 5ms interval, 0.5ms duration) was given to the sural nerve (a pure cutancous n(?), the C-FRP and C-DRP with their proper amplitudes (70～80% maximum) were obtained on the hamstring nerve (a group of nerves innervating the hindlimb flexors) and L5 dorsal root respectively. Then the electric acupuncture with low freqency and low intensity (4Hz, 1～3V)and low freqency and high intensity ( 4Hz, 20～40V), lasting 5 minutes, was given to the ipsilateral Neiguan point. After acupuncture, the amplitudes of both C-FRP and C-DRP decreased without change of their latebcues. The former one declined heavier and recovered slower than the latter one did. The A-FRP and A-DRP were not affected. Te result of the experiment suggests that the ipsilatcral Neiguan point cletric acupuncture can induce hindlimb's analgesia, the presynaptic inhibition might be involved in the mechanism of such analgesia.