本实验室以往工作曾观察到

电解毁损大鼠一侧皮层体感区后

可削弱电针提高甩尾阈的作用。该结果提示

大脑皮层对脊髓水平痛反应有下行调节作用。但有工作报导

横断脊髓的大鼠

电针后甩尾阈同完整鼠相比

电针效应虽下降并达到统计学意义

但电针仍可使脊髓鼠的甩尾阈提高

只In this paper the effects of electroacupuncture on nociceptive responses were investigated after electrolytic lesion of unilateral somatosensory cortex on diffe-rent days. It was found that the tail flick latencies (TFL) e1icited by radiantheat was not obviously changed by EA (n=10

P>0.05) on the same day andthe next day after the somatosensosy cortex was injured

but the enhancementof TFL by EA was of statistical significance on the 7th day (n=9

p<0.05).These results indicate that the effect of EA analgesia was attenuated after lesionof the somatosensory cortex unilaterally. However

it could be recovered after aperiod of time. It is suggested that the somatosensory cortex is involved in thedescending modulation of nociceptive responses at the spinal level

although it maynot be the essential structure.