我们曾设想大脑皮层参与疼痛和针刺镇痛过程的调节机制除通过各种信息在皮层内发生整合作用外

尚有可能通过某些信息(包括针刺信息)激活皮层后产生的下行性作用。最近我们的工作表明以γ-氨基丁酸(GABA)滤纸施加于猫的大脑皮层体感Ⅱ区(SⅡ)后

电针对丘脑束旁核(Pf)伤害性反应的抑制效应被取消。在另一批实验中以2％利多卡因滤细施加于猫的SⅡ后

电针可取消丘脑中央中核(CM)的伤害性反应。这些结果提示SⅡ可能参与针刺镇痛的下行性调节。国内有资料报道刺激家兔大脑皮层体感Ⅰ区(SⅠ)可影响丘脑Pf及In our laboratory it was reported when GABA or 2% Lidocarine was placed on SII topically the acupuncture effect on nociceptive response of pf or CM neuron was abolished or decreased. This result suggested that the corticofugal modulation from SII may play a role in acupuncture ana- lgesia. In order to get further information about this problem. In the pre- sent study the effect of acupuncture on nociceptive response of pf neuro- ns which were observed on the background of SII glutaminized topically was investigated. The experiment was carried out on cats. The methods was as same as the previous work except glutamine was placed on the SII topically. The result showed on the background of SII glutaminized topically the discharge of majority of pf neurons induced by noxious stimlation might be inhibited by electroacupuncture "Zusanli" "Huantiao". The duration of acupuncture effect maintained for 10 minites. This inhibitory duration were longer than that of saline control group

but there were no statistical signi- ficance as compared in both. It was demonstrated from this experiment at least there was a difference between GABA and glutamine. The former exe- rted a decrease effect on acupuncture analgesia

while the later just exerted an opposite effect on it. Thus it may be considered that corticofugal infl- uence activated by acupuncture is involved in the modulation of nociceptive response of pf neurons.