电刺激大白鼠下丘脑外侧区对痛阈的影响

本文采用辐射热甩尾反应为痛指标,观察了电刺激大鼠下丘脑外侧区(LHA)对痛阈的影响和腹腔注射纳洛酮对LHA镇痛效应的影响。结果表阴,电刺激LHA后,动物的痛阈平均提高了52.2%。注射纳洛酮后,LHA的镇痛效应显著下降。LNA的镇痛效应远不及电针镇痛效应强。

The effect of electrical stimulation of the lateral hypothalamus on the pain threshold of rat

Although numerous workers have reported that pain responses of animals can be significantly inhibited by the electrical stimulation of the lateral hypothalamus ( LHA ) , a few workers have reported that stimulation of LHA produced iittie or no analgesic effect at all. Again, a quantitative analyses of the analgesic action of LHA elicited by electrical stimulation is also quite necessary. Apparently, it is interesting to know whether the analgesic function of LHA can be antagonized by naloxone. In the present report the above mentioned points were studied and experiments were carried out on rats by chronic means: observing the effect of electrical stimulation of LHA on the tailflick responses to radiant heat. The results showed : (1) the pain threshold of tail-flick responses was increased 52.2% after stimulation of LHA. Quantitatively, the analgesic effect of stimulation of LHA is less effective than that of electro-acupuncture analgesia; (2)that the average rate of the pain threshold increased 62.6% when LHA was stimulated before injection of naloxone in comprison with 10.7% after naloxone injection, indicates that endogenous opiate-like substances may be involved in the analgesic process of LHA. Possible mechanisms of the analgesic action of LHA as well as the probable factors that may influence the present results were discussed.