视前区微量注射吗啡对大鼠丘脑束旁核痛反应神经元电活动的影响

本实验观察了视前区(POA)内微量注入阿片样物质对丘脑束旁核(Pf)痛反应神经元电活动影响。结果如下:(1)POA 内微量注射高浓度吗啡(10μg/μl)能显著抑制 Pf 内大部分(20/26)痛兴奋神经元(PEN)的痛诱发放电,其中3个神经元注药后对伤害性刺激转变成抑制反应;POA 内微量注射低浓度吗啡(1μg/μl)也显著抑制 Pf 内大部分(19/23)PEN 的痛诱发放电。(2) POA 内微量注射两种浓度的吗啡,均使大多数痛抑制神经元(PIN,共27/33)的完全抑制时程缩短。上述结果提示,POA 内阿片样物质对 Pf 内痛反应神经元的电活动可能具有抑制作用。

THE INFLUENCES OF MORPHINE MICROINJECTED INTO PREOPTIC AREA ON ELECTRIC ACTIVITIES OF PAIN RESPONSE NEURONS IN PARAFASCICULAR NUCLEUS OF THALAMUS IN RAT

We have observed the influences of opioid-like substances in preoptic area (POA) on the electric activities of pain response neurons in parafascicular nucleus of thalamus (Pf). The results were as follows: 1. Morphine 10 micrograms/microliters or 1 micrograms/microliters microinjected into POA could remarkably inhibit the pain discharges of most (20/26, 19/23 respectively) pain excitatory neurons (PEN) in Pf. The frequency of evoked discharges was decreased nd the duration was shortened. After injecting 10 micrograms/microliters morphine, three neurons showed inhibitory responses to noxious stimuli. 2. Morphine of the two doses could shorten the complete inhibitory period of pain inhibitory neurons (PIN, 23/33). These results suggest that the opioid-like substances in POA might have an inhibitory effects on pain response neurons in Pf.