八肽胆囊收缩素对抗电针对大鼠束旁核痛反应神经元电活动和甩尾痛阈的同时影响

SIMULTANEOUS ANTAGONISM TO EFFECTS OF ELECTROACUPUNCTURE ON ELECTRIC ACTIVITIES OF PAIN-RELATED NEURON IN NUCLEUS PARAFASCICULARIS OF THALAMUS AND TALL FLICK LATENCY IN RATS BY CHOLECYSTOKININ OCTAPEPTIDE

摘要:

已知八肽胆囊收缩素（CCK－8）能对抗阿片物质的镇痛作用。本实验首次以大鼠丘脑束旁核中痛兴奋神经元（PEN）、或痛抑制神经元（PIN）放电及辐射热甩尾三者为指标，同时观察了脑室注射CCK－8对抗电针引起丘脑束旁核痛反应神经元放电和甩尾痛阈的影响。结果如下：（1）辐射热照尾可使PEN诱发放电频率增多或PIN诱发放电频率减少的同时发生甩尾反射，表现出疼痛反应。（2）电针双侧“足三里”15分钟，可以抑制PEN和加强PIN的电活动，同时使甩尾反射潜伏期（TFL）延长，呈现出镇痛效应。（3）脑室注射10gCCK－8能对抗电针引起的PEN放电抑制或PIN电活动加强及TFL延长的作用。上述结果证实，CCK－8的抗电针镇痛作用在中枢神经元放电和整体行为水平上是协同一致的。

Abstract:

Cholecystokinin octapeptme(CCK-8) has been shown to antagonise the analgesic effect of opioid subetunces. In the present study, the changny of boarge ratds of poin-excitatory neurons(PEN)and pein-inhibitory neurons(PIN)in nucleus peafascicularis(n. pf)of thalamus and tail-flick latency (TFL) caused by radinnt heat in rats were tuken as indices tostudy the antugonism of CCK-8 injected cerebtoventticularly to the effects of electroacupuncture(EA) on dforharges of pain-related neurons in n. pf of thalamus and pein threshold measured by tail flick latency. The results were as follows: (1)The radiant haeat focused on the tuil of rats caused an increase of the evoked discharge of PEN and a reduction of the evoked dischargeing of PIN and the induction of tuil-flick reflex simultuneously. (2)EA at bilateral "ZuSanLi" for 15 minutes resulted in an inhibition of the electric activity of PEN as well as a potentiation of the electtic activity of PIN and a prolongation of TPL, i. e., exhibiting the analgesic effect of EA. (3)The inhibitory effect of EA on the discharges of PEN and the potenttating effect of EA on the electric activities of PIN, and the prolonged effect of EA on TFL were antagonized by introcerebroventricular injection of long CCK- 8. The results demonstrated that antugonism of CCK-8 to analgesic effect of EA shows the coordinated and consistent activities on the levels of dtheharges of central neurons and the behavbor response.