杏仁核在针刺镇痛中作用——动物实验报告

<正> 文献记载,杏仁核不仅同下丘脑,中脑网状结构,中央灰质,尾核头部有密切的纤维联系,也与内侧丘脑,后丘脑有一定的纤维联系.关于杏仁核同疼痛的关系,国内外已有一些报导.如:杏仁核含有丰富的内啡胀和吗啡受体,向杏仁核内微量注射吗啡和5-羟色胺可以提高动物的痛阈,抑制动物的攻击性行为,电刺激杏仁核可以提高动物的痛阈.可见,杏仁核同痛反应有一定的关系.为了探讨杏仁核及

ROLE OF AMYGDALA IN ACUPUNCTURE ANALGESIA——EXPERIMENT REPORT IN ANIMALS

The role of amygdala in acupuncture analgesia was studied in rabbitswith chronically implanted electrodes in the amygdala.Rabbits weighing1.5-2.Skilogams were used for this study.By means of the stereotaxicalapparatus two pairs of electrodes were implanted bilaterally into the amygd-ala accotding to Sawyer's atlas.Three days after operation all experimentswere carried out.Iontophoresis of potassium ion to the skin of rabbit's earserved as the noxious stimulation.Minimal electric current(mA)requiredto produce the defence reaction of the head and forelimb was taken as thepain threshold.Control pain threshold was determined before experiment.The parameters of electric stimulation were 150-250mA,5-10Hz,0.5mSec.At first,amygdala was stimulated unilaterally during one minute,and thennoxious stimulation was given.Both stimulations were stopped at once whenthe reaction of the pain presented.In the 14 rabbits an increase of 25.55%(P<0.01)in the pain thresholdoccured when the amygdala was stimulated unilaterally.The control group had no effect on the pain threshold(P>0.05).Whe pain threshold had risen strikingly during amygdala stimulation,naloxone(0.4mg/kg)was administre.The result was that the raised painthreshold fell in 13 rabbits,showing reversal of analgesic effect in variousdegrees.In the control experiment,7 rabbits were injected with normalaqueous solution.No noticeable change of the analgesic effect was found.The difference of two experiments was statistically significant(P<0.05).The result suggest that the raised pain threshold can be reversed by nalox-one.In 11 rabbits,there was,befor lession of the bilateral amygdala,artincrease of 41.0%(P<0.01)in the pain threshold following electro-acu-puncture.After lession only an increase of 25.75% was produced by electro-acupuncture.The difference was statistically significant(P<0.05),sugges-ting a marked decrease of the effect of acupuncture analgesia after the am-ygdala was damaged bilaterally.