针刺不同穴位对视网膜电图和皮层视觉诱发电位的影响

Effect of Electroacupuncture of Different Acupoints on Electroretinogram and Cerebral Visual Evoked Potentials in Healthy Subjects

目的:观察针刺不同穴位对健康成人视网膜电图(ERG)和视觉诱发电位(VEP)的影响,探讨经穴功能的相对特异性。方法:33名志愿者参与本实验。以直径为1 cm装有导电膏的圆盘形表面电极放置于眼眶下缘皮肤表面(测ERG),或放置于正中线右旁开5 cm、耳上5 cm的枕部皮肤表面(测VEP)。视觉刺激的闪光频率为1次/s,光源与眼距离50 cm。受试者静卧,给予20次闪光刺激,同时用叠加仪将20次ERG、VEP反应进行平均加算,获得1次叠加结果。按同法记录3～5次反应作为针前基础值。然后刺激穴位,待出现针感时连接电子刺激器,给予电脉冲刺激,频率0.5 Hz,波宽0.2 ms,电针10 min后记录3～5次ERG、VEP作为针时值。测试穴位分别为光明、内关、足三里,每穴测试时间至少相隔3 d。结果:电针刺激光明穴对ERGb波振幅、VEP P100振幅的影响较大,变化是双向的,而电针刺激内关穴和足三里穴对ERGb波的振幅和VEP P100振幅的影响比较小,其差异十分显著(P<0.01)。结论:电针胆经光明穴对ERG和VEP振幅的影响明显大于电针内关和足三里,提示不同穴位对ERG、VEP活动的影响具有相对的特异性。

Objective To observe the effect of electroacupuncture （EA） of different acupoints on electroretinegram （ERG） and cerebral visual evoked potentials （VEP） in healthy subjects so as to evaluate the relative specificity of the function of acupoints. Methods A total of 33 healthy adult volunteers were observed in the present study. The subject was asked to lie on a testing bed for a while, two disk electrodes were respectively fixed to the suborbital region and the occiput （the crossing point, 5 cm apart from the right median line of the head and 5 cm above the ear）, and the reference electrode was fixed to the medial side of the earlobe for recording ERG and cerebral VEP separately. The testing room was asked to keep faint light during the whole recording process. A flash stimulation （frequency 1 Hz） was applied to the subject＇s eye （with a distance of about 50 cm between the light source and the tested eye, and the other eye was covered by an eyepatch）. EA （0.5 Hz, 0.2 ms and 3--4 V） was applied to Guangming （GB 37）, Neiguan （PC 6） and Zusanli （ST 36） for 30 min respectively in different testing days （with the interval being 3 days at least）. ERG and cerebral VEP were recorded by using Polygraphy （RM-6200）. Results Following EA of Guangming （GB 37）, Neiguan （PC 6） and Zusanli （ST 36） ,the changing values （increase and decrease） of the amplitude of bwaves of ERGand P100 waves of cerebral VEP were （19.68± 12.61）% and （12.84± 14.08）%, （6.09± 14.06）% and （5.61 ±8.01 ）%, （2. 39± 3.52）% and （5.43 ± 8.22）%, respectively, while these ef b waves of ERG and Pva0 waves ef cerebral VEP of GB 37 were significantly bigger than those of PC 6 and ST 36 （P〈0.01）. Conclusion EA of Guangming （GB 37）can significantly change the amplitude of both ERG and cerebral VEP in volunteer subjects, which is markedly bigger than those of EA of Zusanli （ST 36） and Neiguan （PC 6）, suggesting a relative specificity of the effect of EA of different acupoints.