[Effects of electroacupuncture at different points on nociceptive responses of the ventro-basal complex]

The purpose of the present study was to compare the effects of electro-acupuncture at different points on nociceptive responses of VB neurons. The experiments were carried out on rats (280-320g) anaesthetized with urethane (19/kg,i.p.). Single unit activities of VB neurons were extracellularly recorded by means of glass microelectrodes. Noxious stimulation was subcutaneously applied at the left ankle joint by inserting two stainless needles. The experiments were divided into three groups: EA. I, EA. II and EA. III. The corresponding points being selected for electroacupuncture in the above three groups were the left "Huantiao" (G30) point, the right "Huantiao" point and the left "Jianlian" (T14) point. The results showed that electroacupuncture at the points in the three groups all could inhibit the nociceptive responses of VB neurons, but electroacupuncture an the left "Huantiao" point (n = 11) was more effective than either at the right "Huantian" point (n = 9) or at the left "Jianliao" point (n = 10). There was a significant difference among the three groups. However, there was no significant difference between EA. II and EA. III. Thus, the results indicate that there is a relative specificity of points in acupuncture analgesia.