Extensive researches of mesolimbic ventral tegmental area(VTA) in drug addiction have been conducted. Recently, some evidence showed that VTA is involved in morphine analgesia. However, no data show whether the mesolimbic DA pathways involve the mechanism of electroacupuncture (EA) analgesia. In this study, the effect of bilateral 6 hydroxdopmine(with desipramine)lesions of VTA on analgesi a produced by EA with different frequencies (2 Hz and 100 Hz) was examined with tail flick tests in rats. These lesions depleted dopamine. The results showed th at EA with different frequencies produced the same degree of analgesia both in s ham lesioned and lesioned rats(P>0.05) though there was some decrease of tail flick latency(TFL) in the lesioned rats,while it appeared an increase o f TFL in lesioned rats after EA and possessed the significant difference from sh am lesioned rats( P<0.05). Further study should adopt different pain m odels to explore the effect of mesolimbic DA systems in EA analgesia.
