Objective To explore the excitatory effect of the sensory cortex through somatic electroacupuncture(EA) stimulation at Taichong(LR3). Methods Ten healthy volunteer men ranging in age from 20 to 50 years were enrolled in this study. EA(2 Hz

a tolerable strength) was applied to the left LR3. Before and after EA

the somatosensory evoked potential(SEP) from the Cz' area of the scalp was recorded by electrical stimulation of the bilateral dorsal penile nerves and the indentation behind the medial malleolus of the foot

termed as the pudendal SEP(PSEP) and lower extremity SEP(LSEP)

respectively.Results The amplitude of the left LSEP induced by stimulation of the left medial malleolus was significantly increased after EA(P < 0.05)

but there were no significant changes in the latency of LSEP and PSEP

and the amplitude of right LSEP evoked by stimulation of the left medial malleolus

and that of the PSEP. Conclusion EA at LR3 increases the excitability of the contralateral cerebral sensory cortex(lower extremity area)

but has no effect on the adjacent sensory cortex(genital area).