This study aimed to investigate whether the sensorimotor area I (SmI) emanating descending modulation of thalamic Pf neurons in acupuncture analgesia is related to activation of SmI neurons by electroacupuncture (EA). In the present experiments the effect of EA on spontaneous discharges of neurons in SmI was observed in rats. It was found that EA made the spontaneous discharges of SmI neurons obviously increased(p < 0. 05). It is indicated that EA can activate SmI neurons
by which SmI is involved in the descending modulation of Pf neurons in acupuncture analgesia.