This proposal requests renewal of funding for study of the effect of electrical acupuncture (EA) on the perception of laboratory induced dental pain in man. We have shown that EA and transcutaneous electrical stimulation (TES) significantly reduce the ability of human subjects to perceive noxious dental sensory input, and we have measured this with both psychophysical methods and cortical evoked potentials. Our results suggest this effect is due partly to release of endogenous morphine-like substances during analgesic stimulation. Future work will further explore EA and TES dental analgesia phenomena and specify optimal parameters for pain control. We will develop measures of cortical evoked potentials to dental shock as a system of nonverbal pain assessments. We plan to further investigate the possible role of endogenic opiates in EA and TES analgesia, the possible interfering effects of anxiety on endogenic responses to EA and TES, and the possible role of endogenous opiate response in hypnotic analgesia.