Modulation of the Sleep State–Dependent P50 Midlatency Auditory-Evoked Potential by Electric Stimulation of Acupuncture Points

Bray PA, Mamiya N, Fann AV, Gellman H, Skinner RD, Garcia-Rill EE. Modulation of the sleep state–dependent P50 midlatency auditory-evoked potential by electric stimulation of acupuncture points.ObjectiveTo determine if the P50 midlatency auditory evoked potential, a sleep state–dependent waveform thought to be generated by the reticular activating system, is modulated after surface stimulation of acupuncture points (ie, electroacupuncture).DesignP50 potential recordings were carried out before, during, and after electroacupuncture.SettingA clinical research center.ParticipantsEighty healthy subjects ages 25 to 55 were recorded in 7 investigations.InterventionsStimulation of 3 specific acupuncture points (Pericardium 6, Heart 3, Liver 3) was compared with no stimulation or with stimulation of control points (Gall Bladder 34, Large Intestine 11, Small Intestine 3). We compared different frequencies of stimulation (5, 60, 100Hz), unilateral versus bilateral stimulation, and the effects of repeated episodes of stimulation.Main Outcome MeasuresP50 auditory evoked potential latency, amplitude (measure of level of arousal), and habituation (measure of sensory gait) at interstimulus interval of 250ms.ResultsElectroacupuncture at specific points decreased P50 potential amplitude versus electroacupuncture at control points (P=.006) or versus no stimulation (P<.001). The optimal effective frequency was 5Hz (P<.05 at 5Hz, P>.05 at 60 and 100Hz), and unilateral electroacupuncture was not as effective as bilateral electroacupuncture (P=.007). Repeated episodes of bilateral electroacupuncture showed additive effects (P<.05). There were no differences in responsiveness across sexes (P=.79), and electroacupuncture did not affect P50 potential habituation (P>.05).ConclusionsElectroacupuncture may be effectively used to decrease arousal levels, perhaps as adjunct therapy for disorders of hypervigilance.