[Effect of electroacupuncture of different acupoints on electroretinogram and cerebral visual evoked potentials in healthy subjects]

OBJECTIVE: To observe the effect of electroacupuncture (EA) of different acupoints on electroretinogram (ERG) and cerebral visual evoked potentials (VEP) in healthy subjects so as to evaluate the relative specificity of the function of acupoints. METHODS: A total of 33 healthy adult volunteers were observed in the present study. The subject was asked to lie on a testing bed for a while, two disk electrodes were respectively fixed to the suborbital region and the occiput (the crossing point, 5 cm apart from the right median line of the head and 5 cm above the ear), and the reference electrode was fixed to the medial side of the earlobe for recording ERG and cerebral VEP separately. The testing room was asked to keep faint light during the whole recording process. A flash stimulation (frequency 1 Hz) was applied to the subject\'s eye (with a distance of about 50 cm between the light source and the tested eye, and the other eye was covered by an eyepatch). EA (0.5 Hz, 0.2 ms and 3-4 V) was applied to Guangming (GB 37), Neiguan (PC 6) and Zusanli (ST 36) for 30 min respectively in different testing days (with the interval being 3 days at least). ERG and cerebral VEP were recorded by using Polygraphy (RM-6200). RESULTS: Following EA of Guangming (GB 37), Neiguan (PC 6) and Zusanli (ST 36),the changing values (increase and decrease) of the amplitude of b waves of ERG and P100 waves of cerebral VEP were (19.68 +/- 12.61)% and (12.84 +/- 14.08)%, (6.09 +/- 14.06)% and (5.61 +/- 8.01)%, (2.39 +/- 3.52)% and (5.43 +/- 8.22)%, respectively, while those of b waves of ERG and P100 waves of cerebral VEP of GB 37 were significantly bigger than those of PC 6 and ST 36 (P < 0.01). CONCLUSION: EA of Guangming (GB 37)can significantly change the amplitude of both ERG and cerebral VEP in volunteer subjects, which is markedly bigger than those of EA of Zusanli (ST 36) and Neiguan (PC 6), suggesting a relative specificity of the effect of EA of different acupoints.