OBJECTIVE:To investigate the effects of different frequencies of electro-acupuncture at Shuigou (GV 26) on the latent period and wave amplitude of motor evoked potentials (MEPs) in rats with focal cerebral infarction.METHODS:Fifty healthy male Wistar rats were randomly divided into five groups:controls,model,2 Hz Shuigou,50 Hz Shuigou and 100 Hz Shuigou.There were 10 rats in each group.Using a modification of a technique for middle cerebral artery occlusion,focal cerebral ischemic injury was induced in all rats except those in the control group.The rats in the control group received no treatment.After behavioral deficit had been evaluated using the Zausinger 6-point neurological function score,the rats in the Shuigou groups underwent acupuncture and continuous wave stimulation at a frequency of 2 Hz,50 Hz or 100 Hz (intensity 1 mA) for 10 min twice daily for 3 days.The control and model groups underwent no intervention.Zausinger 6-point neurological function score and MEPs were measured 72 h after the start of treatment.RESULTS:The neurological function scores of the three Shuigou groups were significantly higher than those of the model group (P＜0.05).There was no significant difference between sides in the latency and amplitude of MEPs in the model group (P＞0.05).The latency on the affected side in the model group was significantly longer than that in the control group (P＜0.05) and the amplitude on affected side was significantly reduced (P＜0.01).After 3 days of electro-acupuncture,the latency on the affected side in the 2 Hz Shuigou group was significantly shortened (P＜0.05) and the amplitude was significantly increased (P＜0.05) compared with the model group.CONCLUSION:Low frequency electro-acupuncture at Shuigou (GV 26) can promote recovery of motor function after focal cerebral ischemic injury in rats.