Methods: By recording the action potential of sciatic trunk and contract curve of sural muscle of hoptoad, and checking the time of fatigue in nerve center, neuro-muscular junction and muscle.

• 方法:记录蟾蜍坐骨神经干动作电位和腓肠肌收缩曲线,测定低位运动中枢、神经-肌接头和骨骼肌出现疲劳的时间并加以比较。