Ill 



case of a poor energy supply and the ensuing low membrane po- 

 tential. If the critical potential is 55 MV and the resting potential 

 100 MV then the end plate has to overcome a barrier of 45 MV. 

 Jerenik and Gerard have shown that the lower this barrier, the 

 poorer the reenergization, the easier the end plate "fires." So we 

 are led to the paradoxical situation that an impaired energy supply 

 causes increased activity and an increased energy supply may cause 

 inactivity making barriers too high to be overcome. 



