METABOLISM IN CHANGED CEREBRAL ACTIVITY 



57 



terms of the expenditure of energy during convulsive activity 

 exceeding the energy production by oxidative mechanisms (Stone 

 et al, 1945). However, ahhough the arterial oxygen tension 

 remained above levels known to induce hypoxic changes (Table 11), 



Table 11. — Effect of Metrazole-induced Convulsive 

 UPON Levels of Cerebral Phosphates 



Activity 



Data from Stone et al. (1945). 



such measurements record only that the oxygen supply is poten- 

 tially adequate. Thus the changes in phosphate levels could have 

 been secondary to a local hypoxia accompanying the increased 

 metabolism (see Klein and Olsen, 1947). Localized changes in the 

 oxygen tension of the cortex were measured by Davis et al. (1944), 

 Davies and Remond (1947), and Gurdjian et al. (1947). In dogs 

 receiving metrazole, although convulsive activity was accompanied 

 by a drop in the cortical oxygen tension, at no time did this fall to 



5— PMB 



