114 



HAROLD KOENIG 



Rt. frontal lobe 



Transverse frontal 



Vl 



Fig. 7. EEG 16 days after injection of 6 mg FO into right frontal lobe. Note 

 numerous spikes. Pentobarbital anesthesia. 



Mit¥ 



Rl. fronUl loll,. 



V/'-'v^vv-i 



Ll. frontal lobe 



/^"^'L^l'l' 



Fig. 8. EEG 15 days after injection of 6 mg FO into right frontal lobe. Note 

 paroxysm of high voltage activity. Pentobarbital anesthesia. 



beconie.s dilated, and the nictitating membrane retracts. Focal electroen- 

 cephalographic defects appear 2 to 4 days after injection, with slow waves, 

 sharp waves, and spikes (Figs. 9 and 10). Some of these abnormal rhythms 

 are propagated to the opposite temporal lobe. Spontaneous focal and general- 

 ized electrical seizures occur, even though animals are under pentobarbital 

 anesthesia. Cytopathologic changes occur in cortical neurons which are simi- 

 lar in character to those observed when FO is administered elsewhere in the 

 central nervous system. However, the changes are mild and often unrecog- 

 nizable when neuronal dysfunction is present. 



