528 



DOROTHEA STARBUCK MILLER 



40r 



DBA/t CONTROLS 6/59 THROUGH 5/60 



-• DBA/2* GLUTAMATE 6/59 THROUGH 2/60 

 • DBA/i*GLUTAKIATE ROOM R (954 



I 5 6-10 11-15 (6-20 2/-25 26-30 31-35 36-40 41-45 46-50 5/-55 56-60 61-65 



LATENCY IN SECONDS 



Fig. 4. Latency of fatal audiogenic seizures in DBA/2 mice, control and injected 

 with 20 mg glutamate during elevated background radiation level. For comparison, 

 curve (from Fig. 3) obtained in Room R during chronic exposure to low level gamma 

 radiation has been repeated. 



that the recent group reared in Room G received as much radiation from 

 fallout as the mice in Room R received from the Co*^" source. 



Discussion 



In these studies we have observed a significant increase in susceptibility 

 to audiogenic seizures following surprisingly low doses of ionizing radiation. 



