RADIATION AND AUDIOGENIC SEIZURES IN MICE 



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LATENCY IN SECONDS 



Fig. 3. Latency of fatal audiogenic seizures in DBA/2 mice, control and injected 

 with glutamate, 20 mg per 10 gm body weight. In Room R, the mice were exposed 

 chronically to gamma radiation at 5 to 10 times background. Room G was at low 

 background level. 



In addition to the striking increase in seizure frequency, the latency of 

 fatal seizures also reflected the higher susceptibility of the mice in response 

 to the higher background level. Figure 1 compares the latency of fatal seiz- 

 ures in Fi males, controls and those irradiated at Argonne Hospital, during 

 the two 6-month periods before and after May, 1957. In each period, the 

 latency was shorter following irradiation at 1.5-2 r, with an earlier peak 

 and few delayed seizures. However, during the high background period 

 (May to October, 1957), the latency of seizures in the controls was 

 shorter than in the earlier irradiated group. Irradiation at this time pushed 

 the curve even farther to the left, in the direction of earlier seizures. Figure 

 2 presents similar comparisons in Fi females. In all groups, the latency was 

 shorter in males than in females. 



Following the sudden rise in radioactive fallout in April, 1957, the back- 



