Audiogenic seizure in genetically susceptible mice: Relation of hypothermia to onset and susceptibility

Abstract

The protective effect of reduction of body temperature against audiogenic seizure was investigated in a strain of mice genetically predisposed to audiogenic seizure. Mice were dipped in a cold detergent solution and exposed to cold (2 ± 0.5 C air temperature) for 2, 3, 4, 5 or 6 min and promptly subjected to a standard sound stimulus. Ninety-two percent of the animals with colonic temperatures reduced to within the range of 34.5–29.0 C showed elevated latencies to seizure; two animals (colonic temperature 29.0 and 29.4 C) failed to convulse. Of the animals with colonic temperatures reduced to 27–29 C, 69 per cent were completely protected against audiogenic seizure. Complete protection occurred in all animals with colonic temperatures below 27.0 C. Those that failed to convulse while hypothermic were retested under euthermic conditions 90 min after the exposure to cold. Prolonged latency to seizure was observed in 80 per cent of the animals that convulsed during this retest. When tested again under euthermic conditions 24 hours after the exposure to cold 89 per cent of the mice exhibited convulsions, and the latencies to seizure did not significantly differ from those of the control animals tested at this time.