Effects of cortical lesions upon audiogenic seizures.

Abstract

Sixty-two rats of varying age, color, and sex, but of known audiogenic seizure history were divided on the basis of tests into groups of high and low susceptibility. Some animals of each group were subjected to ablation of motor areas and some to auditory areas, while some in the low susceptibility group were subjected to "pre-frontal lobectomy," and some in the high susceptibility group served as operate controls, the skull being trephined, but no cortical tissue removed. Mortality was unexpectedly high[long dash] over 40%, and some of this excessive mortality was tentatively ascribed to the audiogenic history of the animals. Twenty-one operated animals survived. The susceptibility of the "prefrontal lobectomy" animals was decreased. That of the auditory group was also depressed. The seizures of the motor area group were decreased in frequency, but the proportion of seizures which were convulsive increased from 64% to 100% and duration of seizures increased.