Patterns of electrogenic seizures in rats: their relation to stimulus-intensity and to audiogenic seizures.

Abstract

From 7-14 milliamperes (neglecting skull resistance considered low in comparison with circuit resistance) was passed through the head from the secondary of a 60 cycle power transformer at 700 v. through a resistance of from 50,000 to 100,000 [image]. Four types of seizures are described, tonic-clonic, tonic, clonic, and racing, the first being the most severe, the last, least. On the first day the duration of stimulation was 0.95 sec. but on all other days it was 0.75 sec. Eight animals received one shock/day for 7 days, the current being reduced 1 milliampere/day from 14 milliamperes on the 2d day to 9 milliamperes on the 7th. The more severe seizures occurred on the earlier days, and it is suggested that the more intense stimulation gives rise to the more severe seizures. There is some discussion of the relation of these findings to the problem of the nature of audio-genic seizures.