Recovery of Central Nervous System Functions Impaired by Lethal Head X-Irradiation. ∗

Summary

The effects of X-irradiation on the response to maximal electroshock and on EEG have been studied in head irradiated rats at various intervals following irradiation. A single application of 10,000 r to head of rats was found to induce a progressive increase in protection against maximal electroshock. This apparent anti-convulsant effect reached a maximum by about 48 hours post-irradiation and was then rapidly lost. Most of the animals died by the 7th or 8th day following irradiation. It is of interest that the irradiated animals progressively recover their ability to respond to maximal electroshock after the 48 hour period in spite of their otherwise increasing moribund state. EEG records following irradiation also suggest a similar recovery effect. These findings are interpreted as indicating that there is a progressive recovery of certain central nervous system functions impaired by a lethal dose of X-irradiation.