Changes in electroconvulsive thresholds and patterns in rats after x-ray and high-energy proton irradiation.

Abstract

Electroshock seizure threshold and pattern were altered after X-irradiation or proton irradiation of rats. Radiation acted both directly (after head irradiation) and indirectly (through peripheral damage after body-alone irradiation) to lower the electroshock seizure threshold during the early postirradiation period. It acted only in a direct manner thereafter. Increased susceptibility to seizures, as demonstrated by a reduction of threshold, occurred after doses of 450 or 950 R directed to the head, body only, or whole body, or after 500 to 10,000 rads of protons directed to the head. Seizure intensity, as indicated by the maximal seizure pattern, increased after 500 rads of protons, but decreased after 5000 or 10,000 rads of irradiation to the head. Radiation appears to be excitatory at the lower doses used in the present experiment in regard to both seizure initiation and maintenance, but to be anticonvulsant at higher doses in regard to seizure maintenance.