Comparative Effects of Bremsstrahlung, Gamma, and Electron Radiation on Rat Motor Performance

The effects of rapidly delivered supralethal doses of bremsstrahlung, electron, and gamma radiation were investigated on the performance of male Sprague Dawley rats exposed at a midline tissue dose (MTD) rate of 2000 rad/min. The bremsstrahlung and electron radiations were produced in a linear accelerator (LINAC), and the gamma radiation was produced in a 60 CO facility. Relative radiation effects were determined by establishing median effective doses (ED50) for rats trained on the accelerod, a shock-avoidance test of motor performance. ED50's were based on 10-min post-exposure performance. The ED50 was 8121 rad for the bremsstrahlung field, 6110 rad for the electron radiation, and 3896 rad for the gamma photons. No significant difference was found between the bremsstrahlung and gamma radiations even though the physical characteristics used to achieve the two fields were less uniform in the bremsstrahlung exposures. However, the other ED50's translate into significantly different relative effectiveness of 1.35 between the bremsstrahlung and electron fields, and 1.45 between the electron and gamma radiations. The data imply that different radiation fields are not equally effective on behavior. This article is from 'Proceedings of the Symposium: Psychology in the Department of Defense (9th) Held at Colorado Springs, Colorado on 18-20 April 1984', AD-A141 043, p68-72.