Effects of bremsstrahlung and electron radiation on rat motor performance

Relatively high, rapidly delivered doses of ionizing radiation have been reported to produce an immediate decrement in performance (PD) in a number of animal species. This study investigated the effects of bremsstrahlung and electron radiation on the performance of rats unilaterally exposed by a linear accelerator (LINAC facility) at a midline tissue dose rate of 2000 rad/min. Relative radiation effects were determined by establishing median effective doses (ED50) for rats trained on the accelerod, which is a shock-avoidance test of motor performance. The ED50 was 8121 rad for the bremsstrahlung field and 6110 rad for the electron field, for a significantly different relative effectiveness of the electron field in producing PD of 1.35. The data imply that different radiation fields are not equally effective in producing PD