The effects of low-dose, high-LET radiation exposure on three models of behavior in C57BL/6 mice.

To investigate the behavioral consequences of exposure to whole-body irradiation such as might occur for astronauts during space flight, female C57BL/6 mice were exposed to 0, 0.1, 0.5 or 2 Gy accelerated iron ions (56Fe, Z = 26, beta = 0.9, LET = 148.2 keV/microm) of 1 GeV per nucleon using the Alternating Gradient Synchrotron at the Brookhaven National Laboratory. Animal testing began 2 weeks after exposure and continued for 8 weeks. Under these conditions, there were few significant effects of radiation on open-field, rotorod or acoustic startle activities at any of the times examined. The lack of radiation effects in these behavioral models appears to offer reassurance to NASA mission designers. These results suggest that there may be negligible effects of HZE radiation on many behaviors during a 2-8-week period immediately after radiation.