Spatial Avoidance in the Rat as a Result of Exposure to Ionizing Radiation

Rats were exposed to radiation while confined to one of two distinctive compartments of an enclosed alley. On the next day these animals were confined to the opposite compartment for a similar period in the absence of radiation. Following a series of four such cycles the partition between the two compartments was removed and the animals were given a free choice of residence in the alley for a test period. With but one exception, all the irradiated animals demonstrated a decreased preference for the compartment in which they had been exposed when compared to their preirradiation test scores. It was concluded that both γ and X rays can serve as unconditioned stimuli in the establishment of spatial avoidance behaviour.