Time course of radiation-induced taste aversion conditioning

Taste aversion conditioning was used to define the onset and duration of the period after exposure to 100 R gamma radiation which was most aversive to the animal. Rats were irradiated and then allowed to drink a saccharin solution. A significant decrement appeared in their cumulative intake, compared to sham animals at 90 min postexposure. When time delays between 0-90 min were imposed between offset of the radiation beam (US) and onset of saccharin exposure (CS), the time at which a significant decrement in saccharin drinking occurred remained constant at 90 min. With US-CS delays of 2, 4, and 6 hr a weaker aversion was found in terms of the time span before a significant decrement in the irradiated groups' saccharin drinking rate appeared. Groups which were irradiated then allowed access to tap water for 24 hr, either immediately or 1.5 hr after radiation offset, showed no decrement in their water drinking rate with respect to a sham control. The procedures used in this experiment provide a method for measuring the latency of onset of subtle physiological effects.