| Abstract: | Rats were given a footshock followed by ECS of either low or high intensity. Controls received neither footshock nor ECS. Twenty-four hours later all subjects acquired a simple position habit in a water maze. Then, independent subgroups were reversal trained at 24-hr intervals up to 144 hr post-treatment. Compared to controls, rats given footshock, and ECS showed memory for training at the initial test followed by amnesia, memory recovery, and finally amnesia at subsequent tests. The alternating pattern of retention appeared to be a function of ECS intensity. In a second experiment, rats were first maze trained then given footshock and ECS 24 hr later. Like the results of the first experiment, ensuing tests indicated an alternating retention function in experimental animals again influenced by ECS intensity. Several possible explanations of these results were discussed, and it was suggested that the altering retention function observed in the experimental animals resulted from a footshock and ECS induced state dependency effect that subsided and recurred spontaneously up to 144 hr post-treatment. |
