HIPPOCAMPAL LESIONS IN RATS WEAKEN RETROGRADE AMNESIC EFFECT OF ECS

19 rats with hippocampal lesions and 14 control rats were trained in an approach response to water. 7 Ss of each group received foot shock only, 7 received foot shock folowed in 4 sec. by ECS, and 5 Ss with hippocampal lesions received ECS alone. Ss with hippocampal lesions showed longer latency approach responses than did control Ss on a test trial 24 hr. after foot shock plus ECS. Both Ss with hippocampal lesions and control Ss were inhibited in approach to water after foot shock alone. The results support the hypothesis that the hippocampus plays an important role in retrograde amnesia. (PsycINFO Database Record (c) 2006 APA, all rights reserved). © 1968 American Psychological Association.