The effects of hippocampal stimulation in a one-trial appetive learning situation

Abstract

The phenomenon of retrograde amnesia has been widely investigated in connection with the study of memory consolidation. Localized electrical stimulation of the brain has been useful in examining the degree of involvement of different areas of the brain in the production of retrograde amnesia. One of the areas that has been implicated as playing an important role in the consolidation process is the hippocampus. However, it is unclear whether the hippocampus plays a general or a specific role in consolidation, since the majority of the studies examining the effects of hippocampal stimulation used the passive-avoidance paradigm. Therefore, the present study examined the generality of the role of this structure in consolidation by using a one-trial appetitive learning task which involves a different motivational system and different responses than the passive-avoidance task. Experiment 1 established the effectiveness of the one-trial appetitive training procedure in producing learning in the subjects receiving it by comparing the performance of two groups of rats on the task. It was found that rats receiving appetitive training showed superior learning as compared to rats receiving no training.