Emotional memory and hippocampus

We compared emotional responses (behavioral and histochemical) to contextual fear conditioning between young and aged rats. Freezing behavior right after footshock did not differ between the two groups. However, in an hour the freezing behavior as well as phospho-cAMP-responsive element-binding protein (pCREB) in CA1 area of the hippocampus significantly increased in the young rats. pCREB is considered to be involved in learning and memory. The number of pCREB positive cells did not change in other areas of the hippocampus or other brain areas in either the young or aged groups. The number of positive cells to cAMP-responsive element-binding protein did not change in either the young or aged groups. These results indicate that a transcription factor pCREB and its products in CA1 area may be responsible for the emotional memory consolidation by the contextual fear conditioning.