Neuroanatomical basis of maternal memory in postpartum rats: Selective role for the nucleus accumbens

The experience of interacting with pups causes long-term changes in mothers ' brains that mediate long-term changes in maternal behavior. As little as 1 hr of pup experience postpartum results in enhanced maternal responses to pups 10 days later. This experiment investigated the effects of lesions in multiple neural sires that have been implicated either in the actual expre ssion of maternal behavior or in learning and memory within other behaviora l contexts on the initiation and the long-term experience-based retention o f maternal behavior. Electrolytic lesions were performed either before or a fter a 1-hr or 24-hr maternal experience. Rats sustaining lesions of the nu cleus accumbens (NACC), whether administered before parturition and experie nce or immediately after a brief experience, failed to show a maternal expe rience effect. NACC lesions sustained 24 hr after a maternal experience did not disrupt long-term retention of the maternal behavior.