DEVELOPMENT OF MATERNAL RESPONSIVENESS IN RAT

Maternal responsiveness in the rat develops gradually during pregnancy and parturition, and in the postpartum period of maternal care. Virgins can be shown to have a basic level of maternal responsiveness, which is raised during pregnancy and again at parturition. After parturition the young maintain the mother's maternal responsiveness, but there are indications that as they grow older they cause a decline in her responsiveness. Maternal responsiveness is shown to be based upon substance(s) carried in the blood of the postparturient mother. Transferring blood plasma from a new mother to a virgin causes the latter to become maternal towards young within 48 hours, where normally it requires two to three times this period of exposure to young. 1969 American Orthopsychiatric Association