Neurobiology of mother-infant interactions: experience and central nervoussystem plasticity across development and generations

The optimal coordination between the new mammalian mother and her young inv olves a sequence of behaviors on the part of each that ensures that the you ng will be adequately cared for and show healthy physical, emotional, and s ocial development. This coordination is accomplished by each member of the relationship having the appropriate sensitivities and responses to cues tha t characterize the other. Among many mammalian species, new mothers are att racted to their infants' odors and some recognize them based on their odors ; they also respond to their infants' vocalizations, thermal properties, an d touch qualities. Together these cues ensure that the mother will nurse an d protect the offspring and provide them with the appropriate physical and stimulus environment in which to develop. The young. in rum, orient to the mother and show a suckling pattern that reflects a sensitivity to the mothe rs odor, touch, and temperature characteristics. This article explores the sensory, endocrine, and neural mechanisms that underlie this early mother-y oung relationship, from the perspective of, first, the mother and, then, th e young, noting the parallels between them. It emphasizes the importance of learning and plasticity in the formation and maintenance of the mother-you ng relationship and mediation of these experience effects by the brain and its neurochemistry. Finally, it discusses ways in which the infants' early experiences with their mothers (or the absence of these experiences) may co me to influence how they respond to their own infants when they grow up, pr oviding a psychobiological mechanism for the inter-generational transmissio n of parenting styles and responsiveness. (C) 1999 Elsevier Science Ltd. Al l rights reserved.