Prenatal exposure to morphine affects both neurological development and behavior of infants. Both rat pups and human infants born after prenatal exposure to morphine exhibit withdrawal and abnormal behavior, indicating that morphine affects development of the central nervous system (CNS). Mechanisms of mother-infant attachment in both species involve associative learning mediated by the CNS. Rat pups exhibit a sensitive period for learning these associations, dependent upon norepinephrine. Also, endogenous opioids are involved in early associative learning. The extent of interaction of both endogenous opioids and norepinephrine is not known. Are these two learning systems independent of one another, or is input necessary from both systems for early associative learning? The specific aims of this proposal are to determine the role of opioids in early olfactory associative learning and to determine the extent of the interaction between these two learning systems. Overall, a better understanding of the role of opioids in early learning would aid in the understanding of the consequences of prenatal exposure to morphine, which affects both learning systems, on the development of the CNS and mother-infant attachment.
