Maternally separated rats show deficits in maternal care in adulthood

Although there is considerable research on the phenomenology, neuroendocrin ology, neuroanatomy, and sensory control of maternal behavior; little is kn own about the influences of early postnatal and postweaning experiences on the development of maternal behavior The pur-pose of this study was to asse ss how early life separation from the mother I at affects development of th e off-spring's juvenile and adult maternal behavior: From postnatal Days I to 17, 3 female rats within each litter were separated (SEP) from the mothe r and the rest of the litter for 5 hr daily while 3 of their sisters were n ot maternally separated (NSEP). On postnatal Day 21, all subjects were wean ed and randomly assigned to one of three juvenile conditions. One female fr om both SEP and NSEP groups was either isolated (I), given a social conspec ific (S), or given 1- to 4-day-old pups (P) for 5 consecutive days. Materna l behavior of SEP and NSEP animals was assessed and recorded on each of the 5 days. Once all animals reached adulthood, they were mated gave birth, an d were assessed for their maternal behavior We found that the effects of ma ternal separation on juvenile maternal-like behaviors were minimal. On the other hand, maternal separation reduced adult maternal licking and crouchin g over pups. In addition, there was a significant interaction between postn atal and juvenile experience on maternal crouching in maternal animals. The se results are discussed in terms of the variety of possible behavioral, en docrine, and neurochemical mechanisms that mediate the effects of early lif e experiences on adult maternal behavior (C) 2001 John Wiley & Sons, Inc.