CONSEQUENCES OF ETHANOL AS THE NEWBORN'S FIRST MEAL

本提案是评估一种新的乙醇自我给药技术

This proposal is to assess a new technique for self-administration of ethanol in neonatal rats, when this ethanol constitutes the newborn's first feeding experience. This technique will be examined for its value in testing two issues -- the consequences of early exposure to ethanol for later responsiveness to ethanol, and the basis of ethanol's reinforcing effects. Perinatal exposure to ethanol is known to influence substantially the rat's later responsiveness to ethanol, in accord with recent evidence that amount of prenatal exposure to ethanol is a good predictor of human ethanol abuse during adolescence. Preliminary studies suggest that the proposed self-administration procedure: (1) has advantages over others used for infant rats; (2) might provide an assay for prenatal consequences of ethanol; and (3) could serve as a potential model of human infant ethanol intake during nursing after the mother consumes ethanol or of prenatal ethanol during the third trimester of the human fetus. Preliminary studies have indicated that newborn rats consume substantial amounts of ethanol from a surrogate nipple and subsequent responsiveness to this nipple simulates that observed after intake of milk (but different from that after intake of other fluids such as water or saline). With these procedures ethanol was consumed at relatively high concentrations when delivered in solution with milk. The first specific aim is to establish optimal parameters for self-administration of ethanol by newborns and assess the reinforcing effects of ethanol with these parameters. The second aim is to assess effects of frequency and dose of prenatal ethanol exposure on the newborn's self-administration of ethanol. The third aim is to study consequences of the newborn's exposure to ethanol delivered in either of two ways, -- through a surrogate nipple or intra orally infused -- on later responsiveness to ethanol. The proposed experiments will evaluate the promise of the proposed self-administration procedure in this advantageously simple mammalian model, for use in understanding the reinforcing effects of ethanol and the effects of ethanol exposure on later responsiveness or sensitivity to ethanol.