Role of mu, delta and kappa receptors upon ethanol intake and ethanol-mediated locomotors stimulation in preweanling rats.

MILLER, S.; ARIAS, C.; SPEAR, N.E.

Congreso; International Society for Developmental Psychobiology; 2009

Clinical and preclinical studies have shown that prenatal ethanol is a good predictor of ethanol use and abuse later in life. In addition, similar to adults, infant rats with higher locomotor activity to a novel environment (?high responders?; HR) are more sensitive to stimulating effects of ethanol than low responders (LR). Infant HR also are more resistant to the aversive effects of ethanol than LR. In Experiment 1 we tested the hypothesis that prenatal ethanol exposure and baseline activity levels interact to determine ethanol consumption during infancy. In Experiment 1 Sprague-Dawley pregnant dams were administered water or 2 g/kg ethanol intragastrically from gestation day 17 (GD17) through GD20. On postnatal day 13 (PD13) pups were given a water intake test, followed on P14 and P15 by ethanol intake tests. Baseline activity was measured before each intake test. Infant male rats with prenatal exposure to ethanol consumed more ethanol than males prenatally exposed to water. Furthermore, infant HR rats consumed more ethanol than LR rats. No differences in consumption of water was evident as a function of prenatal ethanol or baseline activity conditions. HR and LR rats were equally distributed across prenatal treatments. Experiment 2 was designed to compare the effect of prenatal ethanol in two different rat strains, Wistar and Sprague-Dawley. Results indicated that prenatal ethanol signifcicantly increased ethanol intake in both strains. The present data confirm that prenatal ethanol enhances ethanol intake in preweanling rats, and also indicate that baseline activity can be a good predictor of ethanol response during early ontogeny. The possibility that early detection of behavioral phenotypes can predict particular responses to drugs of abuse would be beneficial for early therapeutic intervention.