Early exposure to ethanol induces a conditioned preference for the drug?s flavour.

ARIAS, C; CHOTRO, M.G

Granada - Espana

Simposio; XVIIth Congress of the European Chemoreception Research Organisation (ECRO); 2006

European Chemoreception Research Organisation (ECRO)

During the last days of gestation the fetus can perceive and recognize the chemosensory properties of substances present in the amniotic fluid. Frequently, prenatal exposure to different tastes and odors induces a higher acceptance for them. This same effect has been found in several studies in which fetuses were exposed to moderate ethanol doses during the last days of the gestation. Specifically, the administration of 1 or 2 g/kg of ethanol during gestational days (GD) 17-20 induces higher ethanol intake both in infants and in adolescents. Could this effect be explained by the same mechanisms underlying preferences to other chemosensory stimuli acquired during the prenatal period? Studies in the last fifteen years indicate that fetuses can perceive the ethanol?s chemosensory properties, and associate them with the rewarding properties of the drug, the last ones mediated by the activation of the opioid system. Interestingly, fetuses and infant rats during the first postnatal week can learn a conditioned preference for ethanol?s flavor, even after intoxication with doses that induce taste aversion later in ontogeny. This paradoxical effect could be explained if considering an early sensitive period described by Sullivan and collaborators (Sullivan et al., 2000), in which moderately aversive stimuli exert appetitive effects, and also when the opioid system plays a key role in the acquisition of conditioned preferences.