Prenatal ethanol exposure induces a conditioned preference for ethanol in the infant rat.

ARIAS, C; CHOTRO, M.G

Dijon

Congreso; XVIth Congress of the European Chemoreception Research Organisation (ECRO); 2004

European Chemoreception Research Organisation (ECRO).

Previous studies have demonstrated that rats exposed to a moderate dose of ethanol during the last days of gestation (17-20) show higher ethanol consumption during infancy. It was hypothesized that this increased ethanol intake could reflect a conditioned preference established prenatally after the association between the chemosensory aspects of ethanol and its reinforcing properties mediated by the opioid system. Recent data from this laboratory indicate that when ethanol is administered to the pregnant dam together with Naloxone, the effect of enhanced ethanol intake is drastically reduced. However, taking into account that changes in the consumption patterns of a substance does not necessarily reflect changes in its palatability, the above mentioned hypothesis was further investigated evaluating not only ethanol intake but also their behavioral reaction to the taste of ethanol using a taste reactivity test adapted for infant rats. Wistar pregnant rats were intragastrically administered during gestational days 17-20 either water or ethanol (2 g/kg) followed immediately by a subcutaneous injection of either saline or Naloxone (10 mg/kg). On postnatal day 14 pups were tested in their behavioral reaction to the taste of either ethanol, a solution of sucrose+quinine (which resembles the taste of ethanol in rat) or water. The following day, intake of those same substances was evaluated. Pups prenatally treated with ethanol and saline consumed more ethanol and displayed more mouthing in reaction to ethanol taste than those pups exposed to ethanol and Naloxone or than pups never exposed to ethanol before. Ethanol prenatal treatment also increased intake of the sucrose+quinine solution. These results together with previous data from this laboratory support the hypothesis of a conditioned preference to ethanol established in utero mediated by the opioid system.