Estudios previos muestran que la exposición a dosis bajas o moderadas de alcohol (1 o 2 g/kg) durante los días gestacionales 17-20 incrementa el consumo de alcohol en crías de rata.. Teniendo en cuenta que un mayor consumo no implica necesariamente una pr

ARIAS, C.; CHOTRO, M. G.

Congreso; Sociedad Espanhola de Psicobiologia; 2004

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. In the first experiment, Wistar pregnant rats were intragastrically administered during gestational days 17-20 either water or ethanol (1 or 2 g/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. In the second experiment, pregnant rats were intragastrically administered with water or ethanol (2 g/kg) followed immediately by a subcutaneous injection of either saline or Naloxone (10 mg/kg). Intake and behavioral reactions to the taste of ethanol and sucrose+quinine were also measured in this experiment. In both experiments, pups prenatally treated with ethanol consumed more ethanol, and displayed more mouthing in reaction to ethanol and sucrose+quinine tastes than those pups never exposed to ethanol before. In the second experiment, pups prenatally exposed to ethanol and Naloxone did not show this higher intake of ethanol, and displayed less mouthing when tested with ethanol or sucrose+quinine than those exposed prenatally to ethanol and saline. 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