Alcohol intoxication induces preferences or aversions as a function of age in preweanling rats.

ARIAS, C; CHOTRO, M.G

Washington

Congreso; 38th Annual Meeting of the International Society for Developmental Psychobiology; 2005

International society for Developmental Psychobiology (ISDP)

The few studies that have analyzed the unconditioned effects of alcohol before postnatal day 10 in the rat, either failed to find an effect or reported a conditioned preference. This could be explained considering the hypothesis of a sensitive period that ends on postnatal day 9 (PD 9), in which pups easily learn preferences for odors, even when paired with aversive unconditioned stimuli (Sullivan, Landers, Yeaman & Wilson, 2000). During this sensitive period the opioid system plays a critical role in the acquisition of learned preferences. Considering that the reinforcing effects of alcohol are mediated by this neurochemical system, it seems possible that during this period the infant rat may learn preferences to alcohol after been intoxicated with relatively high alcohol doses. This was investigated in a series of experiments, in which rat pups were intoxicated with alcohol (3 g/kg) before or after PD 9. Taste reactivity to alcohol and alcohol intake were later tested. The results indicated that before PD 9 alcohol intoxication induced a preference for alcohol, while few days later the same alcohol dose induced a conditioned aversion. In another experiment it was observed that the administration of naloxone before alcohol intoxication prevented the conditioned preference before PD 9, but did not affect the aversion acquired after the sensitive period. These results suggest that during the first postnatal days of the rat there are developmental changes in the perception of the unconditioned effects of alcohol.