PERSISTENCE OF ETHANOL-INDUCED SENSITIZATION DURING THE PREWEANLING PERIOD OF THE RAT.

CASTELLÓ, S.; DALOISIO, G; MOLINA, J.C.; ARIAS, C.

San Sebastián

Congreso; INTERNATIONAL SOCIETY FOR DEVELOPMENTAL PSYCHOBIOLOGY 48TH ANNUAL MEETING; 2015

Drugs of abuse as amphetamine or cocaine induce sensitization to the locomotor stimulating effect in adult and in preweanling rats. However, during infancy this learning effect is observed only after a short interval of time, between training and testing. During infancy, particularly during de 2nd postnatal week of life, rats are highly sensitive to ethanol. In a previous study we have shown short-term ethanol-induced sensitization when subjects were trained during the 2nd postnatal week. This effect was context-dependent, in that it was only observed when pups were trained and tested in different contexts. The present series of experiments was designed to explore the persistence of the sensitization effect across the preweanling period. Pups were trained with ethanol during the second or the third postnatal week of life, and were tested 2 or 7 days later. Our results showed that, contrarily to what has been observed with other drugs during infancy, sensitization to ethanol persisted at least 7 days in rats trained during the 2nd postnatal week of life. In older pups, the same procedure induced tolerance instead sensitization. This pattern of results suggests that infancy is a valuable period for the study of the neurobiological determinants underlying ethanol-induced sensitization and the relationship of this effect with ethanol intake.