Persistence of ethanol-induced sensitization during the preweanling period of the rat

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

Valencia

Congreso; Congress of the European Society for Biomedical Research on Alcoholism (ESBRA) and 3rd Congress of the Latin American Society for Biomedical Research on Alcoholism (LASBRA); 2015

We have recently reported that a high ethanol dose can induce tolerance to the locomotor stimulating effect of the drug in the infant rat. This effect is context-dependent, because it was exclusively observed when infants were trained and tested in the same context. The aim of the present study was two-fold. First, we explored the persistence of the context-dependent tolerance across the preweanling period; and secondly, we assessed whether different reminder treatments reinstate tolerance after a long-time interval. Subjects were trained with ethanol during the 2nd or 3rd postnatal week of life, and 2 or 7 days later they were tested in response to ethanol in terms of locomotor activity (appropriate control groups were included in all the experiments). Our results showed tolerance only after 2 days of training, while 7 days later, instead of tolerance; sensitization induced by ethanol was observed in both age groups. Finally we also found recovery of tolerance 7 days after training. Different contextual cues controlled all of these effects across ages. These results indicate that both, tolerance and sensitization can be induced during infancy by the same ethanol experience, and that the short- and long-term expression of these processes can be modulated by different contextual treatments. The present results, in agreement with previous studies from our laboratory, show that ethanol during infancy can result in long-term effects that modulate reactivity to the drug later in development.