Genetic, sex, and early environmental effects on the voluntary alcohol intake in Wistar rats.

The aim of this study was to investigate the effects of genetic, sex, and early environmental factors on the voluntary alcohol intake in Wistar rats. Genetic correlates were examined by comparing animals pharmacogenetically selected for high susceptibility to apomorphine (APO-SUS) with animals selected for low susceptibility (APO-UNSUS). Early environmental factors were investigated through postnatal manipulations (cross-fostering in APO-SUS and maternal deprivation in APO-UNSUS). Voluntary alcohol intake was measured using a two-bottle, free-choice protocol, in which animals could choose either water or an ascending series of alcohol concentrations every second day. Genetic correlates were only observed in male rats, with APO-UNSUS animals consuming more alcohol than APO-SUS animals. No effect of the early postnatal manipulations was detected: neither cross-fostering nor maternal deprivation influenced the voluntary alcohol intake. As for the influence of gender on ethanol self-administration, APO-SUS females consume more alcohol than APO-SUS males, while no sex differences were observed in APO-UNSUS animals.