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 e arly environmental factors on the voluntary alcohol intake in Wistar rats. Genetic correlates were examined by comparing animals pharmacogenetically s elected for high susceptibility to apomorphine (APO-SUS) with animals selec ted for low susceptibility (APO-UNSUS). Early environmental factors were in vestigated through postnatal manipulations (cross-fostering in APO-SUS and maternal deprivation in APO-UNSUS). Voluntary alcohol intake was measured u sing a two-bottle, free-choice protocol, in which animals could choose eith er 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 postna tal manipulations was detected: neither cross-fostering nor maternal depriv ation influenced the voluntary alcohol intake. As for the influence of gend er on ethanol self-administration, APO-SUS females consume more alcohol tha n APO-SUS males, while no sex differences were observed in APO-UNSUS animal s. (C) 2001 Elsevier Science Inc. All rights reserved.