The induction of oral ethanol self-administration by contingent ethanol delivery.

The necessity of delivering a highly reinforcing stimulus (20% sucrose) contingent upon ethanol consumption in order to induce ethanol self-administration in free-feeding rats was investigated. Rats water deprived for 12-16 h were placed in an environment in which ethanol drinking resulted in the presentation of ethanol. This procedure was successful in inducing and maintaining ethanol self-administration over concentrations of 5-20% (v/v). Compared to a group of rats initially reinforced for drinking ethanol with sucrose presentation, contingent ethanol delivery resulted in greater ethanol self-administration behavior. When 20% ethanol was available the group trained with ethanol had average intake of 0.91 g/kg, whereas the group trained with sucrose had a mean intake of 0.69 g/kg in a 30-min session. The results suggest that ethanol's reinforcing properties are sufficient to establish ethanol self-administration within the context of the inducing environment.