Comparison of liquid and gelatin alcohol self-administration methods in Sprague-Dawley rats

It is a methodological challenge to induce robust alcohol self-administration in rats without the use of involuntary consumption methods or sweeteners. The present work compares the efficacy of liquid and gelatin media, with and without sucrose fading, in voluntary alcohol-self administration using a rat Drinking in the Dark paradigm. Sprague-Dawley rats were reared under group housed, enriched conditions. A subset of rats was moved to non-enriched single housing conditions prior to the start of experimentation to model the acute stress produced by isolation housing common to self-administration paradigms. Over the course of 21 days of alcohol self-administration, rats in the gelatin groups consumed more than those in the liquid groups, regardless of sucrose fading condition. Sucrose fading produced a transient increase in self-administration in the liquid group but produced no escalation in gelatin groups. Gelatin groups persist in drinking at higher concentrations of quinine than liquid groups. No effects of housing condition were observed. These findings suggest that robust ethanol self-administration behavior can be established in rats by employing a gelatin medium without the need for acquisition aids such as sucrose.