Reduced ethanol self-administration in rats produced by the introduction of a high value non-drug alternative reinforcer

Abstract

Previous studies have shown that providing rats with a non-drug alternative in a choice situation can reduce ethanol taking in rats. There is also evidence that brief experience with non-drug reinforcers can reduce the reinforcing effects of drugs like cocaine, even when those non-drug alternatives are not pitted against the drug in a choice procedure. The goal of the present experiment was to determine whether experience with sucrose – a high value non-drug reinforcer in rats – in a non-choice situation would reduce ethanol's reinforcing effects, as measured within a behavioral economic framework. In a first phase, separate groups of rats worked on fixed-ratio schedules for ethanol, sucrose, or ethanol plus sucrose (during separate components within a session). In a second phase, all rats worked for ethanol and sucrose during alternating components. The introduction of sucrose components in the second phase to the group that previously only had experience with ethanol caused a significant decrease in ethanol self-administration. There was also a significant interaction whereby the effect of phase on the elasticity of demand for ethanol differed between the group that only had ethanol and the group that had ethanol plus sucrose in the first phase. These results indicate that a high value non-drug alternative reinforcer can reduce ethanol's reinforcing effects even when that alternative is not available at the time when ethanol is available. These findings suggest that treatments aiming to increase exposure to non-alcohol sources of reinforcement might be beneficial in reducing alcohol drinking.