Daily citric acid consumption facilitates binge-like ethanol drinking in mice

Preclinical models of alcohol consumption are critical tools for understanding the biological underpinnings of alcohol use disorder. Through these models, researchers have identified behavioral and biological consequences of acute and chronic alcohol exposure across the lifespan. Here, we present a simple and effective novel method for safely increasing palatable fluid motivation that drives voluntary binge-like alcohol consumption. We replaced open-access water with 1% citric acid water. Mice on citric acid remained healthy and showed no overt signs of dehydration. All animals had access to 15% ethanol for 1 hour per day, five days per week. Animals drinking 1% citric acid consumed significantly more ethanol than mice with home cage water access, with citric acid drinkers reaching intoxication within the hour of open access. Ethanol consumption levels in citric acid mice were similar to consumption seen in animals that have undergone four cycles of chronic intermittent ethanol vapor, a classical model of dependence and high voluntary consumption. Male mice on citric acid consumed equivalent alcohol levels to vapor-exposed animals whereas female mice on citric acid consumed higher levels. These results show that daily maintenance on 1% citric acid facilitates binge-like ethanol drinking, likely through increased motivation to consume palatable fluids including ethanol, and can serve as a tool for further investigation of the biological consequences of excessive drinking and related behaviors.