A novel mouse home cage lickometer system reveals sex- and housing-based influences on alcohol drinking.

Loneliness has been associated with increased alcohol use, and traditional rodent drinking models involve single housing, presenting challenges for studying social enrichment. Here we developed LIQ PARTI (Lick Instance Quantifier with Poly-Animal RFID Tracking Integration), an open-source group-housed lickometer system to investigate how social housing, isolation, and sex influence alcohol consumption patterns in C57Bl/6J mice. LIQ PARTI accurately identifies mouse drinking events and uncovered significant housing- and fluid-dependent diferences in ethanol consumption and bout microstructure between male and female mice. Social isolation-induced changes to ethanol drinking behavior and microstructure were highly plastic, as resocialization generally reversed these changes. These findings expand on the complex interplay between sex, social isolation, and alcohol use.