Undergraduate Research and Creative Activities Journal

Alcohol use disorder alters cognition, risk evaluation, and behavior across species. Drosophila melanogaster larvae are innately attracted to ethanol in nature, where moderate concentrations enhance fitness but higher levels increase mortality. Their conserved alcohol tolerance and withdrawal phenotypes make them a tractable model for studying how dependence alters survival-relevant decision-making. We investigated how alcohol dependence and withdrawal impact larval risk-taking using the dig-and-dive assay, where larvae explore agarose chambers under hypoxic conditions guided by odor gradients. We hypothesized that acute ethanol exposure would suppress exploration, while ethanol-dependent larvae in withdrawal would show hyperexcitability characterized by increased surfacing, decreased digging, and similar levels of diving. Canton-S larvae were chronically exposed to 5% ethanol food for six days to establish dependence, then either tested immediately (inebriated group) or after 1-2 days on ethanol-free food (withdrawal group). Control larvae were reared on standard food. Behaviors were quantified using automated tracking. Preliminary results suggest ethanol withdrawal alters exploration strategies, increasing surfacing frequency and reducing digging while leaving diving unchanged. These patterns are consistent with dopaminergic disruption, blunted threat perception, and impaired valuation of environmental risks. Findings highlight the value of larval Drosophila as a model for linking ecological decision-making with neural mechanisms of addiction.