A hallmark of addiction is continued drug use despite negative consequences. To examine if our assay could be used to test addiction-like behavior, we asked if flies would overcome an aversive stimulus to gain access to the odor previously associated with ethanol. Indeed, conditioned flies showed reduced aversion to both 100 V and 120 V electric shocks; an effect not observed in flies exposed to either odor or ethanol alone (Fig. 1d, Supplementary Fig. 3a).
