A Drosophila model for alcohol reward

The rewarding properties of drugs contribute to the development of abuse and addiction. Here we present a new assay to investigate the motivational properties of ethanol in the genetically tractable model, Drosophila melanogaster. Flies learn to associate cues with ethanol intoxication and, although transiently aversive, the experience leads to a long-lasting attraction for the ethanol-paired cue, implying that intoxication is rewarding. Temporally blocking transmission in dopaminergic neurons revealed that flies require activation of these neurons to express, but not develop, conditioned preference for ethanol-associated cues. Moreover, flies acquire, consolidate, and retrieve these rewarding memories using distinct sets of neurons of the mushroom body. Finally, mutations in scabrous, encoding a fibrinogen-related peptide that regulates Notch signaling, disrupt the formation of memories for ethanol reward. Our results thus establish that Drosophila can be useful in understanding the molecular, genetic and neural mechanisms underling the rewarding properties of ethanol.