In mammals, investigations using diverse methods have converged on the conclusion that natural rewards and addictive drugs alike influence behavior as a result of their ability to increase synaptic dopamine in the nucleus accumbens1,14. Although dopamine plays a role in the acute locomotor effects of cocaine and ethanol in flies15,16, it is unknown whether it also plays a role in ethanol reward. We therefore blocked dopaminergic neurotransmission with spatial and temporal resolution in behaving flies to investigate a potential role for dopamine in the aversive and rewarding effects of ethanol. To do this, we expressed the dominant-negative and temperature-sensitive variant of dynamin, Shibire temperature-sensitive (Shits), in dopaminergic neurons using the GAL4-UAS binary expression system17. At temperatures at or above 29°C, Shits rapidly impairs synaptic transmission in targeted neurons by inhibiting neurotransmitter vesicle recycling17. We silenced dopaminergic neurons using two different GAL4 drivers: one expressed under the control of the tyrosine hydroxylase promotor (TH-GAL4, expressed in most dopaminergic neurons18) and one under the control of dopamine decarboxylase (Ddc-GAL4, expressed in most dopaminergic and serotonergic neurons19). Perturbing neurotransmission in Ddc– or TH–
