Octopamine release impairs courtship conditioning in Drosophila melanogaster

Octopamine is known to have an appetitive role in odor conditioning paradigms in Drosophila melanogaster. We sought to test whether octopamine could also act as an appetitive stimulus in courtship conditioning, a paradigm in which training with an unreceptive female (such as a decapitated virgin) causes a subsequent decrease in courtship behavior in male Drosophila. To control octopamine release, we used the Tdc2-Gal4 and UAS-dTRPa1 genes in conjunction to depolarize octopaminergic neurons at 27 C in experimental flies. We hypothesized that inducing octopamine release during courtship training would decrease the aversive impact of training and cause less subsequent suppression of courtship behavior. Our findings confirmed this hypothesis: Tdc2-Gal4/UAS-dTRPa1 flies trained at 27 degrees showed significantly more courtship behavior than controls during testing, and in fact showed no significant effect of courtship training. This confirms that octopamine release counteracts the aversive stimulus of failure to copulate, indicating that octopamine may have an appetitive role in courtship.