Dopaminergic neurons mediate male Drosophila courtship motivational state

Abstract

Motivational states are important determinants of behavior. In Drosophila melanogaster, courtship behavior is robust and crucial for species continuation. However, the motivation of courtship behavior remains unexplored. We first find the phenomenon that courtship behavior is modulated by motivational state. A male fly courts another male fly when it first courts a decapitated female fly however, male- male courtship behavior rarely occurs under normal conditions. Male flies that have satisfied the need for sexual behavior show a decreased male-female sex drive. Therefore, in this phenomenon, the male flys courtship motivational state is induced by its exposure to female flies. Blocking dopaminergic neurons by expressing TNTe decreases motivational state-induced male-male courtship behavior without affecting male-female courtship behavior. Vision cues are another key component in sexually driven male-female courtship behavior. Here, we identify a base theory that the inner motivational state could eventually decide fly behavior.