Dopaminergic neurons mediate male Drosophila courtship motivational state

Motivational states are important determinants of behavior. In Drosophila melanogaster, courtship behavior is robust and crucial for race continuation. However, motivation of courtship behavior remains untouched. We first find the phenomena that courtship behavior is modulated by motivational state. Male fly courts to male fly when it firstly courts to decapitated female fly, however male-male courtship behavior rarely happens under normal condition. Male fly with satisfied sexual behavior shows decreased male-female sex drive. So in this phenomena male fly9s courtship motivational state is induced by its exposure to female fly. Blocking dopaminergic neurons by expressing TNTe decreases motivational state induced male-male courtship behavior without affecting male-female courtship behavior. Vision cue is another key in sexual driven male-female courtship behavior. Such we identify a base theory that inner motivational state could decide fly9s behavior eventually.