Neuromodulatory basis of conflict settlement

A function of aggressive behavior is thought to resolve a conflict over limited resource. Aggressive interaction is often settled by the establishment of "winner" and "loser". While the neural changes associated with winner and loser phenotypes have been extensively investigated, the neural mechanism underlying the transition from active fighting to the establishment of hierarchy has not been well characterized. Using common fruit flies, we have characterized a circuit that controls the timing of settlement. Interestingly, this mechanism promotes a fly to become a loser, which is consistent with the theoretical prediction that the duration of a fight is defined by the timing of defeat. The implication of the neural mechanism of conflict settlement on the evolution of sociality will be discussed.