Humans and other animals wittingly or unwittingly run risk–benefit analyses daily. For animals of reproductive age, a prime example of such analysis is assessing the benefit of reproductive success versus the cost of being preyed upon. The scale needs to be sensitive: over-prioritize survival at the risk of a lack of progeny, or undermine danger at the risk of perishing. While previous studies and empirical knowledge have suggested that males become less preoccupied about potential danger upon permissive cues indicating increased probability of successful copulation, the molecular mechanisms orchestrating this behavior have remained ill-understood.

Writing in Nature, Cazalé-Debat et al. remedy this gap in understanding and provide notable mechanistic and functional insight into the neurons, receptors and signaling cascades that regulate the trade-off between survival and propagation in Drosophila. Using sex–danger conflict assays, the authors demonstrate that though male flies abort courtship upon danger cues at early stages, they increasingly disregard visual threats as courtship progresses and copulation becomes more likely. The initial abortive response seems to be regulated by visual activation of LC16 neurons, which then turn on 5-HTPMPD neurons (serotonin neurons in the posterior medial dorsal cluster) and activate the release of serotonin; the latter inhibits P1 and plP10 neurons, thus turning off key hubs that are known to be activated during courtship. This allows flies to prioritize survival over reproduction.