Role of dopamine signaling in male courtship suppression induced by confinement stress in Drosophila.

Stress disturbs physiological and psychological homeostasis across species. In mammals, stress reduces male courtship motivation, but the underlying neuronal mechanisms remain poorly understood. Here, we establish a Drosophila model in which confinement to a small space without complete immobilization-termed small-space (SS) stress-suppresses male courtship behavior. Because stress modulates dopamine signaling in both vertebrates and invertebrates, we examined its role in SS-stress-induced courtship suppression. Pharmacological inhibition and genetic manipulations revealed that dopamine synthesis, release, and reception are required to maintain-but not initiate-the SS-stress-induced suppression of male courtship. Furthermore, dopamine release to and reception within the mushroom body-a brain region involved in higher-order sensory processing-were essential for sustaining courtship inhibition after stress. This SS stress paradigm provides a robust framework for elucidating dopamine-mediated mechanisms that support persistent behavioral changes after stress and contribute to a deeper understanding of the neurobiological basis of stress-related sexual dysfunction.