Exploring the Asymmetric Body's Influence on Interval Timing Behaviors of Drosophila melanogaster

The roles of brain asymmetry in Drosophila are diverse, encompassing the regulation of behavior, the creation of memory, neurodevelopment, and evolution. A comprehensive examination of the Drosophila brain has the potential to enhance our understanding of the functional significance of brain asymmetry in cognitive and behavioral processes, as well as its role in evolutionary perspectives. This study explores the influence of brain asymmetry on interval timing behaviors in Drosophila, with a specific focus on the asymmetric body (AB) structure. Despite being bilaterally symmetric, the AB exhibits functional asymmetry and is located within the central complex of the fly brain. Interval timing behaviors, such as rival-induced prolonged mating duration: longer mating duration behavior (LMD) and sexual experience-mediated shorter mating duration behavior (SMD), are essential for Drosophila. We utilize genetic manipulations to selectively activate or inhibit AB neurons and evaluates their impact on LMD and SMD behaviors. The results indicate that specific populations of AB neurons play unique roles in orchestrating these interval timing behaviors. Notably, inhibiting GAL4^R38D01-labeled AB neurons disrupts both LMD and SMD, while GAL4^R42C09 neuron inhibition affects only LMD. Moreover, hyperexcitation of GAL4^R72A10-labeled AB neurons perturbs SMD. Our study identifies NetrinB (NetB) and Abdominal-B (Abd-B) are important genes for AB neurons in LMD and highlights the role of 5-HT1B neurons in generating LMD through peptidergic Pigment-dispersing factor (PDF) signaling. In summary, this study underscores the importance of AB neuron asymmetry in mediating interval timing behaviors and provides insights into the underlying mechanisms of memory formation and function in Drosophila.