Sexually dimorphic neuronal circuits underlying social behaviours in Drosophila

ended

Sex differences are basic for reproduction, parenting and other social interactions. Pheromone secretions that are differentially perceived by males and females, release stereotypical behaviours in many species. I will study how simple connectivity switches in a Drosophila sexually-dimorphic neuronal circuit are assembled into complex networks, from sensory processing to behavioural control. 11-cis-Vaccenyl-acetate (cVA) is a male-pheromone eliciting sex-specific responses: attracts females and repels males. Sex-specific wiring of olfactory neurons reroutes cVA information, forming a developmental switch in information flow. Central aSP-g neurons receive cVA innervation in females but not males, while this cluster is implicated in male-male aggressive behaviour. The role of aSP-g in social interactions was not compared between sexes, and that is my first aim. Next, I will find input and output neurons of aSP-g neurons in both sexes, by combining state-of-the-art anatomical, physiological and behavioural methodology: in-silico circuit-tracing methods to find neurons with overlapping innervations to aSP-g; and a unique electron-microscopy volume scan of a female brain to reconstruct aSP-g neurons and their synaptic partners. I will validate functional connectivity using photoactivation of output neurons while calcium-imaging target neurons. I aim to discover how sexually-specific wiring differences in homologous circuits regulate sexually-dimorphic social behaviours. These basic neuronal connectivity motifs may be conserved beyond flies.