A neural circuit for wind-guided olfactory navigation

Abstract

To navigate towards a food source, animals must frequently combine odor cues that tell them what sources are useful with wind direction cues that tell them where the source can be found. Where and how these two cues are integrated to support navigation is unclear. Here we identify a pathway to the Drosophila fan-shaped body (FB) that encodes attractive odor and promotes upwind navigation. We show that neurons throughout this pathway encode odor, but not wind direction. Using connectomics, we identify FB local neurons called h{Delta}C that receive input from this odor pathway and a previously described wind pathway. We show that h{Delta}C neurons exhibit odor-gated, wind direction-tuned activity, that sparse activation of h{Delta}C neurons promotes navigation in a reproducible direction, and that h{Delta}C activity is required for persistent upwind orientation during odor. Based on connectome data, we develop a computational model showing how h{Delta}C activity can promote navigation towards a goal such as an upwind odor source. Our results suggest that odor and wind cues are processed by separate pathways and integrated within the FB to support goal-directed navigation.