Odor tracking in flying <i>Drosophila</i> requires visual reafference and compass neurons

A crucial brain function that remains largely mysterious is building robust working memory by integrating stimuli across sensory modalities. For flying <i>Drosophila</i> , visual feedback is required to localize an odor source. Recently, a group of cells residing in the navigation center of the fly brain (E-PG neurons) have been shown to function like an internal compass, providing a dynamic working memory of heading changes akin to mammalian head-direction cells. Here, we show that self-generated visual motion signals work with E-PG compass neurons so that the direction of exploratory turns can be stored and recalled to maintain the animal's heading within an odor plume during flight.