Neural Basis of Odometry in Drosophila

Path integration is a mode of navigation in which travel distance and direction are integrated to calculate position. Estimating travel distance, or ‘odometry,’ requires the summation of translational vectors over time. Although neurons sensitive to translational velocity have been identified in numerous species, a definitive relationship between the activity of these translational velocity neurons and the subjective perception of distance has yet to be established. We developed a new memory-based assay to dissect the neural circuit of distance estimation. Flies can estimate distance by using self-motion, associate it with aversive stimulus onset, and use the PFN→hΔB pathway to estimate it. Thus, we provide evidence for self-motion integration for distance estimation in flies and point to the neural basis of this integration.