Drosophila re-zero their path integrator at the center of a fictive food patch
The ability to keep track of one's location in space is a critical behavior for animals navigating to and from a salient location, and its computational basis is now beginning to be unraveled. Here, we tracked flies in a ring-shaped channel as they executed bouts of search triggered by optogenetic activation of sugar receptors. Unlike experiments in open field arenas, which produce highly tortuous search trajectories, our geometrically constrained paradigm enabled us to monitor flies' decisions to move toward or away from the fictive food. Our results suggest that flies use path integration to remember the location of a food site even after it has disappeared, and flies can remember the location of a former food site even after walking around the arena one or more times. To determine the behavioral algorithms underlying Drosophila search, we developed multiple state transition models and found that flies likely accomplish path integration by combining odometry and compass navigation to keep track of their position relative to the fictive food. Our results indicate that whereas flies re-zero their path integrator at food when only one feeding site is present, they adjust their path integrator to a central location between sites when experiencing food at two or more locations. Together, this work provides a simple experimental paradigm and theoretical framework to advance investigations of the neural basis of path integration.
© 2021 Elsevier Inc. Received 21 January 2021, Revised 12 July 2021, Accepted 2 August 2021, Available online 26 August 2021. We would like to thank all members of our lab for helpful discussions. Will Dickson provided essential help with programming and construction of our experimental set-up. Research reported in this publication was supported by the National Institute of Neurological Disorders and Stroke of the NIH (U19NS104655). Author contributions: A.H.B. conducted all experiments, under the supervision of M.H.D. E.H.P. developed the state-based models of behavior. A.H.B., E.H.P., and R.A.C. analyzed data and prepared all figures. A.H.B., E. H. P., R.A.C., and M.H.D. wrote the paper. The authors declare no competing interests. Data and code availability: All data have been deposited at Mendeley Data: https://dx.doi.org/10.17632/tn2fb6hwmp.1 and are publicly available as of the date of publication. The DOI is listed in the Key resources table. All original code for data analysis has been deposited at Mendeley Data: https://dx.doi.org/10.17632/tn2fb6hwmp.1 and is publicly available as of the date of publication. All original code used for machine vision and tracking is publicly available on Github: http://florisvb.github.io/multi_tracker. The DOIs are listed in the Key resources table. Any additional information required to reanalyze the data reported in this paper is available from the lead contact upon request.
Supplemental Material - 1-s2.0-S0960982221011088-mmc1.pdf
Submitted - 2021.01.18.427191v2.full.pdf
Accepted Version - nihms-1736810.pdf