An internal expectation guides Drosophila egg-laying decisions
Abstract
When presented with two egg-laying substrates, Drosophila lay most of their eggs on the option with higher relative value. How do flies make this relative-value decision? Might the strategy they use allow them to choose the best option even when they experience substrates with a more complex spatiotemporal profile than in canonical two-choice paradigms? We measured Drosophila egg-laying behavior in diverse substrate environments. In all cases, we found that flies dynamically increase or decrease their egg-laying rates as they explore substrates for a deposition site so as to target eggs to the best, recently visited option. Visiting the best option typically led to a strong reduction in egg laying on other substrates for several minutes, with this timescale varying across fly strains. Our data support a model in which flies compare the value of the current substrate with an internally constructed expectation on the value of available options to regulate the likelihood of laying an egg. We show that dopamine-neuron activity is critical for learning and/or expressing this expectation, similar to its role in certain tasks in vertebrates. Integrating sensory experiences over minutes to generate an internal sense of the quality of available options, i.e., forming an expectation, allows flies to use a dynamic reference point for judging the current substrate and might be a general way in which decisions are made, even beyond flies and egg laying.
Additional Information
The copyright holder for this preprint is the author/funder, who has granted bioRxiv a license to display the preprint in perpetuity. It is made available under a CC-BY 4.0 International license. This version posted October 2, 2021. We thank the Rockefeller University Precision Instrumentation Technologies facility for access to fabrication equipment; the Bloomington Drosophila Stock Center (NIH P400D018537), Li Zhao, Sylvia Durkin, Wanhe Li, Nilay Yapici, John Tuthill, Karla Kuan, and Mark Wu for fly stocks; Atsuko Adachi for help immunostaining many of the screened lines; and Nivedita Rangarajan, Sam Cohen, and Sylvia Durkin for assistance with experiments. Research reported in this publication was supported by a Brain Initiative grant from the National Institute of Neurological Disorders and Stroke (R01NS121904) to G.M. and Leon Levy Foundation fellowship and the Kavli Neural Systems Institute grant to V.V.. G.M. is a Howard Hughes Medical Institute Investigator. Data Analysis Software: All data analyses were done using MATLAB (MathWorks). Author Contributions: V.V. and G.M. conceived the initial study and wrote the manuscript. V.V., with input from G.M., designed the experiments, performed the experiments, analyzed the data, interpreted the results, and decided on new experiments. Z.W., V.C., A.C., R.L., and S.L.S. assisted with performing various egglaying experiments and interpreting the results. H.A. developed code to markedly speed up manual annotation of egg-deposition events. The authors declare no competing interests.Attached Files
Submitted - 2021.09.30.462671v1.full.pdf
Supplemental Material - media-1.mp4
Supplemental Material - media-2.mp4
Supplemental Material - media-3.mp4
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Additional details
- Eprint ID
- 111224
- Resolver ID
- CaltechAUTHORS:20211005-212336712
- P400D018537
- NIH
- R01NS121904
- NIH
- Leon Levy Foundation
- Kavli Neural Systems Institute
- Howard Hughes Medical Institute (HHMI)
- Created
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2021-10-05Created from EPrint's datestamp field
- Updated
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2021-11-16Created from EPrint's last_modified field