Synaptic targets of photoreceptors specialized to detect color and skylight polarization in Drosophila
Color and polarization provide complementary information about the world and are detected by specialized photoreceptors. However, the downstream neural circuits that process these distinct modalities are incompletely understood in any animal. Using electron microscopy, we have systematically reconstructed the synaptic targets of the photoreceptors specialized to detect color and skylight polarization in Drosophila, and we have used light microscopy to confirm many of our findings. We identified known and novel downstream targets that are selective for different wavelengths or polarized light, and followed their projections to other areas in the optic lobes and the central brain. Our results revealed many synapses along the photoreceptor axons between brain regions, new pathways in the optic lobes, and spatially segregated projections to central brain regions. Strikingly, photoreceptors in the polarization-sensitive dorsal rim area target fewer cell types, and lack strong connections to the lobula, a neuropil involved in color processing. Our reconstruction identifies shared wiring and modality-specific specializations for color and polarization vision, and provides a comprehensive view of the first steps of the pathways processing color and polarized light inputs.
All data generated or analyzed during this study are included in the manuscript and supporting files. Supplementary File 1 and 3 contain all connectivity data. Supplementary File 2 provides images of all EM skeletons.All code and necessary data to perform the analysis and generate the figures of this manuscript will be available from https://github.com/reiserlab.All reconstructed neurons described in the manuscript will be made available at https://fafb.catmaid.virtualflybrain.org/.
Article and author information
Howard Hughes Medical Institute
- Kit D Longden
- Aljoscha Nern
- Arthur Zhao
- Miriam A Flynn
- Connor W Laughland
- Bruck Gezahegn
- Henrique DF Ludwig
- Alex G Thomson
- Heather Dionne
- Davi D Bock
- Gerald M Rubin
- Michael B Reiser
Freie Universität Berlin
- Emil Kind
- Gizem Sancer
- Tessa Obrusnik
- Paula G Alarcón
- Mathias F Wernet
Deutsche Forschungsgemeinschaft (WE 5761/2-1)
- Mathias F Wernet
Deutsche Forschungsgemeinschaft (WE 5761/4-1)
- Mathias F Wernet
Air Force Office of Scientific Research (FA9550-19-1-7005)
- Mathias F Wernet
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
- Ronald L Calabrese, Emory University, United States
- Preprint posted: May 17, 2021 (view preprint)
- Received: July 1, 2021
- Accepted: December 15, 2021
- Accepted Manuscript published: December 16, 2021 (version 1)
- Accepted Manuscript updated: January 4, 2022 (version 2)
- Version of Record published: January 25, 2022 (version 3)
© 2021, Kind et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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- Developmental Biology
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