New modular assays for the quantitative study of skylight navigation in flying flies

Abstract

The quantitative study of visual behaviors using virtual flight arenas is complicated by the fact that an effective experimental setup needs to combine a rather complex set of custom-built mechanical, electronic, and software components. Assembling such an apparatus amounts to a major challenge when working in an environment without the support of a machine shop. Here we present detailed instructions for the assembly of virtual flight arenas optimized for Drosophila skylight navigation, which can easily be modified towards other uses. This system consists entirely of off-the-shelf parts and 3D-printed components, combining a modular flight arena designed to reduce visual artifacts, swappable high-power LED light sources, polarization filters on a computer-controlled rotating filter wheel, all placed within a temperature and humidity controlled environment. Using this new assay, we show that individual flies choose arbitrary headings when flying under a uniform field of linear polarization. Furthermore, flies adjust their heading to both sudden and continuous changes in filter orientation and can keep their chosen heading for several minutes. Finally, flies show the tendency to maintain headings even after interruption with an unpolarized stimulus. Taken together, these findings demonstrate the usefulness of these assays for the study of skylight navigation in flies.