Optimising virtual reality for visual behaviour experiments in tethered walking flies

Abstract

When shown a rotating grating pattern, Drosophila melanogaster moves in the direction of the pattern. This is known as the optomotor response. It is a robust response and has been observed over multiple experimental conditions. Here, I use the robust optomotor response to replicate the optomotor responses of the flies on an inexpensive fly-on-ball setup. I also characterise the intensity of the stimuli at which flies show optomotor responses on the setup. The characterisation of the setup increases the replicability of experiments by having multiple fly-on-ball setups using a low budget. Experimenters have used virtual reality environments to solve neuroscience problems. LED arenas and projectors have been used to show virtual reality environments to study behaviour. Here, I used a single tablet to stimulate flies visually and study their responses on the inexpensive setup. I attempted to optimise the virtual reality of two tablets to replicate optomotor experiments on the inexpensive fly-on-ball setup. This increases the field of view of the stimuli on the fly eye and opens up a repertoire of experiments that researchers can do on inexpensive setups to study visual circuitry. In the single tablet setup, I obtained symmetric responses in the case when I placed the tablet in the front and asymmetric responses when I placed it at the side of the fly. In the two-tablet setup, I obtained asymmetric responses where I expected symmetric responses and vice versa.