Meeting Abstract
Animals, including Drosophila Melanogaster (fruit flies), can keep track of their position using both cues generated by its movement (idiothetic cues), as well as external cues such as a landmark movement (allothetic cues). How fruit flies use allothetic cues such as vision and mechanosensory cues is relatively well understood. However, their ability to navigate based on idiothetic cues is underexplored. Therefore, we created a new behavioral paradigm to explore the use of idiothetic cues in navigation. In this behavior, a group of olfactory neurons which signal the presence of an attractive odor are optogenetically activated (using a red light) in a small region of the arena. Activation of the olfactory neurons result in the flies repeatedly visiting the location where the neurons are activated. By employing different arena sizes, different spatio-temporal configuration of the activation-zone we were able to understand the capacity of the flies to navigate using idiothetic cues alone. To further understand the principles underlying this navigation, we have replicated the same experimental design using a tethered fly on a trackball. Using its fictive trajectory, we will activate the same group of olfactory neurons when it is at a given position. A comparison of its performance on the trackball versus in freely walking animals will provide further insight into this problem. Finally, we will compare the search kinematics of flies in the ring assay to that of the flies on the trackball to determine the locomotive alterations of the searching fly while walking on a trackball.
