Navigation in Drosophila melanogaster: insights from experiments on freely walking flies

Abstract: This thesis describes my investigation of navigation in Drosophila melanogaster, specifically focusing on path integration and responses to visual stimuli in freely walking flies. The primary goal was to understand how flies use internal and external cues to navigate, leveraging the genetic tools and recent advancements in neural circuit research of the fly compass system. I conducted behavioral experiments with freely walking flies in relatively large spaces, providing a more naturalistic environment compared to commonly used tethered setups, where a fly walks on an air-supported ball. While tethered setups allow neural activity monitoring, freely walking setups used here make it possible to study more ethologically relevant behaviors. The analysis of the presented experiments centered primarily on the characterization of the flies’ walking trajectories.
Initially, I investigated the ability of flies to use path integration, a navigational strategy for returning to previously visited locations. Our published study provides strong evidence of the ability of walking flies to perform path integration in darkness to navigate back to a location associated with food reward while highlighting that other strategies, such as pheromone deposition, may also contribute to this navigational process. Our finding implies that the flies are capable of accumulating walked directions and distances relying on self-motion idiothetic cues.
However, when I implemented a similar experimental approach, this time providing flies with visual directional cues, such as linearly polarized light or a simulated moon, the outcomes diverged from those in darkness. These cues were expected to provide a directional reference and potentially reduce the accumulated error of path integration. Nevertheless, the flies did not consistently demonstrate robust return behavior, which complicated the task of accurately assessing the role of directional cues in path integration vector computation. In the thesis, I discuss potential improvements to these experiments to achieve more conclusive results.
My subsequent research aimed to gain more understanding of how the brain processes directional cues. I aimed to evaluate the role of the neural pathways leading to the central complex (CX), a region known as the navigational center in the insect brain, in shaping behavioral responses to the directional cues I used in the previous experiments. In particular, I explored the impact of silencing compass neurons and their polarization-sensitive inputs on the flies’ alignment with linearly polarized light. This investigation led to some unexpected results. Perturbing the activity of the compass neurons and their primary polarization inputs using a genetic silencing technique affected alignment in opposite ways. Moreover, silencing of another pathway leading to the compass neurons occasionally resulted in a perpendicular direction choice during the early stages of exposure to polarized light. These outcomes call for further research to find responsible physiological mechanisms.
The experimental approaches established in this thesis contribute to our knowledge of navigation in freely moving Drosophila and offer adaptable methodologies for future studies in insect navigation and beyond

Object Details

• Location: Deutsche Nationalbibliothek Frankfurt am Main
• Extent: Online-Ressource
• Language: Englisch
• Notes: Universität Freiburg, Dissertation, 2024

Classification and Topics

• Keyword: Taufliege ; Drosophila ; Navigation ; Neuroethologie

Contributors, Places and Time

• Event: Veröffentlichung
• (where): Freiburg
• (who): Universität
• (when): 2024
• Creator: Titova, Anna
• Contributor: Straw, Andrew D. ; Wernet, Mathias F. ; Leibold, Christian ; Albert-Ludwigs-Universität Freiburg. Institut für Biologie I (Zoologie) ; Albert-Ludwigs-Universität Freiburg. Fakultät für Biologie

Further information

• DOI: 10.6094/UNIFR/251444
• URN: urn:nbn:de:bsz:25-freidok-2514445
• Rights: Open Access; Der Zugriff auf das Objekt ist unbeschränkt möglich.
• Last update: 14.08.2025, 10:44 AM CEST