Visually Mediated Odor Tracking During Flight in Drosophila
Summary
Here we describe how to optimize the acquired video image for an olfactory magnetic-tether (OMT) apparatus. We also describe two sample experimental protocols for studying visuo-olfactory fusion.
Abstract
Flying insects use visual cues to stabilize their heading in a wind stream. Many animals additionally track odors carried in the wind. As such, visual stabilization of upwind tracking directly aids in odor tracking. But do olfactory signals directly influence visual tracking behavior independently from wind cues? Additionally, recent advances in olfactory molecular genetics and neurophysiology have motivated novel quantitative behavioral analyses to assess the behavioral influence of (e.g.) genetically inactivating specific olfactory activation circuits. We modified a magnetic tether system originally devised for vision experiments by equipping the arena with narrow laminar flow odor plumes. Here we focus on experiments that can be performed after a fly is tethered and is able to navigate in the magnetic arena. We show how to acquire video images optimized for measuring body angle, how to judge stable odor tracking, and we illustrate two experiments to examine the influence of visual cues on odor tracking.
Protocol
Discussion
The image acquisition for this system utilizes an inexpensive firewire board camera and software written in Matlab. Clear images are crucial for obtaining accurate data traces. The strategies described above are useful for cleaning up images in this system. Other video tracking procedures for this system have been described 1. Furthermore, this system could easily be modified to include real-time video tracking. The example experimental protocols described here meant to be a starting point to ensure the proper…
Acknowledgements
Funded by a grant from the National Science Foundation to MF
Materials
| Material Name | Type | Company | Catalogue Number | Comment |
|---|---|---|---|---|
| Firewire camera | 1394store.com | Fire-I board camera BW | 4.3mm lens no IR coating | |
| IR LEDs | Small Parts | |||
| Black spray paint | Rustoleum | Flat black | ||
| Black flock paper | Edmund Scientific | |||
| Panel system | Caltech | 3 | ||
| Matlab 2006a | Mathworks | Image acquisition toolbox |
References
- Bender, J. A., Dickinson, M. Visual stimulation of saccades in magnetically tethered Drosophila. J Exp Biol. 209, 3170-3182 (2006).
- Duistermars, B. J., Frye, M. A. Crossmodal visual input for odor tracking during fly flight. Curr Biol. 18, 270-275 (2008).
- Reiser, M. B., Dickinson, M. A modular display system for insect behavioral neuroscience. J Neurosci Methods. 167, 127-139 (2008).
- Götz, K. G. Course-control, metabolism and wing interference during ultralong tethered flight in Drosophila melanogaster. J. Exp. Biol. 128, 35-46 (1987).
