Computations underlying Drosophila photo-taxis, odor-taxis, and multi-sensory integration
Abstract
To better understand how organisms make decisions on the basis of temporally varying multi-sensory input, we identified computations made by Drosophila larvae responding to visual and optogenetically induced fictive olfactory stimuli. We modeled the larva's navigational decision to initiate turns as the output of a Linear-Nonlinear-Poisson cascade. We used reverse-correlation to fit parameters to this model; the parameterized model predicted larvae's responses to novel stimulus patterns. For multi-modal inputs, we found that larvae linearly combine olfactory and visual signals upstream of the decision to turn. We verified this prediction by measuring larvae's responses to coordinated changes in odor and light. We studied other navigational decisions and found that larvae integrated odor and light according to the same rule in all cases. These results suggest that photo-taxis and odor-taxis are mediated by a shared computational pathway.
Article and author information
Author details
Reviewing Editor
- Ronald L Calabrese, Emory University, United States
Version history
- Received: December 22, 2014
- Accepted: May 5, 2015
- Accepted Manuscript published: May 6, 2015 (version 1)
- Version of Record published: June 16, 2015 (version 2)
Copyright
© 2015, Gepner et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Further reading
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- Computational and Systems Biology
- Neuroscience
Three recent studies use optogenetics, virtual ‘odor-scapes’ and mathematical modeling to study how the nervous system of fruit fly larvae processes sensory information to control navigation.
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- Biochemistry and Chemical Biology
- Neuroscience
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