Visual Abstract
Abstract
Contrast enhancement mediated by lateral inhibition within the nervous system enhances the detection of salient features of visual and auditory stimuli, such as spatial and temporal edges. However, it remains unclear how mechanisms for temporal contrast enhancement in the olfactory system can enhance the detection of odor plume edges during navigation. To address this question, we delivered to Drosophila melanogaster flies pulses of high odor intensity that induce sustained peripheral responses in olfactory sensory neurons (OSNs). We use optical electrophysiology to directly measure electrical responses in presynaptic terminals and demonstrate that sustained peripheral responses are temporally sharpened by the combined activity of two types of inhibitory GABA receptors to generate contrast-enhanced voltage responses in central OSN axon terminals. Furthermore, we show how these GABA receptors modulate the time course of innate behavioral responses after odor pulse termination, demonstrating an important role for temporal contrast enhancement in odor-guided navigation.
Footnotes
The authors declare no competing financial interests.
Work in the laboratory of M.N.N. was supported in part by the National Institute of Neurological Disorders and Stroke, the National Institutes of Health (NIH; Grants R01-NS-055035, R01-NS-056443, and R01-NS-091070); the National Institute of General Medical Sciences (NIGMS), NIH (Grant R01GM098931); and the Kavli Institute for Neuroscience. L.Y.M. was supported by a Gruber Science Fellowship and NIGMS, NIH (Grant T32GM007223).
This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International, which permits unrestricted use, distribution and reproduction in any medium provided that the original work is properly attributed.
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