# Characterizing odor motion detection in flies

> **NIH NIH RF1** · YALE UNIVERSITY · 2023 · $1,887,897

## Abstract

Many animals rely on their ability to navigate to the source of airborne odor plumes for survival. Studies dating
back a century have shown that insects combine mechanosensory and olfactory cues to navigate, surging
upwind when detecting odor but go crosswind or downwind when losing the signal. They also use bilateral
information from their two antennae to turn toward higher odor concentrations. We recently discovered that in
addition to wind direction and odor gradient, fruit flies detect the direction of motion of odors, independent of the
wind. Using optogenetics to decouple odor signal from wind, we found that flies detect odor motion using the
temporal correlations of the odor signal between their two antennae, suggesting similarities with motion detection
in vision. Manipulating spatio-temporal correlations in virtual odor signals demonstrated that flies indeed exploit
odor motion when navigating odor plumes.
The finding that Drosophila melanogaster can ‘smell’ odor motion suggests a novel role for bilateral sensing in
olfaction and raises the following questions for the field: 1) How is odor motion — a previously unappreciated
olfactory directional cue — integrated with other directional cues to drive olfactory navigation? 2) What are the
inputs to the odor motion detector and how does odor valence modulate behavioral response to odor motion? 3)
What neural circuits and computations mediate odor motion detection and how do they compare to those that
mediate visual motion detection? We will address these questions by combining optogenetic stimulation, neuron
activity measurements, and neurogenetic silencing with the behavioral and computational framework we used
to discover odor motion sensing. With this platform we can control, measure, and perturb real odor and virtual
odor signals in closed- and open-loop, during olfactory navigation of freely walking flies. Drosophila is perfectly
suited to pursue these goals because of 1) the current knowledge of the neural circuit of the olfactory periphery
and increasingly of downstream olfactory centers, and the availability of a connectome; and (2) the ability to
selectively measure and manipulate the activity of neural circuits involved in sensory processing and integration.
The finding that flies use odor motion detection to enhance odor-guided navigation reveals important gaps in our
understanding of olfactory navigation. The proposed research will close these gaps by characterizing how flies
integrate odor motion with other cues to direct olfactory behavior, and by uncovering the neural circuits and
computations that mediate odor motion detection. More broadly, these findings will advance our understanding
of neuronal circuit computations by allowing us to compare circuits that compute motion across the modalities of
olfaction and vision, which derive these signals from inputs with very different statistics and use them for different
navigational purposes.

## Key facts

- **NIH application ID:** 10717167
- **Project number:** 1RF1NS132840-01
- **Recipient organization:** YALE UNIVERSITY
- **Principal Investigator:** Damon Alistair Clark
- **Activity code:** RF1 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2023
- **Award amount:** $1,887,897
- **Award type:** 1
- **Project period:** 2023-08-01 → 2026-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10717167

## Citation

> US National Institutes of Health, RePORTER application 10717167, Characterizing odor motion detection in flies (1RF1NS132840-01). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10717167. Licensed CC0.

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