# Visual and olfactory integration in mosquito behavior

> **NIH NIH R21** · UNIVERSITY OF WASHINGTON · 2020 · $233,250

## Abstract

PROJECT SUMMARY
The goal of the proposed R21 project is to build on our recent discovery of olfactory “gating” of visual attraction
in Aedes aegypti mosquitoes, and specifically to unravel how odor modulates visual processing in the mosquito
brain to mediate attraction to visual objects, like features of a host. The sensory systems of mosquitoes play
key roles in mediating blood-feeding behaviors, as such, sensory systems provide attractive targets for
suppressing vector behaviors. Vision is a key sensory modality involved in long-range olfactory search
behaviors, as well as near-host behaviors involved in landing and biting. Despite this potential importance,
very little is known about vision in mosquitoes and the neural bases of these behaviors.
Mosquitoes can see a host from 5-15 m, and our recent findings show that vision plays a critical role in host
attraction by linking long-distance odor tracking with short-range behaviors near the host. Moreover, our
recent work utilizing a new Aedes GCaMP6s mosquito line – allowing both neuroanatomical identification and
characterization –, and generation of CRISPR dopamine receptor mutants, allowed us to determine how odor
information is processed in the brain and how neuromodulators influence this processing. Now, we seek to
build on these and preliminary findings that demonstrate the importance of neuromodulators in olfactory-visual
integration in mosquitoes. Using behavioral assays, calcium imaging in tethered flying mosquitoes, and
molecular-genetic approaches, we propose to study the visual preferences of Aedes mosquitoes, and how
olfactory input modulates visual neurons. Aim 1 will allow us to characterize the visual features that attract
mosquitoes and determine how long CO2 “turns on” visual search behaviors. We also take advantage of our
CRISPR Dop1 and Oct1 mutants to determine how olfactory-visual behaviors are compromised. Our
preliminary results indicate these neuromodulators are critical for the olfactory gating of visual responses. In
Aim 2 we will use our GCaMP6s mosquito line and two-photon microscopy to characterize how odor input
modulates neurons in the optic lobe (lobula). Pharmacological and genetic interventions of Oct1 and Dop1 will
allow us to further examine the importance of these pathways for sensitizing visual responses to attractive
objects.
While there has been extensive work on olfaction in mosquitoes, there is now increasing evidence that vision
also plays a key role. Moreover, olfactory-visual integration is important in diverse insect vectors, including
tsetse flies and kissing bugs. We suggest that our proposed experiments may provide a basic framework for
understanding how these cues influence behavior and sensory processing. Moreover, results from this work
can provide new information for utilizing additional visual cues in mosquito traps, as well as providing
motivation for the identification of molecular targets to cripple visual-olfactory behaviors.

## Key facts

- **NIH application ID:** 9932342
- **Project number:** 5R21AI137947-02
- **Recipient organization:** UNIVERSITY OF WASHINGTON
- **Principal Investigator:** Jeffrey A Riffell
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $233,250
- **Award type:** 5
- **Project period:** 2019-06-01 → 2021-05-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9932342

## Citation

> US National Institutes of Health, RePORTER application 9932342, Visual and olfactory integration in mosquito behavior (5R21AI137947-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9932342. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*
