# Olfactory receptors and neurons regulating odor-guided behaviors in mosquitoes

> **NIH NIH R01** · JOHNS HOPKINS UNIVERSITY · 2022 · $520,167

## Abstract

Project Abstract/Summary
Anopheles gambiae mosquitoes, as the insect vector for the Plasmodium parasite that causes malaria,
were responsible for the deaths of >450,000 people last year. Fortunately, mosquitoes have a weakness
that our research aims to exploit. Mosquitoes use their sense of smell for most human host-seeking
behaviors. This suggests that targeting a mosquito's sense of smell could lead to effective measures that
prevent bites and the spread of diseases. Indeed, spatial repellents are volatile odorants that effectively
disrupt host-seeking behaviors and keep mosquitoes from approaching. They have widespread use in
developed nations as personal protective measures, but global adoption is limited due to high costs,
unwanted side-effects (such as skin irritation), or the need to use high-concentrations to remain
effective. A major limitation to the identification of new, more tractable, repellents is a lack of
understanding of how spatial repellents promote repulsion by impacting the mosquito's sense of smell.
This is primarily due to challenging technical hurdles needed to link repellent and other odorants to a
variety of olfactory neuron functions. Our introduction of the QF2/QUAS genetic binary system into
Anopheles mosquitoes overcomes previous technical barriers, and now enables us to directly visualize
the response of olfactory neurons, in living mosquitoes, to repellents and human body odors. Using a
combination of calcium imaging, single sensillum electrophysiological recordings, and RNA-seq along
with our established and novel genetic techniques, we will test the hypothesis that (1) spatial mosquito
repellents function by masking, activating, or scrambling the activity of olfactory neurons. We will
examine the activity patterns of olfactory neurons in living Anopheles gambiae mosquitoes when
stimulated by 20 commonly used mosquito repellents in the presence and absence of human odorants.
In addition, we will identify the odorant receptors expressed by olfactory neurons exhibiting altered
activity patterns in response to each repellent. Using a combination of genetic approaches (aimed at
modulating the function of targeted olfactory neurons) and behavioral assays, we will test the
hypothesis that (2) spatial repellents promote repellent behaviors by altering olfactory system
signaling. We will experimentally determine which olfactory neurons and what types of olfactory
neuron activity changes are either necessary and/or sufficient to drive repellent behaviors. The
proposed studies are significant because we will gain new mechanistic insights into how mosquito
repellents target the mosquito's sense of smell and enable the development of rationale biology-based
strategies to identify new repellents that are cheaper, safer, and more effective for use on a global scale
to prevent the spread of disease.

## Key facts

- **NIH application ID:** 10455031
- **Project number:** 5R01AI137078-05
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Christopher John Potter
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $520,167
- **Award type:** 5
- **Project period:** 2018-09-17 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10455031

## Citation

> US National Institutes of Health, RePORTER application 10455031, Olfactory receptors and neurons regulating odor-guided behaviors in mosquitoes (5R01AI137078-05). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10455031. Licensed CC0.

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