How specific sensory stimuli evoke specific behaviors is a fundamental problem in neurobiology. Most odorants elicit attraction or avoidance depending on their concentrations and identity, as well as the nature of the neural circuits they activate. Such odorants, moreover, typically activate combinations of olfactory sensory neurons (OSNs), complicating the dissection of the circuits translating odor recognition into behavior. Carbon dioxide (CO2), in contrast, elicits avoidance over a wide range of concentrations in the fly, Drosophila melanogaster, and activates only two populations of OSNs when examined by a sensitive, in vivo calcium imaging technique. Previous studies showed that OSNs expressing GR63a &GR21a receptors, the first CO2 olfactory neurons identified, is essential for avoidance to low concentrations of CO2, but it remained unclear the function of the other neurons activated by CO2. Here, we propose to determine that the putative 2nd CO2 OSNs and its cognate receptor that belongs to a member of the recently identified Ionotropic Glutamate Receptors (IRs) family are necessary and sufficient for detection of and avoidance to high CO2 concentrations and similar odorants such as acids. To address these questions, we will perform in vivo calcium imaging and behavioral assays. Determining subcellular localization of the 2nd CO2 receptor will predict whether or not the receptor directly interacts with odorants. To better understand central circuits mediating avoidance behavior, we will trace its projections into higher brain centers and compare them to the 1st CO2 pathway whether these two pathways converge upon a same target neuron in a higher brain center such as the lateral horn. Because CO2 and acids released by warm-blooded hosts are essential olfactory cues for the mosquito, and a homolog of the 2nd CO2 receptor is expressed in the mosquito antenna, we plan to examine whether the mosquito OSNs expressing the homolog are activated by CO2 and acids.

Public Health Relevance

Relevance Insects transmit diseases to humans and animals including livestock, and cause serious threats to health and enormous losses to agricultural output. Many insects respond to their human and animal hosts primarily through carbon dioxide (CO2) and lactic acid, key olfactory cues emanating from mammals. These olfactory cues activate defined populations of olfactory sensory neurons in the mosquito that express the same odorant receptors as in Drosophila. Understanding how the Drosophila sensory receptors are activated by CO2 and acids, and the mechanism by which their neural circuits trigger behavioral responses to these stimuli would help us develop better strategies to prevent transmission of insect-born diseases by mosquitoes, tsetse flies, and other pathogenic insects.

Agency
National Institute of Health (NIH)
Institute
National Institute of General Medical Sciences (NIGMS)
Type
Research Project (R01)
Project #
5R01GM089746-04
Application #
8517140
Study Section
Neurodifferentiation, Plasticity, and Regeneration Study Section (NDPR)
Program Officer
Sesma, Michael A
Project Start
2010-08-01
Project End
2015-11-30
Budget Start
2013-08-01
Budget End
2014-11-30
Support Year
4
Fiscal Year
2013
Total Cost
$283,352
Indirect Cost
$115,688
Name
New York University
Department
Anatomy/Cell Biology
Type
Schools of Medicine
DUNS #
121911077
City
New York
State
NY
Country
United States
Zip Code
10016
Park, Jin-Yong; Dus, Monica; Kim, Seonil et al. (2016) Drosophila SLC5A11 Mediates Hunger by Regulating K(+) Channel Activity. Curr Biol 26:1965-1974
Enjin, Anders; Zaharieva, Emanuela E; Frank, Dominic D et al. (2016) Humidity Sensing in Drosophila. Curr Biol 26:1352-8
Dus, Monica; Lai, Jason Sih-Yu; Gunapala, Keith M et al. (2015) Nutrient Sensor in the Brain Directs the Action of the Brain-Gut Axis in Drosophila. Neuron 87:139-51
Ai, Minrong; Mills, Holly; Kanai, Makoto et al. (2015) Green-to-Red Photoconversion of GCaMP. PLoS One 10:e0138127
Dus, Monica; Ai, Minrong; Suh, Greg S B (2013) Taste-independent nutrient selection is mediated by a brain-specific Na+ /solute co-transporter in Drosophila. Nat Neurosci 16:526-8
Min, Soohong; Ai, Minrong; Shin, Seul A et al. (2013) Dedicated olfactory neurons mediating attraction behavior to ammonia and amines in Drosophila. Proc Natl Acad Sci U S A 110:E1321-9
Enjin, Anders; Suh, Greg Seong-Bae (2013) Neural mechanisms of alarm pheromone signaling. Mol Cells 35:177-81
Ai, Minrong; Blais, Steven; Park, Jin-Yong et al. (2013) Ionotropic glutamate receptors IR64a and IR8a form a functional odorant receptor complex in vivo in Drosophila. J Neurosci 33:10741-9
Dus, Monica; Min, SooHong; Keene, Alex C et al. (2011) Taste-independent detection of the caloric content of sugar in Drosophila. Proc Natl Acad Sci U S A 108:11644-9
Ai, Minrong; Min, Soohong; Grosjean, Yael et al. (2010) Acid sensing by the Drosophila olfactory system. Nature 468:691-5