Research SummaryCoding of innate olfactory preferences in the mosquito brain
Mosquitoes spread severe diseases such as malaria and dengue fever to hundreds of millions of people every year. These deadly insects detect humans using a variety of cues, including the exhaled carbon dioxide and skin odors. Recent work has succeeded in identifying the receptors and sensory neurons for salient chemicals including carbon dioxide and the repellent DEET. But we lack understanding about how the information relayed by the sensory neurons is processed in the mosquito brain and how it results in specific behavioral preferences. In this proposal, we will optimize the technique of in-vivo intracellular recordings for mosquitoes. By measuring the responses of projection neurons to attractive, repulsive and neutral odorants and examining their morphologies, we will test whether different attractive and repulsive odors are encoded by dedicated pathways. We will examine the anatomy and responses of local neurons in the antennal lobe to understand their contribution to the coding of behaviorally salient odors. We will also test how the output of the antennal lobe is represented in the higher olfactory centers in the mosquito brain. A mechanistic understanding of olfactory salience may help in future development of more effective olfaction-based strategies for mosquito control.
Figure Legend: Schematic of insect olfactory system. Olfactory receptor neurons (ORNs) detect odors and carry information into different glomeruli in the antennal lobe (AL). Local neurons (LNs) provide lateral connections between glomeruli. Projection neurons carry information from AL to the mushroom body (MB) and the lateral horn (LH).