Mosquito brains encode unique features of human odour to drive host seeking

• Published in: Nature (London) 2022-05, Vol.605 (7911), p.706-712
• Main Authors: Zhao, Zhilei, Zung, Jessica L., Hinze, Annika, Kriete, Alexis L., Iqbal, Azwad, Younger, Meg A., Matthews, Benjamin J., Merhof, Dorit, Thiberge, Stephan, Ignell, Rickard, Strauch, Martin, McBride, Carolyn S.
• Format: Article
• Language: English
• Subjects: 14; 14/1; 14/19; 14/69; 45/41; 631/378/2624; 631/378/3917; 631/601/1466; 631/92/604; 64; Aedes - physiology; Aedes aegypti; Aldehydes; Animals; Antennal lobe; Aquatic insects; Biochemistry and Molecular Biology; Biokemi och molekylärbiologi; Brain - physiology; Female; Females; Glomerulus; Host searching behavior; Host-Seeking Behavior; Humanities and Social Sciences; Humans; Lipids; Mixtures; Mosquito Control; Mosquito Vectors - physiology; Mosquitoes; multidisciplinary; Neural coding; Neurons; Neurosciences; Neurovetenskaper; Odorants; Odors; Olfactory discrimination; Olfactory discrimination learning; Olfactory glomeruli; Science; Science (multidisciplinary); Vertebrates; Wind tunnels
• ISSN: 0028-0836; 1476-4687; 1476-4687
• DOI: 10.1038/s41586-022-04675-4

A globally invasive form of the mosquito Aedes aegypti specializes in biting humans, making it an efficient disease vector 1 . Host-seeking female mosquitoes strongly prefer human odour over the odour of animals 2 , 3 , but exactly how they distinguish between the two is not known. Vertebrate odours are complex blends of volatile chemicals with many shared components 4 – 7 , making discrimination an interesting sensory coding challenge. Here we show that human and animal odours evoke activity in distinct combinations of olfactory glomeruli within the Ae. aegypti antennal lobe. One glomerulus in particular is strongly activated by human odour but responds weakly, or not at all, to animal odour. This human-sensitive glomerulus is selectively tuned to the long-chain aldehydes decanal and undecanal, which we show are consistently enriched in human odour and which probably originate from unique human skin lipids. Using synthetic blends, we further demonstrate that signalling in the human-sensitive glomerulus significantly enhances long-range host-seeking behaviour in a wind tunnel, recapitulating preference for human over animal odours. Our research suggests that animal brains may distil complex odour stimuli of innate biological relevance into simple neural codes and reveals targets for the design of next-generation mosquito-control strategies. Select chemical compounds enriched in human odour activate an olfactory glomerulus in the brain of Aedes aegypti mosquitoes, which strengthens host-seeking behaviour and helps explain their strong preference for biting humans.