At best, mosquito bites are annoying. At worst, they result in the spread of a number of diseases, ranging from malaria to yellow fever to the Zika virus. In many cases, these diseases cannot be vaccinated and treatment may be out of reach for populations in places where they are endemic.
However, researchers at Johns Hopkins University recently made a possible breakthrough in understanding just what makes us such attractive meals for mosquitoes — and, potentially, how “changing our flavor” could help stop it.
“Surprisingly, we know very little about how mosquito repellants actually work; that is, how they mess up the mosquito’s sense of smell,” Christopher Potter, assistant professor of neuroscience at the Johns Hopkins School of Medicine, told Digital Trends. “This is because it has previously been technically very difficult to make connections between a repellant and what it does to the mosquito’s sense of smell. Our new work changes all that.”
What the researchers have done is to create, for the first time, a method for genetically labeling the majority of the olfactory (read: smell) neurons in the Anopheles mosquito. Genetically labeling those neurons means generating new mosquito strains in which the smell neurons express a special glowing green fluorescent protein — thereby allowing the neurons to be viewed in unprecedented detail.
“What I find most exciting is that we’ve discovered something new about how the ‘nose’ of the mosquito connects to the brain, which gives us some insights into what the mosquito might be ‘thinking’ when it smells us,” Potter continued. “Mosquitoes have three noses: the antenna, the maxillary palp, and the labella. We are studying the neurons in these three noses, and where those neurons go to in the mosquito brain.”
Interestingly, the part of the brain the researchers were able to track the nose neurons to was an area called the subesophageal zone.
“This is a region of the insect brain that has never before been implicated in the sense of smell,” Potter said. “Before it had only been implicated with the sense of taste. What this suggests is that there is a region of the mosquito brain that might be combining both smell and taste. In our brains, this combination gives rise to the perception of flavor, so maybe there is a region of the mosquito brain that is also acting as [a] ‘human flavor’ center.”
Identifying this “human flavor” will be the next step of the work. “We are really interested in using our discoveries to identify better insect repellants,” Potter said.
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