Mosquito brains wired for our discovery

a mosquito bite, It’s annoying. It often causes itching. But in some parts of the world, the situation is much worse than that. What do scientists call it? Aedes aegypti now considered main vector subordinate dengue fevervirus ZikaThe Chikungunya And from here yellow fever. We understand why scientists are looking for solutions that can save us from its sting.

The problem is, moreover, that this particular mosquito has developed a tendency to bite humans almost exclusively. Does this mean that he knows how to distinguish the smell of humans from the smell of other mammals? sound. And after years of effort, Princeton University researchers (US) think they finally understood how, thanks high-definition pictures The brain mosquitoes;

It wasn’t easy. Scholars from different backgrounds participated. The researchers first had to design genetically modified mosquitoes whose brain lights up when it’s active. Two years of work. Then they had to make them smell the scents of human beings – recovered by taking care not to contaminate them with the scent of the fibers of our clothes – and animals – which are restored with the greatest precautions of hair in particular, which are taken here on mice, sheep, guinea pigs or even dogs – in the hope of noticing Differences in reaction in the aforementioned mosquitoes. Once again, two years of work to develop a system that effectively diffuses these scents. Time, still, to build an imaging system suitable for studying the mosquito brain. But everything seems to be rewarded today.

Incredibly simple mechanism

To understand this, remember that mammalian odors – including our own – are made up of dozens of different compounds. complex mixture. So to distinguishhuman smell Of the animals, scientists think mosquitoes must have evolved a complex mechanism. That’s why they wanted to drill into their brains.

And be surprised! The mosquito actually makes use of a surprisingly simple mechanism to target its prey. Of the 60 nerve centers—scientists call them glomeruli—that mosquitoes have, only two are present. The first as a launcher Alert, indicates nearby smells, regardless of those smells. The second is responsible for confirming – or not – that it is a human scent.

Two also is the number of compounds in our scent that seem to matter to mosquitoes. Researchers have also identified them: decanal – with the formula CH₃ (CH₂) ₈CHO – and undecanal – with the formula C₁₀H₂₁CHO. They’ve already patented a deca-containing mixture that they hope will result in baits that lure mosquitoes into deadly traps or repellents that cut their signals.