THE ESSENTIAL
- Researchers Have Identified How Mosquitoes’ Brains Code Human Scent to Spot Us
- Diseases transmitted by these insects affect several hundred million people a year
What makes us the unfortunate victims of the most dangerous mosquitoes? This is the question that scientists from Princeton University in the United States have looked into. Indeed, certain strains of Aedes aegypti, which sows death in regions prone to Zika and dengue fever, depend on us to survive and have had to develop incredibly precise targeting strategies. Accurate and efficient: the mosquito kills every year 725,000 people in front of the man who claims 475,000 victims.
Simple mechanism
“We sought to understand how these mosquitoes distinguish between human and animal odors both in terms of the human scent they pick up on and the part of their brains that allows them to detect these signals.“, describes expert Carolyn “Lindy” McBride, assistant professor of ecology and evolutionary biology and neurosciences, in the study published in the journal Nature.
Once the many technical challenges have been met – recovering human and animal odors non-destructively, designing a system to “blow human odor” onto mosquitoes in an imaging device, creating a wind tunnel to test simple mixtures or unique compounds, and breeding viable strains of mosquitoes whose brains react to the material – they began collecting data that revealed the simplicity of the mechanism these mosquitoes used to recognize us.
“Despite the complexity of human scent, and the fact that it doesn’t really contain any human-specific compounds, mosquitoes have evolved a surprisingly simple mechanism to recognize us.”, according to Carolyn “Lindy” McBride.
60 nerve centers
The mosquito brain has 60 nerve centers called glomeruli. The team had speculated that many of them – maybe even most – would be involved in helping these human-dependent mosquitoes find their favorite food.
However, only two glomeruli were involved. Of the two nerve centers, one reacts to many smells, including human smell, while the other reacts only to humans. According to the researchers, having two of them could help mosquitoes focus on their targets.
They were thus able to determine the glomeruli that mosquitoes use to detect humans, and identify what they detect – decanal and undecanal, two chemicals enriched in human scent and that mosquitoes use to recognize it.
With these results, the researchers have patented a decanal-containing mixture that they hope could lead to baits that lure mosquitoes to deadly traps, or repellents that interrupt the signal in their brains and turn us into mosquitoes. choice prey.