Mosquito repellent amine provides "invisible cloak" for human body

Researchers have been trying to find out how mosquito repellents affect mosquitoes, but the neural response of Anopheles to mosquito repellents and other repellents is largely unknown, because it is an arduous task to directly study the smell sensitive neurons of mosquitoes Recently, researchers from Johns Hopkins University in the United States reported that applying a genetic engineering technology to the Anopheles mosquito, which spreads malaria, they can see the internal structure of the insect's nose "With the new breed of Anopheles, we can finally ask how mosquito olfactory neurons respond to the odor of repellents." Christopher Potter, an associate professor of Neuroscience at the school, said: "we were surprised by the results from Anopheles We found that Anopheles' olfactory neurons did not respond directly to DEET or other synthetic repellents Instead, these repellents prevented mosquitoes from detecting the odor of human skin In other words, these repellents mask or hide the smell of our skin " When the researchers ejected a mosquito detectable odor, the tentacles with fluorescent particles created by the team lit the neurons, which were recorded by the camera, indicating that the mosquito's nose detected a signal Using the device, researchers found that different odors, including chemical repellents, natural repellents, and chemicals found in human odors, have different effects on mosquito neurons When the researchers sprayed the scent of DEET alone on the antennae of mosquitoes, the fluorescent particles in mosquito neurons did not light up, indicating that mosquitoes could not directly smell the chemical When exposed to the chemicals that make up human odors, neurons light up like Christmas trees It is worth noting that when human odor is mixed with DEET to simulate the effect of insect repellent on the skin, the response of mosquito neurons to the mixture is neutralized, only 15% of the response to human odor To find out why this happens, the researchers measured the number of odorant molecules in the air that reach the antennae of mosquitoes to find out how many odors mosquitoes need to respond They found that when combined with DEET, the number of human odorant molecules in the air decreased by 20% The related research report is published in the current biology.