Under normal conditions, female mosquitoes rely on the cocktail of smells that humans and other animals emit to detect the blood they need to nourish their eggs. They pick up scents through olfactory neurons located primarily on their antennae, which detect and transmit scent information to the brain. But now, the result is pretty surprising.
“At first glance, mosquito olfaction makes no sense. The way the mosquito organizes its sensation of smell is completely unexpected,” says Leslie Vosshall, the Robin Chemers Neustein Professor at The Rockefeller University and Chief Scientific Officer of the Howard Hughes Medical Institute.
“But for the mosquito, it makes perfect sense. Every neuron that interprets smell is redundant in such a way that the olfactory system is essentially unbreakable. This may explain why we haven’t found a way to break mosquitoes’ attraction to humans.”
There are a lot of overlaps
Scientists often think of the brain processing smells with a 1:1:1 (one-neuron-one-receptor-one-glomerulus model) system for insects and mammals. Each olfactory neuron expresses one odor receptor that communicates with one cluster of nerve endings, known as a glomerulus.
However, it is observed that some species have almost the same number of olfactory receptors as glomeruli. For instance, honeybees have 180:160, or tobacco hornworms have 60:70.