Ask a scientist: How do we smell?

Scientist Richard Axel answers the question: How do we smell?


For most animals, odors are the central sensory modality used to communicate with the world.

How is it that we can recognize a vast repertoire of odors in the world?

Through molecular chicanery, we were able to show that we do this by virtue of having in cells neurons in our nose dedicated to the recognition of odors, and these neurons as a population make in most species very large numbers of what are called 'receptors,' each capable of binding to different combinations of odors.

And it's not until you get to evolutionarily highly evolved creatures -- primates, monkeys, man -- that smell begins to take second place among the senses to vision.