For the first time, researchers have determined how a human olfactory receptor captures an airborne scent molecule, the pivotal chemical event that triggers our sense of smell.

Whether it evokes roses or vanilla, cigarettes or gasoline, every scent starts with free-floating odor molecules that latch onto receptors in the nose. Multitudes of such unions produce the perception of the smells we love, loathe or tolerate. Researchers therefore want to know in granular detail how smell sensors detect and respond to odor molecules. Yet human smell receptors have resisted attempts to visualize how they work in detail — until now.

— Read more in How a Human Smell Receptor Works Is Finally Revealed at Quanta Magazine.

Smell involves about 400 unique receptors. Each of the hundreds of thousands of scents we can detect is made of a mixture of different odor molecules. Each type of molecule may be detected by an array of receptors, creating a puzzle for the brain to solve each time the nose catches a whiff of something new.

“It’s like hitting keys on a piano to produce a chord,” said Hiroaki Matsunami, PhD, professor of molecular genetics and microbiology at Duke University...

— Read more in Study reveals how odor molecule activates human odorant receptor at The Print.

While odors themselves were regarded with distrust, it seems like every famous man in history who ever felt moved to write about our sense of smell had some derogatory point to make (there’s a notable shortage of opinions from the women of history). Most fall into one of two camps: those who regarded smell as relatively unimportant, and those who associated it with depravity. Plato considered that smell was linked to “base urges,” while others described it as degenerate and animalistic. Aristotle wrote that “man smells poorly” and Darwin asserted that “the sense of smell is of extremely slight service.”

— Read more in How Smell—the Most Underrated Sense—Was Overpowered By Our Other Senses at LitHub.

Breaking a longstanding impasse in our understanding of olfaction, scientists at UC San Francisco (UCSF) have created the first molecular-level, 3D picture of how an odor molecule activates a human odorant receptor, a crucial step in deciphering the sense of smell.

— Read more in First molecular images of olfaction open door to creating novel smells at Phys.org.