Darcin is a pheromone found in the urine of male mice. It's used to mark territory and signal mating availability, and was named after the character Mr. Darcy who appears in Jane Austin's Pride and Prejudice. In the new issue of Nature, researchers at Columbia University report on how darcin "takes hold in the brains of female mice, giving cells in the brain's emotion center the power to assess the mouse's sexual readiness and help her select a mate."
From the press release:
Pheromones, such as darcin, are processed somewhat differently. They interact with a second, parallel olfactory system, which exists in animals like mice but not in people.
"Unlike people, mice have essentially two functional noses," said Dr. Demir. "The first nose works like ours: processing scents such as the stinky odor particles found in urine. But a second system, called the vomernasal nose, evolved specifically to perceive pheromones like darcin."
For today's study, the research team, which also included Dr. Hurst, Dr. Beynon and co-senior author Adam Kepecs, PhD, of Cold Spring Harbor Laboratory, first exposed female mice to darcin-scented urine and monitored their behavior. Nearly all of the female mice showed an immediate attraction to darcin. Then, after about 50 minutes, some females began leaving their own urinary scent markings. They also started to sing, at ultrasonic frequencies too high for the human ear to hear. Both of these behaviors are an indicator of increased sexual drive.