It takes two to court

Pheromones are chemical signals that stimulate social responses in others of the same species.

These chemical signals are detected by pheromone receptors located in nasal tissue. Pheromones can let an animal know when a suitable mate is near and activate the release of hormones that encourage the animal to mate.

Researchers at the Stowers Institute led by Investigator C. Ron Yu, PhD, have identified the functions of two classes of pheromone receptors. They found one class of receptors helps a male mouse detect pheromones that indicate when a female is present. The other class of receptors lets him know if the female mouse is ovulating and ready to mate. Both sets of pheromones are critical to trigger mating. Stowers’ researchers believe mice developed this system through evolution to maximize the chance of their reproductive success.

“Interestingly, the pheromone that tells other mice that ‘I am female,’ or the one that tells others, ‘I am ovulating,’ do not do much on their own,” says Yu. “But when the two are presented together, the male mice showed great interest in courting and mating with the female.”

Yu and his colleagues plan to build on their research to identify other pheromones and receptors, and map out the neural circuitry that transmits information from the pheromone receptors to the brain. Their findings open the door for the discovery of the neural pathways that activate inborn behavior in mammals, including humans.

“These next steps will help us understand how mammalian brains integrate multiple pieces of information to make critical decisions in their lives,” says Sachiko Haga-Yamanaka, PhD, the study’s lead author.

The study was published in the July 29, 2014 issue of the online journal eLife.