According to researchers at Washington University School of Medicine in St. Louis, a group of steroids found in female mouse urine goes straight to the male mouse’s head and may cause it to sing.

These particular steroids, known as glucocorticoids (GCC), are associated with energy metabolism, stress and immune function. It has not been actually established if this particular steroid causes the male mouse to sing.

Pheromones, found in urine, sweat, and other bodily fluids have long been recognized to influence the behavior of others. Most mammals use this for social purposes, like establishing territory or dominance, or in courtship and mating.

In the study, female mice were stressed, leading to a threefold increase in the levels of GCCs in their urine. This directly linked the female mouse’s health and the GCC pheromones.

The GCC pheromones identified were comprised of sulfur and oxygen atoms. When an enzyme was used to alter some of their composition, the GCCs lost their ability to activate nerves.

Researchers believed that GCC pheromones account to at least 75% of the signals detected in female urine by the male accessory olfactory system. A higher degree of activation means a higher potential for advancing the study of pheromones.

From Eureka Alert:

St. Louis, June 16, 2008 — A group of steroids found in female mouse urine goes straight to the male mouse’s head, according to researchers at Washington University School of Medicine in St. Louis. They found the compounds activate nerve cells in the male mouse’s nose with unprecedented effectiveness.

“These particular steroids, known as glucocorticoids (GCCs), are involved in energy metabolism, stress and immune function,” says senior author Timothy E. Holy, Ph.D., assistant professor of neurobiology and anatomy. “They control many important aspects of the mouse’s physiology and theoretically could give any mouse that sniffs them a detailed insider’s view of the health of the animal they came from.”