Researchers get a better understanding of how mice smell a rat, or a cat
The smell of a protein found in urine leaves mice quaking with fear when they smell it coming from cats and rats, scientists report in the May 14 Cell. Yet when mice smell the same protein coming from other mice, the odor prompts mouse-on-mouse aggression.
What signals the mice to flee in one instance and fight in the other isn’t clear, but the find suggests that the animals have adapted an existing sensory communication system to interpret the scent of danger.
Most animals are hardwired to recognize predators, says study coauthor Lisa Stowers of the Scripps Research Institute in La Jolla, Calif. Lab mice are terrorized by the scent of cat, even though they — and hundreds of generations of their ancestors — have never met one. To explore which molecules might trigger this innate fear response, Stowers and her colleagues exposed lab mice to the scents of several predators, including a cat, a rat and a snake.
They found that each ma