To his saliva?…, you may wonder, that’s right. A new study reveals that cats, rats and other predators produce a chemical in their saliva with which they terrorize mice.
The American researchers discovered that when mice detect this compound – which is also found in the urine of rats – react with fear. In fact, this compound is called major urinary protein, or Mup. It acts on the cells of a special sensory organ in mice, called the Jacobson’s or vomeronasal organ.
As the scientists explain in Cell magazine, Mups cause a terrifying reaction in the mouse. The vomeronasal organ contains neurons that detect chemical signals and is connected to areas of the brain involved with memory, emotion, and hormone release. It is already known that in many mammals the organ can detect pheromones, the chemical messengers that communicate information between individuals of the same species. These pheromones can have a direct effect on the behavior of animals.
But in the new study, the scientists found that in mice the neurons of the vomeronasal organ are also stimulated by the chemical signals emitted by their predators.
In mice, these proteins cause the animal to exhibit fear signals such as stay “freeze” or stay crouched close to the ground while carefully sniffing and investigating the surroundings.
And I thought I knew everything, many things still to be discovered on our Curious Planet.
Source: BBC World