Many animals behave according to the surrounding information obtained from the sense of smell.For example, it escapes when it senses an animal that is a natural enemy, and tries to approach it when it senses the opposite sex of the same species.
It is known that in rodents, a signal such as a pheromone is received by an olfactory system called the vomeronasal nervous system, which is separate from the main olfactory system, and behavior is exhibited in response to the signal.For example, the urinary protein of male mice promotes sexual behavior in females of the same species, and the urinary protein of rat, which is a predator of mice, causes repellent behavior in mice.
In recent years, the presence of pheromones that are accepted by the vomeronasal nervous system in tears has been revealed, but it was not known whether they also act on heterologous animals.Therefore, research groups such as Azabu University and the University of Tokyo have focused on rats and mice that have a predator-prey relationship in nature, and whether or not tear fluid causes a change in behavior to different animals via the sense of smell. investigated.
First, when we investigated whether rat tears contained a substance accepted by the vomeronasal organs of mice, we found a protein called Cystatin-related protein 1 (ratCRP1) that is expressed only in males and whose function has not been elucidated. Was done.When female rats receive ratCRP1, they show behaviors that promote sexual behavior, while mice that are prey to rats not only avoid the places where ratCRP1 is sensed by reception, but also reduce body temperature and heart rate. He entered a "shrug" position, such as a decrease in the amount of activity that accompanies it.
From the above results, it was clarified that ratCRP1 is used as a sexual signal between male and female rats, and at the same time, it acts as a natural enemy signal indicating the existence of heterologous animals for mice.The findings will deepen our understanding of how rodents are subject to behavioral control by olfactory-mediated chemosensory signals.
Paper information:[Current Biology] Identification of an intra- and inter-specific tear protein signal in rodents
