Tears for Fears :Juvenile mice secrete a protective pheromone in their tears, blocking adult mating

The information we obtain through our senses helps to guide our behavior, and it's the same in mice as it is for humans. Mice rely heavily on #scent, and it often only requires action at several synapses before a scent triggers instinctual behavior. It's something young mice rely on to protect themselves from the mating overtures of adult male mice. Researchers at #Harvard Medical School have identified a new#pheromone known as ESP22 that is found in the tears of young mice. In work published in Nature, the researchers showed that the gene that codes for ESP22 is only expressed in juvenile mice, and that it specifically activates sensory neurons in the #vomeronasal organ (VNO). ESP22 also appears to activate neurons in the #limbic system, which helps control instinctual behavior. Adult male mice lacking the VNO displayed sexual behavior towards juveniles, as did normal adult male mice towards juveniles that couldn't make ESP22. Humans don't make a version of ESP22, nor do we rely on scent, so scientists have no reason to think that we use such a system. However, the researchers hope that insights from studying ESP22 in mice helps us understand what triggers instinctual behavior. 

Read more: http://hvrd.me/GzGa9q
Journal article: A juvenile mouse pheromone inhibits sexual behaviour through the vomeronasal system. Nature, 2013.