The Smell of Danger: Rodent Olfaction and the Chemistry of Instinct
The mechanics of instinctive behavior are mysterious. Even something as simple as the question of how a mouse can use its powerful sense of smell to detect and evade predators, including species it has never met before, has been almost totally unknown at the molecular level until now.
David Ferrero and Stephen Liberles, neuroscientists at Harvard Medical School, have discovered a single compound found in high concentrations in the urine of carnivores that triggers an instinctual avoidance response in mice and rats. This is the first time that scientists have identified a chemical tag that would let rodents sense carnivores in general from a safe distance. Mice have about 1200 kinds of odor receptors. In comparison, humans —who rely more on vision than smell— have about 350 odor receptors.
According to Liberles, "In humans, the parts of the brain that deal with likes and dislikes go awry in many diseases, like drug addiction, and predator odor responses have been used to model stress and anxiety disorders. Going from chemicals to receptors to neural circuits to behaviors is a Holy Grail of neuroscience."
SOURCE = PSYORG.COM
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