IVAN DE ARAUJONeural circuits in the amygdala are responsible for predatory behavior in mice, according to a study published January 12 in Cell. Using optogenetics, a technique that uses light to turn neural circuits on and off, a group of researchers led by neuroscientist Ivan de Araujo of Yale University was able to turn docile mice into ruthless hunters.
Earlier research revealed that the amygdala, an almond-shaped brain structure most commonly linked to fear, was active when rats were hunting and feeding. To see whether this brain region was actually controlling predatory behavior, Araujo and colleagues decided to use optogenetics to selectively activate specific neurons in mice, with light.
When the researchers activated the amygdala, docile mice attacked everything from bottle caps to live insects. Even when there was no prey in sight, the mice displayed feeding behavior—moving their jaws and lifted their paws as if holding a piece of food. Once the light was switched off, the animals went back to peacefully strolling around their cages.
“It’s not just physiological, it’s hunting, biting, releasing and eating. Those are motor sequences that require a lot of information, so it’s remarkable you can get this behavior with that sort of gross manipulation,” Kay Tye, a neuroscientist at the Massachusetts Institute of Technology in Cambridge who was not involved in the study, told Nature.
This study adds to the growing list of functions of the amygdala. “The central amygdala has been linked to escape and flight — this is completely different from that,” Tye told Nature.