Mice turn into killers when brain circuit is triggered by laser

Researchers have identified the brain region that controls hunting, and have found a way to switch it on and off. Ivan de Araujo at Yale University and his team have discovered that two sets of neurons in the mouse brain underpin the instinct to kill. One coordinates the pursuit of prey, while the other controls the neck and jaw muscles used for biting. Both are in the amygdala – the part of the brain involved in motivation, emotion and fear. By modifying these neurons so they could be activated by laser light, a technique called optogenetics, the team were able to switch these circuits on whenever they wanted.