The activation of a particular group of brain cells is all it takes to make mice hunt to kill.

The brain's central amygdala has long been thought to have a role in producing emotions, particularly fear. To activate this brain region, Ivan de Araujo at Yale University in New Haven, Connecticut, and his co-workers engineered mice so that neurons in the central amygdala could be stimulated by light or small molecules. When the team activated the amygdala neurons, the animals' jaw and neck muscles tensed up, and they tried to grab an item, stretching their necks and biting and restraining the object. The mice hunted a variety of items, from crickets to bottle caps.

This and other research suggests that, in addition to emotion, the amygdala regulates a variety of complex behaviours, including feeding, grooming and predation.

Cell 168, 311–324 (2017)