Animal models of excessive aggression: implications for human aggression and violence

•Violence as the pathology of aggressive behavior can validly be modeled in animals.•Like in humans, only a minor fraction of individuals exhibit excessive aggression.•Optogenetics revealed attack-promoting neurons in the ventrolateral hypothalamus.•Dysfunction in serotonin signaling determines the vicious cycle to violence.

Escalated interpersonal aggression and violence are common symptoms of multiple psychiatric disorders and represent a significant global health issue. Current therapeutic strategies are limited due to a lack of understanding about the neural and molecular mechanisms underlying the 'vicious' shift of normal adaptive aggression into violence, and the environmental triggers that cause it. Development of novel animal models that validly capture the salient features of human violent actions combined with newly emerging technologies for mapping, measuring, and manipulating neuronal activity in the brain significantly advance our understanding of the etiology, neuromolecular mechanisms, and potential therapeutic interventions of excessive aggressive behaviors in humans.