Hypothalamic control of male aggression-seeking behavior.

Abstract

In many vertebrate species, certain individuals will seek out opportunities for aggression, even in the absence of threat provoking cues. While several brain areas have been implicated in generating attack in response to social threat, little is known about the neural mechanisms that promote self-initiated or “voluntary” aggression seeking when no threat is present. To explore this directly, we utilize an aggression-seeking task wherein male mice can self-initiate aggression trials to gain brief and repeated access to a weaker male that they attack. In males that exhibit rapid task learning, we find that the ventrolateral part of the ventromedial hypothalamus (VMHvl), an area with a known role in attack, is essential for aggression seeking. Using both single unit electrophysiology and population optical recording, we find that VMHvl neurons become active during aggression seeking and their activity tracks changes in task learning and extinction. Inactivation of the VMHvl reduces aggression-seeking behavior, whereas optogenetic stimulation of the VMHvl accelerates moment-to-moment aggression seeking and intensifies future attack. These data demonstrate that the VMHvl can mediate both acute attack and flexible seeking actions that precede attack.