The portion of the mouse brain called the lateral septum and implicated in the control of rage is seen highlighted in green. Photo by Current Biology and Cell Press

NEW YORK, Feb. 11 (UPI) -- Scientists have located the origins of "rage" in the brains of laboratory mice.

Researchers at the New York University School of Medicine and NYU Langone Medical Center identified changes in areas of the brain linked with anxiety and fear during violent, unprovoked outbursts.


Scientists have previously shown that mice with damage to their lateral septum, a midbrain wall structure, were more prone to violent and sudden behavior -- usually attacks on other mice. The damage can trigger a domino effect of activity in other brain regions.

Researchers have dubbed this cascade or neural activity "septal rage."

The lateral septum is linked by brain circuitry to both the hippocampus and hypothalamus. The hippocampus governs emotion and learning, while the hypothalamus controls aggression and hormone production.

With light from a surgically inserted probe, researchers stimulated cells in the lateral septum to control cells in the hypothalamus, making one set cells more active and suppressing another set. During mice attacks, the cells found to be most active were those suppressed during septal stimulation.

"Our latest findings show how the lateral septum in mice plays a gatekeeping role, simultaneously 'pushing down the brake' and 'lifting the foot off the accelerator' of violent behavior," lead researcher Dayu Lin, an assistant professor at NYU Langone's Druckenmiller Neuroscience Institute, said in a news release.

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Though no direct parallel to septal rage has been identified in the human brain, researchers believe the discovery will aid researchers' exploration and understanding of the origins of violent behavior in humans.

The findings, published in the journal Current Biology, suggest a healthy lateral septum is key in suppressing violent impulses.

"Our research provides what we believe is the first evidence that the lateral septum directly 'turns the volume up or down' in aggression in male mice, and it establishes the first ties between this region and the other key brain regions involved in violent behavior," Lin said.