Aggressive behaviour in mice might be due to changes in brain cells of a particular region called the lateral septum. The paper published in the journal Current Biology might provide further insight into aggressiveness in other animals.
Why do some people give in to violent outbursts that seem to come from nowhere? What causes this behaviour? A new study provides a potential explanation. The researchers say their findings could provide further insight into aggression in animals.
The causes behind sudden violent behaviour have been linked with changes in a brain structure called the lateral septum, says a team of researchers led by Dayu Lin from New York University.
The team was analysing the brain of mice when they made the discovery. They also found that they could activate certain brain cells in that area to switch the aggressive behaviour on and off. They did so by inserting a probe into the mice’s brains surgically to excite the brain cells using light. This would modify their activity and start and stop the violent outbursts called septal rage such that the mice were stimulated to attack fellow mice.
This was brought about because the lateral septum is linked with the hippocampus (which is involved in learning and processes entailing emotions) and with the hypothalamus (which is linked with the production of hormone and aggression). The two latter regions are said to send signals to the lateral septum. When the cells in the lateral septum were activated, activity in the ventrolateral region of the ventromedial hypothalamus increased. When this happened, the activity of another set of brain cells in the same region decreased. The cells that were most active in the ventrolateral region during aggression were those most suppressed with septal stimulation and vice-versa.
Lin concludes that lateral septum in mice has a “gatekeeping role”; it both applies the brakes and “lifts the foot off the accelerator” when it comes to violent behaviour.
While septal rage has not been found in humans, the results of the study might assist in the research in aggression among us.