Aggression increases the growth of cells in the brain
Last reviewed: 23.04.2024
All iLive content is medically reviewed or fact checked to ensure as much factual accuracy as possible.
We have strict sourcing guidelines and only link to reputable media sites, academic research institutions and, whenever possible, medically peer reviewed studies. Note that the numbers in parentheses ([1], [2], etc.) are clickable links to these studies.
If you feel that any of our content is inaccurate, out-of-date, or otherwise questionable, please select it and press Ctrl + Enter.
An international group of neurobiologists, which also included specialists from the Moscow Institute of Physics and Technology, found that aggression leads to the growth of new neurons in the brain.
After a series of experiments with rodents, scientists discovered that mouse-aggressors, i.e. Those who started fights with their relatives, became more aggressive after the victory, but in addition, new cells were formed in their hippocampus.
The experiment consisted in the following: two males were placed in a cage, divided into two parts by a grid, which did not prevent rodents from seeing, hearing, smelling each other, but thanks to the grid, the animals could not join the battle. Every day specialists (about the same time) removed the net from the cage and observed the behavior of the males. As a rule, the fight between them came almost immediately. The winner was determined by the scientists themselves, on average after 3 minutes the experts had to block the cage again.
Three days later the rodents were transplanted into other cells, i. E. Changed the "neighbors", while each time the defeated males sat down to other winners. In one group of subjects, the winners were removed from the fighting, and in the other, the clashes continued.
Also, the researchers conducted a test that showed the impact of aggression on animal behavior. Rodents were placed in a cross-shaped labyrinth with one closed corridor, the second part of the labyrinth was open. The behavior of the mice was estimated by which of the two corridors the male chooses, those that chose the dark and closed part of the labyrinth, the scientists described as "avoiding the risk."
Also scientists planted mice in cells with transparent septa and assessed the level of aggression of the experimental subjects. The males, who more often approached the septum and spent more time there, were potentially more aggressive, compared to the "neighbors" in the cage, who prefer to stay away from the septum.
After all the tests and tests, the scientists found out that the rodents who won in several battles were more arrogant, often the first to start a fight.
In addition, males, who were not allowed to fight before the experiments, were more aggressive in behavior, they attacked the enemy more quickly and the fight itself lasted longer. But simultaneously with the aggression, the animals grew a sense of anxiety - the males, who won the fights, preferred to sit out in the dark and closed parts of the labyrinth, i.e. Avoided risk.
Previously, it was suggested that aggressive animals otherwise work the brain and this study confirmed this.
In the brains of the aggressors, the number of neurons in the hippocampus increases, which causes an increase in the level of rodent aggressiveness. Among other things, the animals observed changes in the structure of the tonsils (the site responsible for emotions). In humans, changes in the tonsils are associated with the development of autism and in the experimental animals, several signs of this disease have been identified - an increased sense of anxiety, repetitive movements, a disruption of communication with other rodents.
[