MSNBC.com, March 16, 2011
"Bullying and other types of chronic social stress affect gene activity in the brain, suggests a new study in mice. The changes may lead to persistent social anxiety.
'Just as alcohol affects your liver, stress affects your brain,' said lead researcher Yoav Litvin of Rockefeller University in New York. The anxiety that can result from being teased and otherwise treated poorly is organically based, Litvin said, meaning it arises from physical changes in the brain.
In the study, adult male mice were basically set up to be humiliated. (Mice are thought to have roughly similar responses to stress as humans.)
The researchers placed a small, young test mouse in the cage of a bigger, older mouse. Due to the instinctive territoriality of mice, a fight always ensued, which the newcomer always lost. The fights were rarely vicious, but the younger mouse quickly understood he was lower down on the social totem pole. (The experiment caused more psychological stress then physical harm.)
The same mouse was subjected to 10 different cages on 10 different days — and was knocked around by the cage's resident bully each time. Then the researchers examined each mouse's brain, looking at areas associated with emotion and social behavior, such as the amygdala and the lateral septum, which is located near the middle of the forebrain." Read More