Wednesday, January 16, 2008

Dopamine and Fight Club

New research from Vanderbilt University shows for the first time that the brain processes aggression as a reward – much like sex, food and drugs – offering insights into our propensity to fight and our fascination with violent sports like boxing and football.

The research will be published online the week of Jan. 14 by the journal Psychopharmacology.

“Aggression occurs among virtually all vertebrates and is necessary to get and keep important resources such as mates, territory and food,” Craig Kennedy, professor of special education and pediatrics, said. “We have found that the ‘reward pathway’ in the brain becomes engaged in response to an aggressive event and that dopamine is involved.”

“It is well known that dopamine is produced in response to rewarding stimuli such as food, sex and drugs of abuse,” Maria Couppis, who conducted the study as her doctoral thesis at Vanderbilt, said.

“What we have now found is that it also serves as positive reinforcement for aggression.” The Vanderbilt experiments are the first to demonstrate a link between behavior and the activity of dopamine receptors in response to an aggressive event.

“We learned from these experiments that an individual will intentionally seek out an aggressive encounter solely because they experience a rewarding sensation from it,” Kennedy said. “This shows for the first time that aggression, on its own, is motivating, and that the well-known positive reinforcer dopamine plays a critical role.”