Scientists look to disrupt brain chemistry of violence

TheNews
Apr. 23, 2007

WASHINGTON - Strides in understanding human brain chemistry and genetics are giving scientists hope they may be able to defuse violent behaviour to avoid tragedies like last week’s university massacre in Virginia, neurologists say.

The shooter, a 23-year-old South Korean who had lived in the United States since he was a child, killed 32 people before committing suicide, in the deadliest school shooting in US history. “There is no doubt in my mind that if we could have examined his brain (the killer at Virginia Tech) we would have found anomalies, and we would have been able to suggest for him to get therapies,” said Dr Allan Siegel, a neurologist and researcher at the University of Medicine of New Jersey (UMDNJ).

“We might have been able to avoid this ... if he had been treated properly in the hospital setting,” Siegel told AFP.

Clinical research as well as animal testing, particularly on cats, over some 40 years has shown that there are specific zones in the brain linked to aggression and violence, he said.

The front region of the brain, or the prefrontal cortex, including the limbic system, appears to play an important role in violent behaviour, according to the neurologist.

The killer Charles Whitman, who gunned down 16 people at the University of Texas in the 1960s, was found to have a tumour in the temporal lobe in the region of the limbic system, he said.

The link between the prefrontal cortex and violence was first revealed in 1848 in the case of a railroad worker, Phineas Gage, whose skull was impaled by an iron rod in an explosion — damaging the front part of his brain.

Gage survived the accident but his behaviour radically changed, with his formerly respectful, sensitive manner replaced by an impulsive and aggressive personality. Medical cases since have linked violent tendencies to damage to the front part of the brain, Siegel said.

A recent study shows children who suffer injury to the prefrontal cortex before age seven developed abnormal behaviour, characterised by an inability to control their frustration, anger and aggression, according to an article in the journal Neuroscience.

Neurologists believe the frontal region regulates and controls aggression and violent impulses. A brain imaging study of 41 murderers found evidence that in most cases the prefrontal cortex as well as some deeper brain areas, including the amygdala, functioned abnormally, researchers wrote in the Neuroscience article.

In the case of the Virginia Tech gunman, a medical investigation would also have to examine if he suffered a deficiency in his serotonin system, said Klaus Miczek, a neuroscientist at Tufts University.

Serotonin is a neurotransmitter in the central nervous system and low levels have been associated with several disorders.

“Brain sertonin is a transmitter that has been investigated more than any other transmitter when it comes to violent, aggressive activity,” Miczek said.

A number of drugs have proved effective in controlling violent impulses by compensating for serotonin deficiencies, said Siegel, citing prozac and lithium used also to treat schizophrenia.