Genes And Life Stress Interact In The Brain August 23, 2009
People who carry a particular genetic variation are more likely to respond to stress by becoming depressed and by ruminating on the event, according to a study by researchers at Yale School of Medicine, Stony Brook University, and the University of Wurzburg, Germany.
Prior research identified a genetic variation within the serotonin transporter gene as a potential culprit for these individual differences, but the basis for this effect was unknown.
This study, published online in the Proceedings of the National Academy of Sciences, is the first evidence for the neural basis for this gene-environment interaction. Turhan Canli of Stony Brook led the team and R. Todd Constable, professor of diagnostic radiologyand neurosurgery at Yale, was a co-author.
The research team used a combination of magnetic resonance imaging, genetic analysis, and self-reported life stress and rumination to investigate the interaction of genes and stress in healthy subjects. The subjects looked alternately at images of happy, neutral, fearful and sad faces.
They found that individuals who carried one or two copies of the short variant of the serotonin transporter gene had increased levels of brain activity in the amygdala and hippocampus, two regions previously associated with depression and stress.
The researchers also reported that carriers of the short variant experienced higher levels of rumination in response to stress.
“These individual differences may render short variant carriers more vulnerable to depression and may have a protective effect in non-carriers,” Constable said.
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