Severe stress suffered at an early age can cause long-lasting changes to gene expression patterns in the mouse brain, reports a study published online in this week's Nature Neuroscience.
Previous studies have shown that children growing up under stressful or traumatic circumstances carry an elevated risk of developing depression later in life. To elucidate the underlying neurobiological causes, Dietmar Spengler and colleagues studied mouse pups that were repeatedly separated from their mothers during the first ten days of life. This stressful separation caused a specific loss of suppression mechanisms at the gene encoding the stress-related hormone AVP, which in turn led to elevated levels of this hormone.
One year after the stressful phase in the pups' lives, Spengler and colleagues still found the aberrant gene modification, AVP elevation, and ensuing physiological over-reaction towards other stressful situations. The researchers conclude that the long-lasting behavioral, and sometimes psychiatric, consequences of early-life stress may be due in part to persistent changes of gene regulation in the brain.