by Lin Edwards in PhysOrg.com:
A new study of mice suggests that stress and trauma in early life can have an impact on the genes and result in behavioral problems later in life.
Scientists from the Max Planck Institute of Psychiatry in Munich, Germany, looked at the long-term effects of stress mice suffered soon after their birth. The stress was produced by separating the mouse pups from their mothers for three hours a day for the first ten days of their lives. The separation did not affect their nutrition but would have made them feel abandoned. The pups were then followed through their lives.
The researchers found the stress caused the baby mice to produce hormones that altered their genes and affected their later behavior, making them less able to cope with stress later in life. The mice exposed to the stresses also had poorer memories than the control group.
The leader of the team, Dr Christopher Murgatroyd, told the BBC that the research for the first time showed in molecular detail how stress in early life could program behavior later on. The stress had caused the animals to produce high levels of stress hormones, and this in turn had led to epigenetic changes, meaning that the experience had changed the DNA of a gene coding for the stress hormone vasopressin, which is important in controlling mood and cognitive behaviors. The result of the genetic changes meant the brain developed more receptors for vasopressin.