Study Shows How Childhood Trauma Influences Behaviour

Lisa Franchi December 03, 2014

It is a known fact that traumatic and stressful events during childhood can increase the risk of developing psychiatric disorders. But to a certain extent, they can also help better individuals deal with difficult situations later in life. Researchers have studied this phenomenon in mice to learn how these effects could be transmitted to the next generation.

People exposed to a traumatic experience early in life are more likely to be affected by illnesses such as borderline personality disorder or depression. However such experience can also have positive effects in certain circumstances. Thus, moderate stress in childhood may help a person develop strategies to better cope with stress in adulthood.

Further, it has long been recognised by psychologists and psychiatrists that the negative effects of trauma experienced by parents can be seen in their children, but the molecular mechanisms underlying such transmission are only beginning to be identified. A research team led by Isabelle Mansuy, Professor of Neuroepigenetics at the University of Zurich and ETH Zurich, has for the first time tested in mice the degree to which the beneficial effects of stress can be passed to following generations.

To determine how this behaviour is expressed and transmitted to the next generation, the researchers examined the activity of a gene, a mineralocorticoid receptor gene previously implicated in flexible behaviour. Mansuy’s team discovered that ’epigenetic’ marks, which determine how much a gene is expressed, were altered on this gene, both in the brain and sperm of the stressed mice when adult.

"Our results show that environmental factors change behaviour and that these changes can be passed on to the next generation," explains Mansuy. This finding - that not only a parent’s susceptibility to psychological disorders can be passed on to its offspring, but also its improved goal-oriented behaviour in difficult situations - might prove to be of value to the clinic.

"We are not in any way suggesting that early-childhood trauma is somehow positive," says Mansuy. But she adds that her study on mice demonstrates how extreme stress can positively or negatively affect the brain and behaviour across generations.

Early life stress in fathers improves behavioural flexibility in their offspring