Early life stress has effects at the molecular level

Nov 12, 2009 by Lin Edwards weblog
Mouse pups that are just a day old. Image: Muhammad Mahdi Karim, via Wikipedia

(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 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 , and this in turn had led to epigenetic changes, meaning that the experience had changed the DNA of a 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.

In humans vasopressin is known to be involved in such as parent/child bonding. In rodents, higher levels of vasopressin have also been shown to increase aggressive behavior.

The change in the vasopressin gene resulted in the mice being "programmed" to produce high levels of the stress hormone in their adult lives. The study was also able to prove that vasopressin was involved in the behavioral problems and poorer memories of the stressed mice, because when the adults were given a drug to block the vasopressin effects, their behavior became more normal.

The study in mice may have implications in human studies of how the effects of trauma in childhood can lead to problems in later life, such as depression. Until the present study, scientists have not understood the mechanism by which early stress could have far-reaching effects. An understanding of the molecular basis for the phenomenon could help scientists develop therapies for mental disturbances arising from early stress or .

The paper was published on November 8 in the online version of the journal.

More information: Dynamic DNA methylation programs persistent adverse effects of early-life , Nature Neuroscience, Published online: 8 November 2009; doi:10.1038/nn.2436

© 2009 PhysOrg.com

Explore further: Seeing is believing: How brains make sense of the visual world

Related Stories

Enzyme regulates brain pathology induced by cocaine, stress

Nov 08, 2007

Researchers have uncovered a key genetic switch that chronic cocaine or stress influences to cause the brain to descend into a pathological state. In studies with mice they showed how chronic cocaine changes gene activity ...

Cocaine changes gene activity in mice

Dec 04, 2007

A team of U.S. researchers has found chronic cocaine administration in mice changes the activity of their genes, enhancing the rewarding effect of cocaine.

Studies relate life experiences to brain structure

Mar 11, 2005

Recent studies from the lab of neuroscientist Elizabeth Gould are helping to show how major experiences -- such as early-life traumas -- can have a long-term effect on the structure of the brain. In one study published las ...

A brain chemical that battles despair

Jul 18, 2007

Researchers have identified a gene-regulating protein in the brains of mice that triggers the animals' ability to cope with the "behavioral despair" caused by inescapable stress. They said their studies have yielded an animal ...

Recommended for you

Brain study sheds light on how new memories are formed

4 hours ago

In the first study of its kind, UCLA and United Kingdom researchers found that neurons in a specific brain region play a key role in rapidly forming memories about every day events, a finding that may result ...

Human brain may contain a map for social navigation

4 hours ago

The brain region that helps people tell whether an object is near or far may also guide how emotionally close they feel to others and how they rank them socially, according to a study conducted at the Icahn ...

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.