Our genes determine the traces that stress leaves behind on our brains

August 18, 2014
Our genes determine the traces that stress leaves behind on our brains.
Our genes determine the traces that stress leaves behind on our brains

Our individual genetic make-up determines the effect that stress has on our emotional centres. These are the findings of a group of researchers from the MedUni Vienna. Not every individual reacts in the same way to life events that produce the same degree of stress. Some grow as a result of the crisis, whereas others break down and fall ill, for example with depression. The outcome is determined by a complex interaction between depression gene versions and environmental factors.

The Vienna research group, together with international cooperation partners, have demonstrated that there are interactions between and certain risk gene variants that subsequently change the volume of the forever.

The hippocampus is a switching station in the processing of emotions and acts like a central interface when dealing with stress. It is known to react very sensitively to stress. In situations of stress that are interpreted as a physical danger ('distress'), it shrinks in size, which is a phenomenon observed commonly in patients with depression and one which is responsible for some of their clinical symptoms. By contrast, positive stress ('eustress'), of the kind that can occur in emotionally exciting social situations can actually cause the hippocampus to increase in size.

According to the results of the study, just how stressful impact on the size of the hippocampus depends on more than just . There are genes that determine whether the same life event causes an increase or decrease in the volume of the hippocampus, and which therefore defines whether the stress is good or bad for our brain. The more risk genes an individual has, the more negative an impact the "life events" have on the size of the hippocampus. Where there are no or only a few risk genes, this life event can actually have a positive effect.

Examining life crises

As part of the study, carried out at the University Department of Psychiatry and Psychotherapy (led by Siegfried Kasper), the study team obtained quantitative information from healthy test subjects about stressful life events, such as deaths in the family, divorce, unemployment, financial losses, relocations, serious illnesses or accidents.

A high-resolution anatomical magnetic resonance scan was also carried out (at the High-Field MR Centre of Excellence, Department of MR Physics, led by Ewald Moser). The University Department of Laboratory Medicine (Harald Esterbauer and colleagues) carried out the gene analyses (COMT Val158Met, BDNF Val66Met, 5-HTTLPR). At the University Department of Psychiatry and Psychotherapy, primary author Ulrich Rabl measured the volume of the test subjects' hippocampi using computer-assisted techniques and analysed the results in the context of the genetic and environmental data.

"People with the three gene versions believed to encourage depression had a smaller hippocampus than those with fewer or none of these gene versions, even though they had the same number of stressful life events," says study leader Lukas Pezawas, describing the results. People with only one or even none of the risk genes, on the other hand, had an enlarged hippocampus with similar life events.

The study highlights the importance of gene and environment interaction as a determining factor for the volume of the hippocampus. "These results are important for understanding neurobiological processes in stress-associated illnesses such as depression or . It is ultimately our genes that determine whether stress makes us psychologically unwell or whether it encourages our mental health," explains Pezawas.

The study, published in the highly respected Journal of Neuroscience, was funded by a special research project of the FWF (Austrian Science Fund) (SFB-35, led by Harald Sitte) and presented as a highlight at the international conference on "Organization for Human Brain Mapping."

Explore further: Japan quake shows how stress alters the brain

More information: "Additive Gene–Environment Effects on Hippocampal Structure in Healthy Humans" – Ulrich Rabl, Bernhard M. Meyer, Kersten Diers, Lucie Bartova, Andreas Berger, Dominik Mandorfer, Ana Popovic,Christian Scharinger, Julia Huemer, Klaudius Kalcher, Gerald Pail, Helmuth Haslacher, Thomas Perkmann, Christian Windischberger, Burkhard Brocke, Harald H. Sitte, Daniela D. Pollak, Jean-Claude Dreher, Siegfried Kasper, Nicole Praschak-Rieder, Ewald Moser, Harald Esterbauer, and Lukas Pezawas. The Journal of Neuroscience. 2014 Jul 23;34(30):9917-26. DOI: 10.1523/JNEUROSCI.3113-13.2014.

Related Stories

Japan quake shows how stress alters the brain

April 29, 2014
(HealthDay)—A small study of people who experienced the devastating 2011 earthquake in Japan shows that although traumatic events can shrink parts of the brain, some of those regions can rebound once a person's self-esteem ...

Early life stress can leave lasting impacts on the brain

June 27, 2014
For children, stress can go a long way. A little bit provides a platform for learning, adapting and coping. But a lot of it—chronic, toxic stress like poverty, neglect and physical abuse—can have lasting negative impacts.

Study finds traumatic life events biggest cause of anxiety and depression

October 16, 2013
A study by psychologists at the University of Liverpool has found that traumatic life events are the biggest cause of anxiety and depression, but how a person thinks about these events determines the level of stress they ...

New research might help people suffering from post-traumatic stress disorder

August 1, 2011
The discovery of a mechanism in the brain explains for the first time why people make particularly strong, long-lasting memories of stressful events in their lives and could help sufferers of post-traumatic stress disorder.

Small hippocampus associated with depression in the elderly: Risk factor or shrinkage?

July 19, 2011
Imaging studies have repeatedly found that people with depression have smaller hippocampal volumes than healthy individuals. The hippocampus is a brain region involved in learning and memory, spatial navigation, and the evaluation ...

Recommended for you

The neural codes for body movements

July 21, 2017
A small patch of neurons in the brain can encode the movements of many body parts, according to researchers in the laboratory of Caltech's Richard Andersen, James G. Boswell Professor of Neuroscience, Tianqiao and Chrissy ...

Faulty support cells disrupt communication in brains of people with schizophrenia

July 20, 2017
New research has identified the culprit behind the wiring problems in the brains of people with schizophrenia. When researchers transplanted human brain cells generated from individuals diagnosed with childhood-onset schizophrenia ...

Scientists reveal how patterns of brain activity direct specific body movements

July 20, 2017
New research by Columbia scientists offers fresh insight into how the brain tells the body to move, from simple behaviors like walking, to trained movements that may take years to master. The discovery in mice advances knowledge ...

Scientists discover combined sensory map for heat, humidity in fly brain

July 20, 2017
Northwestern University neuroscientists now can visualize how fruit flies sense and process humidity and temperature together through a "sensory map" within their brains, according to new research.

Team traces masculinization in mice to estrogen receptor in inhibitory neurons

July 20, 2017
Researchers at Cold Spring Harbor Laboratory (CSHL) have opened a black box in the brain whose contents explain one of the remarkable yet mysterious facts of life.

Speech language therapy delivered through the Internet leads to similar improvements as in-person treatment

July 20, 2017
Telerehabilitation helps healthcare professionals reach more patients in need, but some worry it doesn't offer the same quality of care as in-person treatment. This isn't the case, according to recent research by Baycrest.


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.