A scary discovery in genetics

Psychological trauma or childhood stress can forever alter genes in the brain, Canadian researchers claim.

Photo: pro.corbis.com.

Finding people who commit suicide whose childhood has been neglected or abused is difficult, yet Moshe Szyf and his colleagues must also have the brains of those who commit suicide.

In 13 approved cases, Quebec staff Suicide Brain Bank is allowed to take out the hippocampus part of the skull - the brain region plays an important role in learning and remembering. . They shredded the brain just a few centimeters long, put it in a transparent plastic container, frozen to -80 ° C and brought it to the lab of Professor Szyf at McGill University in Montreal, Canada.

Professor Szyf developed the idea of ​​studying the brains of suicidal people while experimenting on mice. He wondered why the pups that were not cared for by their mother's mouse grew up to be timid creatures, always fleeing into the darkest corner of the cage. This unusual move, identified by Szyf, is linked to a sudden change in the genome: Gene for receptor processing stress in neural tissue has lost its ability to function.

Stress disturbs normal activity of genes? Almost no one believes that there is such a direct effect. And here comes one more question: Are there similar things in humans? Do parents neglect or abuse their children, forever changing the genes in the baby's brain?

Szyf wants to answer the question thanks to samples from Quebec. His research team isolated DNA genetic material from suicide cells of suicidal people and found in it a trace of childhood abuse that may have left.

And indeed the analysis has brought that: A key gene in the hippocamus cells of the victims no longer works well. Although the gene itself was not damaged, it was switched off, because of a chemical catalyst.

By comparison, researchers examined the brains of people who died of accidents that by the time they left abruptly they lived a happy life. In this gene they are not impaired.

"Experience in childhood marks the brain," Szyf believes. "This mark is left and at some point will cause something like a disease. In the cases we examined it was suicide."

With this conclusion, Szyf went beyond the question of abuse. His conjecture brought the overall interaction of the environment, genes and attitudes to behave in front of a whole new light.

Of course it has long been known that abuse will leave soul wounds. But no one knows what neurological processes cause this.

This frightening discovery draws attention to a fledgling field of epigenetics: The experience of leaving behind chemical traces can be inherited. This suggests the long-term view - assuming that only random mutations of new DNA can create new traits for the next generation - seems to be a doctrine of biology.