Scientists at the institute monitored the effects of early-life stress to mice and found evidence that they generated changes to gene regulation that caused the animals to produce more stress hormones and struggle to handle difficult situations, according to findings published in the latest edition of the scientific journal Nature Neuroscience.
“The new findings document how environmental factors affect our genes and open a better understanding for the development of stress-related illnesses such as depression,” the institute explained in a statement.
Medical experts have known for some time that childhood trauma increases the risk for depression and anxiety, but the molecular mechanism behind this tendency was unknown until now, the institute said.
“Our study documents how environmental influences are reflected at the molecular level of our genomes via epigenetic mechanisms,” head of the institute in Munich Florian Holsboer said. “The understanding of this epigenetic coding will be the key to new treatment strategies.”
The mice were separated from their mothers soon after birth, and their traumatised brains produced a lifelong excess of the protein molecule vasopressin, a key factor in regulating stress hormones, emotions and social behaviour.
In the search for what produced the excess vasopressin, the researchers found that the mice were missing a genetic methyl group attachment that stops overproduction of the molecule in healthy animals. Their genes essentially “learned” from their environment, the study found.