Early childhood trauma has negative effects in the life of adults who experience it. However, such trauma also has benefits, including making that person more adaptable to stressful situations as they get older.
But is that adaptability capable of being inherited, passed down from parent to child?
New research suggests that the answer is "yes."
Researchers at the University of Zurich and ETH Zurich subjected newborn male mice to stress by taking them away often from their mothers. They analyzed the behavior of these mice when they became adults and compared them to a group of mice not subjected to this stress.
Researchers then gave the adult mice complex tasks. For example, researchers trained mice to poke their nose into a hole 6, 12 or 18 seconds after seeing a light for a drink. The stressed mice did considerably better than those not subjected to stress as newborns. As mice had no access to their fathers during their childhoods, researchers surmised that this ability to perform complicated tasks was not learned, but inherited.
Of course, that meant looking at the genes in the mice. Researchers studied a specific gene involved this kind of behavior. They discovered that the way the gene expressed itself in the brain and sperm was different in the stressed adult mice. Researchers suggest that this altered gene is inherited from one generation to the next in the sperm.
"Our results show that environmental factors change behaviour and that these changes can be passed on to the next generation," says Isabelle Mansuy, Professor of Neuroepigenetics at the University of Zurich and ETH Zurich.
However, the researchers point out that all early childhood trauma is not positive. But they suggest that this study shows how stress doesn't affect just one generation, but the next generation as well, and fortunately, some of that results in positive effects.
This type of research opens up new ideas about how to treat some psychological illnesses that often seem passed on through families, such as depression, which affects 20 percent of the population at any given time. Research done in 2011 suggests that depression has a genetic link, and with genes being hereditary, it makes sense.
Of course, there's still a lot we don't know about these diseases, which also has causes attributed to other factors. However, knowing which gene is responsible for the positive effects that result from stress could have potential implications for future treatments for such diseases.
[Photo Credit: J.E. Theriot/Flickr]