Trauma Follows Generations
Did you serve in the military? Maybe you witnessed something traumatic at home, or you had a bad accident. It turns out that if it is extremely traumatic and sticks with you, chances are it will get passed on to your children. The findings come from a new study from the University of Zurich and ETH Zurich and they even have some ideas as to why it gets passed on.
Traumatic experiences can cause behavioral changes, this is nothing new if you are familiar with the coverage on disorders like PTSD, but only recently have people realized that the trauma has an effect that gets passed down generations, “There are diseases such as bipolar disorder, that run in families but can’t be traced back to a particular gene,” explains Isabelle Mansuy, professor at ETH Zurich and the University of Zurich.
So what is causing the change in behavior? It turns out it isn’t genes [your DNA] or even your epigenetics [How those genes are read], it’s something called microRNA.
When your DNA is read to do something in the body a small portion [the part that is read] is copied, the result is RNA, RNA is similar to DNA, but should not be confused since they serve two different functions. RNA is more like a copy of instructions you wrote since you need to keep the original for yourself.
MicroRNA is [comparatively] small RNA which serve different functions in the body and can be found circulating in the blood. What researchers did was study the different types of microRNA in the blood and the levels from mice who had traumatic conditions in early life and compared that information to mice that did not have any sort of early life trauma.
What they found was that trauma affects levels of microRNA in the blood, brain and sperm — while some microRNAs were produced in excess, others were found to be lower than in the levels of the control animals.
After traumatic events the mice had much different behavior– avoiding light, open spaces and they expressed depressive behaviors. These traits were then passed on to the next generation via sperm. So that the offspring mice behaved in the same way.
That wasn’t the only thing affected, the metabolism of the offspring of stressed mice was also changed: their insulin and blood-sugar levels were lower than in the offspring of non-traumatized parents.
“We were able to demonstrate for the first time that traumatic experiences affect metabolism in the long-term and that these changes are hereditary,” says Mansuy. The effects on metabolism and behaviour even persisted in the third generation. “With the imbalance in microRNAs in sperm, we have discovered a key factor through which trauma can be passed on,” explains Mansuy.
Mansuy and her team are now conducting more tests, this time with humans. The goal is to create a type of blood test to help diagnose the issue, with hope this new line of study just might help treat people who suffer from traumatic effects.
Want more detail? You can find the full study — here!