Scientists believe that the stress related to traumatic events may be passed down from parents to their children and could affect families for several generations.
Scientists claim that major shocks change the working of cells in the body and this could be passed from parent to child.
Professor Isabelle Mansuy from the University of Zurich stated that illnesses such as bipolar disorder often runs in families, but there is no trace of it to a specified gene.
Researchers have now discovered that the exposure to high stress levels causes the gene-regulating molecules’ production to be altered. The ‘microRNA’ molecules have been found in sperm and this suggests that it may be passed on to later generations.
Tests were done on mice that were exposed to very high stress levels. They displayed depressive symptoms and a slowing down of their metabolic rate. The same symptoms were evident in their offspring, although they were not exposed to the traumatic event themselves. These changes were present in third generation mice.
Professor Mansuy has said that this is the first time scientists have been able to show that traumatic events affect long-term metabolism and that the changes which occurred are hereditary. She stated that the imbalance in sperm ‘microRNAs’ has shown that trauma can be passed from one generation to the next. She further stated that it is most likely linked to a chain of events which commences with production of many stress hormones in the body.
The mice were found to behave very differently after their traumatic experiences. They appeared to lose their natural aversion to bright light and open spaces and displayed depressive behaviour.
Professor Mansuy and her team are now involved in a study of the role of ‘microRNAs’ in humans to determine if the same results would be found.
If the possibility to demonstrate that the imbalance in the blood was the cause of the trauma, it would be possible to develop a test which would diagnose inherited depression.
Image credit: Aaron Brinker