It may sound like a bad dream or maybe science fiction, but brain researchers have been speculating for years about an assumption that makes them think about it: are trauma inherited from one generation to the next? And if so, how?
The simple fact of asking this question is a curious event, since it has been shown that stress or trauma do not modify the sequence of the components of the genetic material of DNA. It is a clear example that the classical laws of transmission formulated by Mendel do not always work. However, scientists continue to wonder about the mechanisms of transmission of trauma in humans.
Isabelle Mansuy leads a research team at the University of Zurich that is dedicated to analyzing this question. The results of their experiments have revealed that trauma could be passed from generation to generation through what is known as micro-RNA , a type of single-stranded RNA that has the ability to control the frequency of expression of certain genes.
The Zurich team showed that, for example, stress is capable of greatly modifying the concentration of micro-RNA in the sperm of mice , while their behavior is also affected. With this, the mice in the experiment were not the only animals to present striking behaviors, since these also appeared in their offspring, despite the fact that they had never been subjected to a stressful situation. The progeny exhibited depressive behaviors that persisted even into the third generation, in addition to a series of failures in sugar metabolism.
The first and second generations also had abnormal levels of the five microRNAs studied in both the blood and the hippocampus, a region of the brain involved in stress responses. The study was published in the journal Nature Neuroscience .
