Trauma and stress experienced by one generation can also affect the next, Nature News reports.
Isabelle Mansuy from the University of Zürich and Swiss Federal Institute of Technology and her colleagues write in Nature Neuroscience that in mice, traumatic stress early in life affected their microRNA expression as well as behavior and metabolic responses in their offspring.
She and her colleagues exposed male young male mice to stress by repeatedly removing them from their mothers and placing them in either cold water or restraining them. These male mice then exhibited depressed behaviors and underestimated risk, Nature News notes. They also had abnormally high expression of five miRNAs, including miR-375, which has been linked to stress and metabolic regulation.
Additionally, Mansuy and her colleagues report that the offspring of these stressed male mice also showed depressed behaviors and abnormal sugar metabolism. They, too, had abnormal levels of those five miRNAs. The effect persisted, they add, when RNA from the traumatized mice's sperm was injected into fertilized eggs from mice that were not stressed.
According to Nature News, Mansuy and her colleagues are now exploring whether such miRNA biomarkers are present in people who experienced traumatic events or in their children
"If some are altered persistently in blood, then they could be used as markers for susceptibility to stress or for developing psychiatric disorders," Mansuy says.