Memories can be inherited
The long-term effects of traumatic events may not just be a health concern of the moment.
Scientists believe the incidences could alter a person’s DNA and the genetic changes then inherited by later generations.
The process may even be an underlying cause for the development of phobias and anxiety.
US researchers, from Emory University School of Medicine in Atlanta, found that information learned during traumatic or stressful life events and experiences can be passed on genetically to subsequent generations.
These inherited experiences may explain why many people suffer from seemingly irrational fears.
Astonishingly this process, known as trasgenerational epigenetic inheritance, can begin even before conception.
“The experiences of a parent, even before conceiving, markedly influence both structure and function in the nervous system of subsequent generations,” the researchers wrote.
The study, published in Nature Neuroscience, examined the genetic phenomenon in mice. A group of the animals was ‘trained’ to fear a particular smell – similar to that of a cherry blossom.
Subsequent generations, the mice’s offspring and their offspring, were found to be ‘extremely sensitive’ to the same smell despite never having experienced it before for themselves.
Changes in the mice’s DNA and brain structure were also noted, and the scientists believe, helped to explain the genetic alteration that caused the smell-aversion and which was then passed down.
“This might be one mechanism that descendants show imprints of their ancestor,” Dr Brian Dias, one of the study’s researchers told reporters.
“There is absolutely no doubt that what happens to the sperm and egg will affect subsequent generations,” he added.