Afraid of heights?
Study suggests phobias may be inherited from past generations
In seeking to explain why some people suffer from apparently irrational phobias, scientists have discovered that individual fears may be passed down from one generation to the next, suggesting it is possible that some memories may be biologically transmitted.
Researchers from the Emory University School of Medicine in Atlanta conditioned several mice to link fear with the smell of orange blossoms by administering an electric shock whenever the smell was present.
Whentheoffspringofthose mice were presented with the smell of orange blossoms, researchers found that they, too, showed signs of fear, despite never having encountered the scent of orange blossoms before.
A similar reaction of fear was seen in the grandchildren of the original parent mice, and in subsequent generations.
The researchers found an actual physical change in the brains of these mice, in the area used to detect the scent of orange blossoms.
“From a translational perspective, our results allow us to appreciate how the experiences of a parent, before even conceiving offspring, markedly influence both structure and function in the nervous system of subsequent generations,” Dr. Brian Dias, from Emory University’s department of psychiatry, told London’s Daily Telegraph.
“Such a phenomenon may contribute to the ... potential intergenerational transmission of risk for neuropsychiatric disorders such as phobias, anxiety and post-traumatic stress disorder.”
The study, which was published in the journal Nature Neuroscience, found that sperm cells alone can transmit fear responses.
Prof. Marcus Pembrey, a pediatric geneticist at University College London, said the study’s findings could be applied toward building a more complex understanding of neuropsychiatric disorders, such as obesity and diabetes.
“It is high time public health researchers took human trans-generational responses seriously,” Pembrey told the Telegraph.