PHILADELPHIA Sperm doesn't appear to forget anything. Stress felt by dadwhether as a preadolescent or adultleaves a lasting impression on his sperm that gives sons and daughters a blunted reaction to stress, a response linked to several mental disorders. The findings, published in a new preclinical study in the Journal of Neuroscience by researchers at the University of Pennsylvania, point to a never-before-seen epigenetic link to stress-related diseases such as anxiety and depression passed from father to child.
While environmental challenges, like diet, drug abuse, and chronic stress, felt by mothers during pregnancy have been shown to affect offspring neurodevelopment and increase the risk for certain diseases, dad's influence on his children are less well understood. The effects of lifelong exposures to dad on children are even more out of reach.
Now, a team of researchers led by Tracy L. Bale, PhD, associate professor of neuroscience in the Perelman School of Medicine Department of Psychiatry and the School of Veterinary Medicine Department of Animal Biology have shown that stress on preadolescent and adult male mice induced an epigenetic mark in their sperm that reprogrammed their offspring's hypothalamic-pituitary-adrenal (HPA) axis, a region of the brain that governs responses to stress. Surprisingly, both male and female offspring had abnormally low reactivity to stress.
This stress pathway dysregulationwhen reactivity is either heightened or reducedis a sign that an organism doesn't have the ability to respond appropriately to a changing environment. And as a result, their stress response becomes irregular, which can lead to stress-related disorders.
"It didn't matter if dads were going through puberty or in adulthood when stressed before they mated. We've shown here for the first time that stress can produce long-term changes to sperm that reprogram the offspring HPA stress axis regulation," said Bale.
|Contact: Steve Graff|
University of Pennsylvania School of Medicine