Dad's Stress Linked with Altered Brain Function in Children

A dad's stress can have a negative impact on the child's brain, according to a new study. Researchers found that stress that affects a father even during his teen years can be detrimental to his child's well-being.

It is known that stress that affects mothers can cause significant health complications in the child. Now, researchers from University of Pennsylvania have found a link between father's stress and depression in children.

The latest study was conducted on a set of mice. Researchers found that stress left a genetic mark on the male's sperm, which was later passed to its offspring, where it altered the function of hypothalamic-pituitary-adrenal (HPA) axis - the region in the brain that controls the reaction to stress. This abnormality to stress response was seen in both male and female pups.

"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. These findings suggest one way in which paternal-stress exposure may be linked to such neuropsychiatric diseases," said Tracy L. Bale, PhD, associate professor of neuroscience in the Perelman School of Medicine Department of Psychiatry and lead author of the study.

Male mice were chosen for the study because they don't play any role in taking care of the pups. For the study, these mice were subjected to chronic stress before breeding, either throughout puberty or only in adulthood. Few examples of stressors for the mice include being moved to a different cage, exposure to the odor of a predator, or a foreign object in the cage.

Researchers found that the pups of male mice subjected to stress had poor response to stress.

To understand this stress response, researchers looked at the changes in the activity of genes in certain regions of the brains known to be associated with stress called the paraventricular nucleus (PVN) and the bed nucleus of stria terminals.

Researchers found an increased activity of glucocorticoid-responsive genes in the PVN, which could explain the poor sensitivity to stress.

The researchers also analyzed a series of microRNAs (miRs) in the male mice's sperms that could contribute to this changed behavior in the offspring. According to the authors, these genetic markers inform the pups about the environment. The early warning is designed to help the pup cope with the environment, according to a news release.

"Whether such diminished stress reactivity would be detrimental or beneficial to offspring likely depends on the environment into which they were born, as well as genetic background factors," they wrote in the paper.

The study is published in the Journal of Neuroscience.