Postpartum Depression Spans Generations
Daughters of female rats exhibit the same behaviors as their stressed-out moms
Social stress not only impairs a mother’s ability to care for her children; it can also hamper her daughters’ ability to care for their future offspring, according to researchers at the Cummings School of Veterinary Medicine at Tufts.
The scientists conducted a transgenerational study with female rats, examining the behavioral and physiological changes in mothers exposed to chronic social stress early in life.
To create the stress, a different male rat was placed in the cages of first-generation mothers and their newborn pups for an hour a day for 15 days. Consistent with earlier research, the mothers’ behavior changed—they were not as nurturing, produced less milk and experienced increased anxiety. The pups, too, witnessed the tension between their mothers and the male intruders.
After reaching maturation, the second-generation females were mated and assessed against a control group where neither the mother nor her pups had been exposed to a male interloper. The daughters exhibited the same behaviors as their stressed-out moms. They also experienced increases in the stress hormone corticosterone and decreases in oxytocin and prolactin (important for maternal behavior and lactation) as well as the sex hormone estradiol.
“The endocrine and behavioral data are consistent with what has been reported in studies of depressed human mothers,” says Benjamin C. Nephew, an assistant professor of biomedical sciences and principal investigator on the study, published in the September issue of Hormones and Behavior. “The potential with this animal model is that it can be used to study new preventive measures and treatments for postpartum depression and anxiety, and the adverse effects of these disorders on offspring.”