Constant stress during pregnancy wipes out all the benefits of brain development during motherhood related to learning, memory or mood leading to postpartum depression, researchers reveal.
Lead author Benedetta Leuner of Ohio State University and colleagues examined growth of dendritic spine - the hair like growth on brain cells help in exchanging information with other neurons and improve the cognitive function related to multitasking- on rats.
They found brains of mother rats that were stressed at least twice a day lacking an increase in the brain cell connections and possessing brain characteristics similar to animals without reproductive or maternal experience.
"Animal mothers in our research that are unstressed show an increase in the number of connections between neurons. Stressed mothers don't," Leuner, assistant professor of psychology and neuroscience at Ohio State, said in a news release. "We think that makes the stressed mothers more vulnerable. They don't have the capacity for brain plasticity that the unstressed mothers do, and somehow that's contributing to their susceptibility to depression."
For analyzing the impact of stress during pregnancy, Leuner and team conducted some experiments on pregnant rats. They were subjected to stress twice daily by putting some restrictions on their mobility or by keeping them in water.
The animals were kept under examination for three weeks after giving birth. The low weight gain and enlarged adrenal glands showed high stress hormone production in these rats. Pups of the stressed mothers were also smaller in size.
According to the researchers chronic stress can be included in the long list of risks factors for postpartum depression. Apart from that, the researchers found the stressed mothers least bothered about their pups, unlike unstressed mothers.
"And they were not very good mothers," Leuner said. "It's devastating not only for the mother, because it affects her well-being, but previous research also has shown that children of depressed mothers have impaired cognitive and social development, may have impaired physical development, and are more likely as adults to have depression or anxiety."
Leuner presented the findings at the annual meeting of the Society for Neuroscience, on, Oct. 13.
