With Mother’s Day just around the corner (put your cards in the mail today!), it’s a good time to revisit what articles from Dana’s archives tell us about mother-child relationships.
Some of the studies highlighted on Dana.org may seem bleak, as they study parenting in situations of abuse and neglect. But they all highlight how important a supportive, caring parent is to a developing child.
In 2005, the BrainWork article “Parenting Matters: Your Genes Prove It” discussed a study by Michael Meaney, McGill University, in which he determined that environmental epigenetic factors can alter gene expression in animal models. He studied 250 rat mothers, grouping them by frequent and infrequent lickers of their pups. Frequently-licked pups showed less fear, more willingness to explore new surroundings, and healthier stress responses into adulthood. At the biological level, Meaney found that the brains of frequently-licked pups better regulated stress hormones.
Meaney also found that interventions—having frequent lickers adopt pups previously raised by infrequent lickers—improved the behavioral outcomes of the pups.
Regina Sullivan, New York University, expanded on this topic in a 2010 Cerebrum article, “Fear in Love: Attachment, Abuse, and the Developing Brain.” A year after the BrainWork article was published, Meaney and colleagues determined that licking frequency can impact the expression of a gene involved in regulating levels of an estrogen receptor in adulthood. “Consequently,” writes Sullivan, “a rat’s sensitivity to her own estrogen levels can change, leading to changes in the way a mother handles her pups for at least two generations.”
How does this research relate to humans? Sullivan reports that “By adolescence, some 80 percent of abused children will be diagnosed with major psychiatric illness. Imaging studies of abuse survivors often show that brain areas controlling emotion and cognition are abnormal, both anatomically (they are generally smaller) and functionally.”
We also know—as reported in BrainWork in 2007—that abnormal blood sugar levels in pregnant women can lead to subtle memory problems in their children. Fortunately, pregnant women with diabetes can take steps to keep it under closer control.
And last month’s Cerebrum article explained that while fetal stress exposure can be harmful even into adolescence and adulthood, it can also be advantageous, leading to positive coping mechanisms. As the co-authors, from the University of California, Irvine, write, “consequences of maternal stress depend on the cause, timing, duration, and intensity of the stress, as well as maternal stress reactivity and the genetic susceptibility of the fetus.”
Even if a child is abused or exposed to negative stressors, there are actions that can be taken to counteract negative early exposures. Bruce McEwen, The Rockefeller University, describes some of them in a Cerebrum article and Report on Progress from 2011, “Effects of Stress on the Developing Brain”:
Programs like Head Start have worked best when the family environment supports the child and the child comes home to a stable and understanding environment. The Perry School Project is an example of this combination and has shown a large return on investment, not only in earnings and achievement for the individual but also for society, which will experience less crime, less need for special education and welfare services, and greater income tax revenue. Programs like Nurse-Family Partnership provide social support and education for first-time mothers and families, and the Harlem Children’s Zone Baby College provides this type of education in a class for expectant mothers and their partners.
McEwen also gives us more reason to thank our mothers, writing, “Strong maternal care is key to good emotional, social, and cognitive development.”