How 'Good Mothering' Hardwires a Child's Brain: Mom Impacts Her Babies

Could having a good mother impact a child's brain? That just may be the case, according to a new study. Researchers have taken a look at rat pups and have found that their mothers and their nurturing roles directly mold the early neural activity and growth of their offspring's brains.

Scientists have known for years that maternal-infant bonding impacts neural development. Yet in this latest study, researchers have taken it one step further. They've found that natural, early maternal attachment behaviors, including nesting, nursing and grooming of pups, impact key stages in postnatal brain development.

In this case, the scientists examined a half-dozen rat mothers and their litters. They watched and videotaped these rats from infancy for preset times during the day as they naturally developed. One pup from each litter was outfitted with a miniature wireless transmitter, which was invisibly placed under the skin and next to the brain to record electrical patterns.

"Our research shows how in mammals the mother's sensory stimulation helps sculpt and mold the infant's growing brain and helps define the role played by 'nurturing' in healthy brain development, and offers overall greater insight into what constitutes good mothering," said Regina Sullivan, the senior study investigator, in a news release. "The study also helps explain how differences in the way mothers nurture their young could account, in part, for the wide variation in infant behavior among animals, including people, with similar backgrounds or in uniform, tightly knit cultures."

More specifically, the researchers found that when rat mothers left their pups alone in the nest, infant cortical brain electrical activity jumped 50 percent to 100 percent and brain wave patterns became more erratic. This type of periodic desynchronization is actually key to healthy brain growth. During nursing, in contrast, brain activity slowed and become more synchronous and slow-wave infant brain activity increased by 30 percent.

"There are so many factors that go into rearing children," said Emma Sarro, lead study investigator. "Our findings will help scientists and clinicians better understand the whole-brain implications of quality interactions and bonding between mothers and infants so closely after birth, and how these biological attachment behaviors frame the brain's hard wiring."

The findings are published in the journal Current Biology.