How social deprivation during early childhood impairs brain functions

Previous studies have shown that children who suffer severe neglect and social isolation have cognitive and social impairments as adults.

Now, research from Boston Children's Hospital has revealed, for the first time, how these functional impairments arise.

Social isolation during early life prevents the cells that make up the brain's white matter from maturing and producing the right amount of myelin, the fatty "insulation" on nerve fibers that helps them transmit long-distance messages within the brain, the study found.

It also identifies a molecular pathway that is involved in these abnormalities, showing it is disrupted by social isolation and suggesting it could potentially be targeted with drugs. Finally, the research indicates that the timing of social deprivation is an important factor in causing impairment.

The researchers, led by Gabriel Corfas, PhD, and Manabu Makinodan, MD, PhD, both of the F.M. Kirby Neurobiology Center at Boston Children's Hospital, modeled social deprivation in mice by putting them in isolation for two weeks.

When isolation occurred during a "critical period," starting three weeks after birth, cells called oligodendrocytes failed to mature in the prefrontal cortex, a brain region important for cognitive function and social behavior. As a result, nerve fibers had thinner coatings of myelin, which is produced by oligodendrocytes, and the mice showed impairments in social interaction and working memory.

Studies of children raised in institutions where neglect was rampant, including another recent study from Boston Children's Hospital, have found changes in white matter in the prefrontal cortex, but the mechanism for the changes hasn't been clear. The new study adds to a growing body of evidence that so-called glial cells, including oligodendrocytes, do more than just support neurons, but rather participate actively in setting up the brain's circuitry as they receive input from the environment.

"In general, the thinking has been that experience shapes the brain by influencing neurons," explained Corfas, the study's team leader and senior investigator, who also holds an appointment in the Departments of Neurology and Otolaryngology at Boston Children's Hospital and Harvard Medical School.

... contd.

ALSO READ

Facebook can make you mentally ill?

In treating cancer, Genes Matter

Obama backs FDA decision on morning-after pills

New blood test may predict Alzheimer's disease