The Changing Brain of a Neglected Child

Child neglect and isolation may alter the brain to injure cognitive and social development

(RxWiki News) Child neglect is just as serious an issue as child abuse. It can lead to serious problems later with thinking, learning and social interaction. Scientists are starting to learn why.

A recent study has shed light on exactly how social isolation can contribute to long-term brain and social problems.

"Love your children!"

The study was led by Manabu Makinodan, MD, PhD, in the Department of Neurology at Harvard Medical School and from the F. M. Kirby Neurobiology Center at Chidlren's Hospital Boston.

Dr. Makinodan and colleagues ran a series of experiments with mice to see how their brains changed in response to social isolation.

For the experiment, they isolated each mouse for two weeks when the mice were 3 weeks old. Later, they found that brain cells in the part of the brain responsible for thinking and social behavior didn't fully mature in these mice.

That part of the brain is the prefrontal cortex. It has "white matter" made up of cells that produce a substance called myelin.

Myelin is like insulation for the nerve fibers, or messengers, in your brain. It helps the messages get delivers quickly and efficiently.

The scientists found in this experiment that social deprivation early in life can stop the brain cells from making the right amount of myelin.

The researchers saw that there was less myelin insulating the mice's nerve fibers. Meanwhile, the mice displayed poor memory and poor social interaction.

This discovery matches up with what has been seen in the brains of children who were raised in extremely neglectful orphanages.

In one such study, the researchers note, the children had differences in their white matter in the same part of the brain where the mice had immature cells — the prefrontal cortex.

The prefrontal cortex is responsible for cognitive function and social interaction.

It's possible that the smaller amount of myelin might help explain the cognitive and social problems that occur in people who have experienced severe neglect or social isolation.

However, there are other theories about how myelin production problems can lead to poor thinking and social skills.

Regardless of the mechanisms, which the researchers are still studying, this experiment also revealed that it makes a difference when neglect occurs.

The mice were able to recover thinking and social skills when they were returned to a social environment — as long as they had not been isolated during a critical period of their development.

However, if they were isolated during a specific period of important development, they never fully recovered.

"Having both too much and too little myelination is bad," said co-author Gabriel Corfas, PhD, in a release. "This is a pathway that requires very careful regulation."

He and Dr. Makinodan are now seeking to find out if they can develop drugs that will work in that pathway.

The same myelination problems have been linked to schizophrenia and mood disorders as well, so any effective drugs could have broader application if successfully developed.

"This research offers some very important information for understanding brain development in infants and preventing serious psychiatric and related problems later," said LuAnn Pierce, a clinical social worker in Colorado.

"We have known that attachment and bonding in the first few months of life are critical to psychosocial development," Pierce said. "However, this very specific information about the formation of myelin in those critical early weeks opens up a new understanding of how and why deprivation in infancy causes these and other cognitive problems."

The study was published September 13 in the journal Science. The study was funded by the National Institute of Neurological Disorders and Stroke, an NIH Intellectual and Developmental Disabilities Research Center grant and Nara Medical University.

Review Date: 
September 12, 2012