Smaller than average baby brains that grow very rapidly in the first year of life are seen as key to the development of autism.
Small head circumference at birth, followed by a sudden and excessive increase in head circumference during the first year of life, has been linked to development of autism by researchers at the University of California, San Diego (UCSD) School of Medicine and Children’s Hospital and Health Center, San Diego. Autism spectrum disorder occurs in one out of every 160 children and is among the more common and serious of neurological disorders of early childhood.
It was found that the head size of the autistic children at birth was, on average, in the 25th percentile, meaning that the circumference measurement for these children was smaller than 75 percent of other newborns. During the first year of life, however, these same children experienced sudden, rapid and excessive brain growth, that put them in the 85th percentile at about 12- to 14-months of age. From then on, the brain growth slowed.
“This burst of overgrowth takes place in a brief period of time, between about two months and six to 14 months of age,” Courchesne said. “So, we know it cannot be caused by events that occur later, such as vaccinations for mumps, measles and rubella or exposure to toxins during childhood.”
Although no one has yet determined the biological cause of autism, the new findings “give us information about the timing of abnormal brain development,” said study co-author Ruth Carper, Ph.D., a post-doctoral researcher in the UCSD Department of Neurosciences and a research associate at Children’s. “This provides a timeframe for further research, to determine the exact brain abnormalities and the biological mechanisms which produce them.”
Is the rapid rate of brain growth a consequence of a brain growth regulatory system's sensing and responding to the fact that the brain is smaller than it ought to be?
This result will enable the detection of risk for autism at a much younger age. But what is needed is the ability to intervene in the regulatory systems that control brain growth. If research on autism leads to knowledge about how to control brain growth it may become possible to also use that knowledge to boost intelligence by intervening in baby brain development.
|Share |||Randall Parker, 2003 July 21 11:22 PM Brain Development|