Problems With Pre-Birth Brain Growth Linked To Autism
In the ongoing quest to find a cause for autism, researchers have left few paths uncovered, and yet we still aren't sure why some children develop autism while others remain immune. Now a new study partly funded by the National Institutes of Health (NIH) has learned something new. Children who are diagnosed with autismhave more brain cells and heavier brains compared to typically developing children, who don't have autism. The study, published in the Journal of the American Medical Association on Nov. 9, 2011, while small, does provide some actual direct evidence for a possible prenatal causes of autism. Thomas R. Insel, M.D., director of the National Institute of Mental Health (NIMH), part of NIH, says the following:
"Earlier studies of head circumference and early brain overgrowth have pointed us in this direction, but there have been few quantitative neuroanatomical studies due to the lack of post-mortem tissue from children with autism. These new results, along with an earlier study reporting altered wiring of the prefrontal cortex, focus our attention on this critical area of the brain in autism."
The prefrontal cortex is a part of the brain involved in various higher order functions such as language and communication, social behavior, mood, and attention. Most children with autism showcase deficits in these functions. Researchers conducted direct counts of brain cells in specific regions of the prefrontal cortex in brains of boys who had autism, along with six typically developing boys without autism, and found that the boys with autism had 67% more neurons in the prefrontal cortex and heavier brains for their age when compared to the boys without autism. Neurons are created before birth, which is a key element of this research, as it shows a timeline of events leading up to autism. The researchers have two guesses about the study - one is that perhaps faulty prenatal cell birth could be linked to the development of autism. A second theory is that reduced cell death, a process that normally occurs during the third trimester and early postnatal life, but may not be occurring in children who develop autism. A much larger number of brain samples are needed to confirm these findings and to identify patterns of age-related changes in autism, but even so, this is very encouraging research, as few direct issues have been linked to autism development. The sooner researchers can find an ongoing direct link, the sooner they can also perhaps find a way to prevent autism from developing.