Disorganized Brain Cells Help Explain Autism Symptoms
During the second and third trimester of pregnancy, the outer layer of the embryo's brain, the cortex, assembles itself into six distinct layers. But in autism, according to new research, this organization goes awry—marring parts of the brain associated with the abilities often impaired in the disorder, such as social skills and language development.
Eric Courchesne, director of the Autism Center of Excellence at the University of California, San Diego, and his colleagues uncovered this developmental misstep in a small study that compared 11 brains of children with autism who died at ages two through 15 with 11 brains of kids who died without the diagnosis. The study employed a sophisticated genetic technique that looked for signatures of the activity of 25 genes in brain slices taken from the front of the brain—an area called the prefrontal cortex—as well as from the occipital cortex at the back of the brain and the temporal cortex near the temple.