Children and Adolescents with Autism Have Extra Synapses in Their Brains

Scientists have taken a closer look at children and adolescents with autism and have found that they actually have a surplus of synapses in their brains. This excess could actually be due to a slowdown in a normal brain "pruning" process during development, and could have profound effects on how the brain functions.

"This is an important finding that could lead to a novel and much-needed therapeutic strategy for autism," said Jeffrey Lieberman, director of New York State Psychiatric Institute, who wasn't involved in the study, in a news release.

In fact, a drug has already been developed that restores normal synaptic pruning and improves autistic-like behaviors in mice. Called rapamycin, the drug has side effects that may preclude its use in people with autism. Yet due to the changes seen in mice, scientists are hopeful of the possibility of potentially treating autism after a child is diagnosed with a better drug.

The researchers made the discovery after examining the brains of children with autism who had died from other causes. Thirteen brains came from children ages two to 9, and 13 came from children ages 13 to 20. The scientists found by late childhood, spine density had dropped by about half in the control brains, but by only 16 percent in the brains from autism patients. More specifically, the scientists found that autistic children's brain cells were filled with old and damaged parts and were very deficient in a degradation pathway known as "autography," which cells us to degrade their own components.

"It's the first time that anyone has looked for, and seen, a lack of pruning during development of children with autism," said David Sulzer, one of the researchers. "although lower numbers of synapses in some brain areas have been detected in brains from older patients and in mice with autistic-like behaviors."

The findings reveal a potential avenue to treat autism in children in the future. This could have enormous implications for future research and therapies.

The findings are published in the journal Neuron.