WASHINGTON

AFP

People with autism have too many synapses — the connectors by which brain cells send and receive signals — according to a new study that may point to a treatment for the complex disorder.

The extra synapses in autistic brains are the result not of overproduction, but of a failure in the normal process of discarding old and degraded cells.

Researchers at New York’s University of Columbia were able to re-establish the brain’s “pruning mechanism” in mice genetically modified to simulate autism.

To do it, they used a drug called rapamycin to block a protein, mTOR, which in autistic patients goes hyperactive and blocks the brain’s natural ability to cull synapses. The researchers saw a reduction in typical autistic behaviors, such as avoiding contact with others, in the treated mice, according to findings published this week in the US journal “Neuron.” “We were able to treat the mice after the disease had appeared,” said Columbia University neurobiologist David Sulzer, lead author of the study.

This is crucial because autism does not become apparent at birth but later in childhood, “so you need a treatment that works after diagnosis,” he said.

“If we were correct we should be able to have quite effective treatment even after diagnosis,” he told AFP.

One in 68 US children is diagnosed on the autism spectrum, according to the most recent government estimates.