A UC Irvine professor, along with a team of researchers, discovered that a marijuana-like substance naturally released in the brain can treat symptoms of one type of autism, the university recently announced.

Cannabinoids released in the brains of mice that had fragile x syndrome, one of the most common causes of genetically defined autism, treated their autistic behavior within hours of dosage, said Daniele Piomelli, a UCI professor of anatomy and neurobiology and one of the study's authors.

In conducting their research, scientists used compounds to correct signaling of the cannabinoid 2-AG in the brain, Piomelli said. Initially, researchers thought effects of the treatment would be seen over the long term, but hours later they saw something that Piomelli described as "really quite striking."

Within six hours, mice with fragile x syndrome acted differently.

Mice with the genetic difference are hyperactive, don't fear the light or open space, and don't scurry to hide when exposed as their predator-fearing cousins do, said Piomelli, who noted that humans with autism obviously don't suffer from these behavioral differences.

But like people with autism, the mice with fragile x syndrome have a difficult time adjusting or don't respond appropriately.

Treatment corrected the physiology and behavioral differences in the mice, Piomelli said. Should the stars align, treatment could be translated to humans in just a few years. More likely though, human treatment could begin anywhere between five and 10 years from now.

There are some key differences between compounds found in marijuana and those found in the brain, Piomelli said.

Marijuana is akin to a clumsy imitator compared with cannabinoids in the brain that are structurally different but functionally similar. Instead of the subtle changes in humans caused by 2-AG, the marijuana compounds have more pronounced side effects.

Piomelli teamed with researchers from France's INSERM, Istituto Italiano di Tecnologia and the Hungarian Academy of Sciences in the research.

Before this project , Piomelli studied cannabinoids for years before homing in on its application to autism. He remembers clearly the day he thought to focus his research on that potential treatment.

About two and a half years ago, he received an email from a father whose child had autism, and he remembers it verbatim.

"'I am the father of a 2-year-old girl who was diagnosed with autism,'" Piomelli said the letter read. "'I would walk through fire to find her a cure.'"

"I still have goose bumps when I think of this," he said. A father himself, Piomelli said he knew exactly how the man felt and began meeting with other scientists to work toward a cure.

lauren.williams@latimes.com

Twitter: @lawilliams30