Lasers used to alleviate Parkinson's disease symptoms


They have mapped the pathways of the brain associated with the disease and the key to their breakthrough is laser light.

It may not look as dramatic as the light sabers in Star Wars, but Anatol Kreitzer believes this laser someday become a powerful weapon in the war against Parkinson's disease.

In his lab at San Francisco's Gladstone Institutes' Kreitzer's team is using lasers to manipulate neural pathways in the mice's brains whose cells have been genetically altered to respond to laser light.

A research assistant applies laser light to stimulate the neurons in a sample of living brain tissue, which is magnified on the screen.

The data collected has allowed Kreitzer's team to not only map specific neural pathways, but also identify their role in controlling movement. An interruption of that neuron function is believed to play a key role in diseases like Parkinson's.

"When we can identify the neural circuitry involved these diseases, then we can target it more specifically with drugs," Kreitzer said.

Researchers also believe the lasers could eventually have a more direct use. Not just as a research tool, but as an actual treatment for Parkinson's.

The current study builds on the work of Stanford University researcher Dr. Karl Deisseroth.

Last year, Deisseroth showed us how he was able to use laser light applied directly to a lab animal's brain to turn its dopamine receptors on and off first by addicting the animal to a substance and then reversing the craving and un-addicting it.

"And we use laser light to control, to tune and modify the behavior of brain cells," he said.

Collaborating with Deisseroth, the research team at Gladstone used that same technique, to turn neural pathways associated with Parkinson's on and off.

"We can do two things: We can actually simulate Parkinson's disease, we can cause mice to freeze. But we can also take mice that have Parkinson's disease and activate another pathway, and we can actually relieve the symptoms of that Parkinson's disease," Kreitzer said.

He envisions a day when the lasers might be used as an alternative form of deep brain stimulation. That's a therapy where electrodes which are surgically implanted to help control brain function in Parkinson's patients.

"Sometime in the future we can put things like diodes that are in an L.E.D. television, very small. You can imagine implanting those in the brain and using them to active neurons," Kreitzer said.

While implanting light sources in the human brain may be years or decades away, the technology is giving researcher their first chance to test out theories of how neural pathways interact.

The team believes other neural-based diseases like Huntington's and Tourette's syndrome may also be candidates for research using this laser light technique.

Written and produced by Tim Didion

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