Lasers used to alleviate Parkinson's disease symptoms

Written and produced by Tim Didion

SAN FRANCISCO (KGO) -- A discovery by researchers at Stanford and the Gladstone Institutes in San Francisco could someday help alleviate the symptoms of Parkinson's disease.

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.

Parkinson's Disease Research Uncovers Social Barrier

People with Parkinson's disease suffer social difficulties simply because of the way they talk, a McGill University researcher has discovered. Marc Pell, at McGill's School of Communication Sciences and Disorders, has learned that many people develop negative impressions about individuals with Parkinson's disease, based solely on how they communicate.

These perceptions limit opportunities for social interaction and full participation in society for those with the disease, reducing their quality of life. Pell's research offers the public a better understanding of the difficulties these patients face -- as well as an opportunity to promote greater inclusiveness.

The research was conducted in collaboration with Abhishek Jaywant, a research trainee in McGill's Neuropragmatics and Emotion Lab, and with financial support from the Canadian Institutes of Health Research and the Fonds de la recherche en santé du Québec. Aging adults both with and without Parkinson's were recorded as they described visual scenes. Their voices were then played to listeners who were unaware of the speaker's health status. Those with Parkinson's disease were perceived as less interested, less involved, less happy and less friendly than aging speakers without the disease. Negative impressions of their personality were specifically related to changes in the speaking voices caused by the disease, not the ability to describe the scenes.

The ability to communicate effectively is of paramount importance to the psychological well-being of all humans. This research emphasizes that problems with movement, which alter the speaking voice of Parkinsonian adults, create important social barriers and difficulties with interpersonal communication for those affected. These findings provide another avenue by which health professionals can address mental and emotional health issues in Parkinson's patients.

How key circuits in the brain control movement

A new study that has identified how key circuits in the brain control movement could treat movement related disorders, such as Parkinson’s disease. Scientists Anatol Kreitzer, PhD and Karl Deisseroth, MD PhD at the Gladstone Institute of Neurological Disease (GIND) and Stanford University used genetic methods to allow mice to produce a light-sensitive protein in very select group of cells in the brain.

Researchers found that the mouse with the fibre optics implanted in the brain moved normally with the laser turned off and froze when the laser was turned on. With the laser off, and the mouse’s movement was restored. “It’s not something we can do for just a second,” Kreitzer said. “We can do this for as long as the laser is on.” “We generated mice that lacked dopamine, and these mice showed many of the same symptoms found in humans with Parkinson’s disease. But when we activated the ‘go’ pathway in these mice, they began to move around normally again. We restored all of their motor deficits with this treatment, even though the mice still lacked dopamine,” he added.

The research could be important for treating Parkinson’s and also other disorders involving these circuits, such as Huntington’s disease, Tourette’s syndrome, obsessive-compulsive disorder, and addiction.

The research is published in the journal Nature.