Optogenetics assists in fight against Parkinson's disease

31 Oct 2012

Lund University will use the technique to study the behavior of transplanted cells in laboratory rats.

A research project underway at Lund University and funded by the Michael J. Fox Foundation will use optogenetics to monitor the effectiveness of transplanted cells in combating the effects of Parkinson's disease, the latest step in the use of the technique to study this condition.

The team led by Merab Kokaia proposes to take human skin cells and modify them to act as nerve cells, a "reprogramming" step known as transdifferentiation and which involves introducing new foreign genes into the cell.

Each cell will also be equipped with genes for a light-sensitive protein, which allows them to react when irradiated with light, in this case blue light from a laser or LED supplied via optical fiber. This responsiveness, and the ability to target it onto specific cells of interest, is the basis of optogenetics.

Once prepared, the cells will be transplanted into the brains of laboratory rats modeling Parkinson's disease.

"This is the first time such an approach is going to be used," said Kokaia. "If we get signals from the host brain as a response to light, we know that they come from the transplanted cells since they are the only ones to carry the light-sensitive protein. This gives us a much more specific way of studying the brain's reactions compared to inserting an electrode, which is the current method. With an electrode, we do not know whether the electric signals that are detected come from 'new' or 'old' brain cells."

Dopamine release
One particular goal is to investigate more fully the factors affecting the release of dopamine, a chemical responsible for transmitting the signals within the brain that allow for coordination of movement, and one therefore of keen interest to researchers hoping to understand Parkinson's disease.

"The principle is that optogenetic stimulation or activation of the cells would increase release of dopamine from these cells," Kokaia commented to Optics.org. "Dopamine is the main neurotransmitter that is in short supply in Parkinson's disease, since the cells producing dopamine die. Our idea is to transform cells derived from human skin into neurons that can produce dopamine, and then use optogenetics to try to increase dopamine release from these transplanted cells."

Although this ambition might still be some way off, Kokaia believes that the approach is a sound one as a route to tackle the disease. "We know that this is long term research, but the methodology is interesting and it will be exciting to see what we can come up with," he said.

The Michael J. Fox Foundation agrees, and has provided a grant of $75,000 to the project. Established by actor Michael J. Fox in 2000, the Foundation has invested over $300 million towards combating Parkinson's disease, and is said to be the largest private funder of research into the condition in the world.