Simulating Brain Cells Could Lighten Up Path to Cure Parkinson’s Disease

In a fundamentally bold experiment, a research laboratory at Lund University in Sweden introduced a light sensitive protein in transgenic nerve cells transplanting nerve cells into the brains of laboratory animals. By inserting an optic nerve fibre in the brain and using it to light up the nerve cells and stimulate them into releasing more dopamine in order to control Parkinson's disease.

Parkinson's is an increasingly common disease that is triggered by the degeneration of the brain cells producing signal substance dopamine.

Though many experiments have been conducted transplanting healthy nerve cells to make up for the lack of dopamine, it was not known what happens to the transplant.

"We don't know how the new nerve cells behave once they have been transplanted into the brain. Do they connect to the surrounding cells as they should, and can they function normally and produce dopamine as they should? Can we use light to reinforce dopamine production? These are the issues we want to investigate with optogenetics," says Professor Merab Kokaia.

With the help of optogenetics the scientists can control certain cells in the brain with the help of light, thereby leaving other cells unaffected. In order to do this, the relevant cells are equipped with genes for a special light-sensitive protein. The protein makes the cells react when they are illuminated with light from a thin optic fibre which is also implanted in the brain. The cells can then be "switched on" when they are illuminated.

"If we get signals as a response to light from the host brain, 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 than 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," explains Merab Kokaia.

The researchers will obtain the light sensitive protein from a bacterium which uses light to gain energy.

"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," says Merab Kokaia.