Wednesday, January 6, 2010
New tools that use dissimilar colors of light to silence brain activity can lead to new treatments for disorders like epilepsy, chronic pain, Parkinson's disease and brain injury, neuroscientists say.
These so-called "super-silencers" give precise control over the timing of the shutdown of overactive brain circuits, something that is impossible with existing drugs or other conventional treatments, as said by the research team from the Massachusetts Institute of Technology.
The research is published in the January 7 issue of the journal Nature.
"Silencing different sets of neurons with different colors of light allows us to understand how they work together to implement brain functions," study senior author Mr. Ed Boyden, a professor in the MIT Media Lab also an associate member of the McGovern Institute for Brain Research at MIT, said in a news release.
"Using these new tools, we can look at 2 neural pathways and study how they compute together. These tools will help us comprehend how to control neural circuits, leading to new understandings and treatments for brain disorders -- some of the biggest unmet medical needs in the world," Ed Boyden added.
He and his colleagues developed the super-silencers using 2 genes called Arch and Mac that are found in unlike organisms such as bacteria and fungi. The genes encode for light-activated proteins that help organisms make energy. The activity of neurons engineered to convey Arch and Mac can be inhibited by shining light on them. The light activates the proteins, ensuing in lower voltage in the neurons, which prevents them from firing effectively, Ed Boyden explained.
Yellow light silences Arch whereas blue light silences Mac.
"In this way, the brain can be programmed with different colors of light to identify and possibly correct the corrupted neural computations that lead to disease," study co-author Mr. Brian Chow, a postdoctoral associate in Boyden's lab, said in the news release.
