A novel way of studying neural circuits
Berkeley, CA. Scientists have long known that brain cells don’t work in isolation. They form complex neural networks that control everything from breathing to behavior. However, researchers wanting to understand how the brain works have for years been stymied by one major technological hurdle: they can only measure the activity of one brain cell at a time.
Stanford University’s Karl Deisseroth has created a novel way of studying neural circuits that promises to revolutionize our understanding of brain function. The method, called optogenetics, even shows potential as a treatment for brain disorders, like Parkinson’s disease.
In honor of these seminal findings in brain research, Deisseroth has been named the recipient of the 2009 Golden Brain Award by the Berkeley, California-based Minerva Foundation.
“Optogenetics is a truly novel and innovative approach to understanding how specific neural circuits regulate behavior, and even complex phenomenon such as emotions,” said Elwin Marg, professor emeritus of vision sciences at the University of California Berkeley and co-founder of the Minerva Foundation.
Optogenetics is a technique used to directly control brain cell activity with light. In the lab, Deisseroth and his team insert genes for producing light-sensitive proteins into cells of interest. One gene, (ChR2) derived from algae, makes affected neurons more active when exposed to blue light. Another gene (NpHR), which is borrowed from a microbe called an archaebacterium, can make neurons less active in the presence of yellow light.
Combined, the two genes make neurons obey pulses of light like drivers obey a traffic signal: Blue means “go” (emit a signal), and yellow means “stop” (don't emit). The pulses of light are delivered via a thin, flexible fiber-optic cable placed deep into the brain of the animal. The animals move and behave freely during experiments.
“This research provides a tool that we didn't have before, which is precise on-or-off control over specific neural cells in living creatures and intact circuits," said Deisseroth, an associate professor of bioengineering and psychiatry when describing his work in 2007. “This gives us the power to ask what the causal role of specific cell types is in neural circuit function,” he said.
Deisseroth has been busy collaborating with colleagues, both in the U.S. and abroad, to apply this technique to a variety of biological questions. In 2007, then National Institutes of Health Director Elias A. Zerhouni called Deisseroth’s work “…a prime example of the highly innovative approaches to major challenges in biomedical research…” and “…a key step toward the important goal of mapping neural circuit dynamics…”