Understanding the genetic code is one thing. Altering it is something different altogether. Researchers at the Washington National Primate Research Center (WaNPRC) have discovered a technique for inserting a specific gene into the brain’s membrane, which could modify how the brain works, alter behavior, and potentially correct neurological disorders.

Researchers think that this approach, which involves genetically altering a select number of cells, might lead to treatments for neurological conditions such as epilepsy. “The brain is made up of a mix of many cell types performing different functions. One of the big challenges for neuroscience is finding ways to study the function of specific cell types selectively without affecting the function of other cell types nearby,” said lead researcher and associate professor of physiology and biophysics Gregory Horwitz. “Our study shows it is possible to selectively target a specific cell type in an adult brain using this technique and affect behavior nearly instantly.”

The research team inserted a gene into cells in the cerebellum, the parts of the brain controlling motor movements. Those cells, Purkinje cells, are some of the largest in the brain and connect with hundreds of other cellular structures.

The inserted gene, channelrhodopsin-2, creates a light-sensitive protein that inserts itself into the brain cell’s membrane. When exposed to light, the protein allows ions – tiny charged particles – to pass through the membrane.

By attaching the gene to a modified virus and painlessly injecting it into a small area of the cerebellum of rhesus macaque monkeys, the channelrhodopsin-2 was taken up exclusively by the targeted Purkinje cells. The researchers then showed that when they exposed the treated cells to light, they could affect motor control.

“This ‘transgenic’ approach has proved invaluable in the study of the brain,” Horwitz said. “But if we are someday going to use it to treat disease, we need to find a way to introduce the gene later in life, when most neurological disorders appear.” With this discovery, the researchers are one step closer to understanding the elegant system that is the brain.

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Photo credit: Kathy West for the California National Primate Research Center