Lighting Up Your Muscles

Researchers at Stanford University have found a way to move muscles with pulses of light, reports Technology Review's Erika Jonietz. The study, published in Nature Medicine, describes what the researchers are calling "optogenetics" — a technology which uses light-sensitive proteins from a single-celled alga placed on the nerve and pulses of light to trigger muscle movement, Jonietz says. The researchers insert the gene for a protein called channelrhodopsin-2, which comes from green algae. Then when the neuron implanted with the gene is exposed to blue light, the protein starts a chain of electrical activity inside the cell which spreads to surrounding neurons. "By controlling which neurons make the protein, as well as which cells are exposed to light, scientists can control neural activity in living animals with unprecedented precision," she adds. By implanting a small LED cuff into the mice, the researchers were able to apply light to the nerve evenly. The research could eventually lead to better therapies for the paralyzed, or for patients with neuromuscular disorders, Jonietz says.