Optogenetic stimulation of skeletal muscle could restore patient mobility

Nature : A new technique that genetically alters muscle tissue to react to light may one day be used to treat paralysis. Philipp Sasse of the University of Bonn in Germany and his colleagues modified mice so that their muscles produced the light-sensitive protein channelrhodopsin. They then successfully used light to stimulate individual muscles in the animals’ larynx, which allowed the selective opening and closing of the vocal cords—a feat made particularly difficult because the muscles lie so close together. Light provides much more control for stimulating muscles than does electricity, which requires the implantation of electrodes. The researchers worked only with dissected organs, however, because of the difficulty involved in positioning a light source in live mice. Next they hope to try their method on live pigs, whose trachea are larger than those of mice and closer in size and shape to those of people.