A U.S. university has found an innovative way of using LED lights. With the flick of a light switch, researchers at the Salk Institute for Biological Studies can change the shape of a protein in the brain of a mouse, turning on the protein at the precise moment they want. This allows the scientists to observe the exact effect of the protein's activation. The new method, described in the Oct. 16, 2013, issue of the journal Neuron, relies on specially engineered amino acids—the molecules that make up proteins—and light from an LED.