The solution that Friedman’s group hit upon, referred to as radiogenetics or magnetogenetics, avoids these problems. With their method, published last year in Nature, biologists can turn neurons on or off in a live animal at will—quickly, repeatedly, and without implants—by engineering the cells to make them receptive to radio waves or a magnetic field.
https://seek.rockefeller.edu/flipping-a-switch-inside-the-head/

http://stateofthenation.co/?p=72681