Skin cells are not part of the nervous system, they apparently use rhodopsin just to regulate melanin. You can make any part of the brain photosensitive by inje

Skin cells are not part of the nervous system, they apparently use rhodopsin just to regulate melanin. You can make any part of the brain photosensitive by injecting Channelrhodopsin viral vectors, that's an exciting recent experimental area called optogenetics.