I work in the field, so I thought I'd chime in here. Our lab (and others) have published a few papers on using optogenetics to control peripheral nervous system

I work in the field, so I thought I'd chime in here. Our lab (and others) have published a few papers on using optogenetics to control peripheral nervous system targets, but as some of the other commenters have mentioned, it's very much in the early stages right now, and is likely to be a long way away from human trials. A few points: 1. There are two relevant ways to make motor neurons light sensitive. As another commenter mentioned, you can create a transgenic line of animals (this is necessarily restricted to mice/rats). That's been done, and it's been shown that you can control muscle movement in such mice [1]. In that work, a rather interesting, and now replicated [2] observation was made, which is that if you use optogenetics to do this (muscle control) you actually induce less fatigue than if you use electrical stimulation to do this. Why this is the case is not yet understood. 2. The other (more relevant) way to do this would be to use viral vectors to transduce the motor neurons you want to control with the light-sensitive ion channels. We published a paper last year showing this was possible in rats [3]. The advantage here is that you can get control over individual muscles without any effect on unwanted muscles, through a subtlety of the injection method used. There are naturally many caveats here, the most important being that human gene therapy is still in its infancy, and is typically used only for very life-threatening disorders. It's also important to note that in both these cases, you still needed a way to deliver light to the relevant nerve. While there's lots of work going on to make light-sensitive ion channels even more light-sensitive, it's likely that preliminary optogenetic control of muscle will still require implants. 3. One of the applications talked about in the link here goes the other way - it's focused on delivering touch information back to the brain. There's less published here with optogenetics than there is in motor control. We've published a paper using viral methods to control sensation earlier this year (in mice) [4], but the type of sensation we were trying to control was pain, not simple touch. That said, I know that many groups are trying to develop ways to specifically make touch-transducing neurons light sensitive - I'd be surprised if we didn't see quite a few papers on this over the next year or two. [1] http://www.nature.com/nm/journal/v16/n10/abs/nm.2228.html http://www.nature.com/nm/journal/v16/n10/abs/nm.2228.html [2] http://www.sciencemag.org/content/344/6179/94.short http://www.sciencemag.org/content/344/6179/94.short [3] http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0072691 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjourna... [4] http://www.nature.com/nbt/journal/v32/n3/full/nbt.2834.html http://www.nature.com/nbt/journal/v32/n3/full/nbt.2834.html