This is wild. Chasing the elusive dream of curing paralysis, a team of scientists used stem cells and optogenetics to circumvent the central motor system of lab mice whose nerves had been cut. This enabled them to blast individual motor neurons with a laser, triggering movement in the legs of the mice.
Okay, so it's a little bit complicated, if you're not familiar with how optogenetics work (and honestly, why would you be?). The cutting-edge technique enables neuroscientists to modify specific neurons so that they're light sensitive. Shining light on the neuron then makes it fire, telling the brain to move a muscle or stop feeling pain.