A friend recently asked me whether stem cells could be grafted into a brain to repair damage from a stroke. I didn't know the answer, so I went looking for it. This reminded me of an episode of South Park from a long time ago. In it, Cartman lobbies for the use of stem cells in order to save Kenny's life, only to reveal that all he wanted all along was to use them to clone a Shakey's Pizzaria. The reason I bring this up is because it harkens back to the first layman explanation of stem cells I ever heard back in 2001. The explanation given was that stem cells turn into whatever they're around. For many, this is still the extent of what is known. If this is true, stroke treatments make a lot of sense. To my knowledge, there are no real treatments for a stroke. A whole bunch of brain cells die and you lose the function of whatever they were needed for. Sometimes you can go through rehab to find new ways to rely on other parts of the brain, but the damaged par