Tel Aviv University scientist Matti Mintz successfully implanted a robotic cerebellum into the skull of a rodent with brain damage, allowing it to function normally again.
http://www.newscientist.com/article/mg21128315.700-rat-cyborg-gets-digital-cerebellum.html
http://abcnews.go.com/blogs/health/2011/09/27/roborat-israelis-create-rodent-with-robot-brain/