On Thursday, NBC will air the sixth episode of its new comedy series, "The Michael J. Fox Show." In it, Fox plays a popular television anchorman who returns to work after having retired years earlier because of his Parkinson's disease. This, of course, closely tracks Fox's own story. An extremely well-liked actor, he last starred in a television series in 2000, which is when the tremors, stiffness and involuntary body movements that are associated with Parkinson's forced him to retire from "Spin City."