The story of mammalian neural transplantation really begins eighty-one years ago. In Chicago in December of 1903, a 34-year-old physician, Elizabeth Hopkins Dunn, working as a research assistant in neurology, initiated a series of experiments to examine the ability of neonatal rat cerebral tissue to survive transplantation into the brain of matched littermates. Out of 46 attempts, four clearly successful grafts were identified. The publication of Dunn's results in 1917, the first credible report to demonstrate the feasibility of mammalian CNS transplants, generated little interest. In fact,...