Affiliation: | 1. Department of Anatomy and Neurobiology, St. Louis, MO 63100 U.S.A.;2. Department of Neurology, St. Louis, MO 63110 U.S.A.;3. Department of Pediatrics, Washington University, School of Medicine, 660 South Euclid, St. Louis, MO 63110 U.S.A. |