Affiliation: | 1. Department of Biology, Swarthmore College, Swartmore, PA 19081 U.S.A.;2. Department of Neurology, Montefiore Hospital and Medical Center, Bronx, NY 10467 U.S.A.;3. Department of Rehabiltation Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032, U.S.A. |