1. Department of Physical Medicine and Rehabilitation, Harvard Medical School and Spaulding Rehabilitation Hospital Network, Brigham and Women's Hospital, and Massachusetts General Hospital, Boston, Massachusetts.
2. Department of Neurosurgery, Harvard Medical School, Boston, Massachusetts.
3. Division of SCI Research, VA Boston Healthcare System, Boston, Massachusetts.
4. Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, Brazil.