1. Mental Health Service, VA Boston Healthcare System, Brockton, Massachusetts.
2. Department of Psychiatry, Boston University School of Medicine, Boston, Massachusetts.
3. Department of Pharmacology and Experimental Therapeutics, Boston University School of Medicine, Boston, Massachusetts.
4. Research Service, VA Boston Healthcare System, Jamaica Plain, Massachusetts.
5. Division of Spinal Cord Injury Research, VA Boston Healthcare System, West Roxbury, Massachusetts.
6. Departments of Physical Medicine and Rehabilitation and Neurosurgery, Harvard Medical School, Boston, Massachusetts.
7. Research Service, VA Boston Healthcare System, West Roxbury, Massachusetts.