1. Department of Neurology, University of Maryland, and Department of Veterans Affairs and Research Service, Department of Veterans Affairs Medical Center, Maryland VA Medical Center, Baltimore, MD 21201
2. Research Service, Department of Veterans Affairs Medical Center, Baltimore, Maryland VA Medical Center, Baltimore, MD 21201
3. Department of Cell Biology, University of Texas, Houston, TX
4. Genetic Pharmacology Unit, Experimental Therapeutics Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD 20892-1406