1. Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA
2. Departments of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA 98195, USA
3. Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
4. Neurology, University of Washington School of Medicine, Seattle, WA 98195, USA
5. Pharmacology, University of Washington School of Medicine, Seattle, WA 98195, UA
6. Alzheimer's Research Center, Regions Hospital, St. Paul, MN 55101, USA