[1] Med Univ S Carolina, Dept Neurosci, Charleston, SC 29425 USA
[2] Indiana Univ, Sch Med, Dept Psychiat, Indianapolis, IN 46202 USA
[3] NIA, Drug Design & Dev Sect, Intramural Res Program, Baltimore, MD 21224 USA
[4] Univ Texas Med Branch, Dept Neurol, Galveston, TX 77555 USA