1. Department of PharmacologyCollege of MedicineNational Creative Research Initiative Center for Alzheimer's DementiaNeuroscience Research InstituteMRCSeoul National University Seoul 110-799 South Korea
2. Department of Cell BiologyHarvard Medical School Boston MA 02115 USA
3. Department of MicrobiologyCollege of MedicineDivision of NeuroscienceMedical Research CenterEwha Womans University 911-1, Mok-6-dong, Yangcheonku Seoul 158-056 South Korea