Hippocampal tissues of patients with AD (Braak V and VI; aged 71 to 93 years; postmortem intervals, 2 to 16 hours) and age-matched control were supplied by the Harvard Brain Tissue Resource Center (McLean Hospital, Boston). Hippocampal tissues of patients with AD were homogenized in ice-cold tris-buffered saline containing of 20 mM tris-Cl (pH 7.4), 150 mM NaCl, and protease inhibitors. The homogenates were clarified by centrifugation at 4°C, aliquoted, and stored at −70°C. The supernatants were resolved by SDS-PAGE.