APP and Cognitive impairment: In 9-month-old APP/PS1 mice treated with GV-971 for three months until 13-month old, GV-971 exhibited significant ameliorative effect on the cognitive impairment, as shown by the enhanced spatial learning and memory performance of APP/PS1 mice in both training trial (Fig. 3b) and probe trial (Fig. 3c) in the Morris Water Maze (MWM) task.