RB1 and memory impairment: The non-spatial memory improvement effect of Rg1 was reported in previous researches, which found Rg1 improved scopolamine (SCOP) induced memory impairment in a step-through test (Yu-Zhu Wang et al., 2009) and both Rg1 and Rb1 can improve the impaired memory performance induced by SCOP in step-down passive avoidance test (Wang et al., 2010).