PGL-1 fraction, containing glycoproteins with low molecular weight, at 40, 80 and 160 mg/kg/d ip for 35 d following Aβ25–35 bilateral injection in hippocampus prevented decline in MWM performance [132]; the same effect on MWM was observed after 6 wk of Rg2 at 25, 50 and 100 mg/kg/d on the same experimental model [133] and after Rg1 at 5, 10, and 20 mg/kg/d for 25 d following AD induction by icv okadaic acid—an inhibitor of the protein phosphatases PP1 and PP2A that are involved in the tau protein-hyperphosphorylation hallmark of AD [134]. Here, MAPT is linked to Alzheimer disease.