CDK5 and Alzheimer disease: To further elucidate the mechanism of Se-Met in inhibiting Aβ production and tau hyperphosphorylation in the OB of 3× Tg-AD mice, we assessed the expressions of GSK-3β, phospho-GSK-3β (pGSK-3β), PP2A, phospho-PP2A (pPP2A), Akt, phospho-Akt (pAkt), and CDK5.