MAPT and Alzheimer disease: In studies performed by Arendt and colleagues [105], ICV infusion of OKA (70 ng/day; for up to 4 months), could replicate some AD-associated pathologies including hyperphosphorylation of tau (at Ser-202/Thr-205) and apoptotic cell death within 2 weeks, as well as cortical deposition of non-fibrillar Aβ within 6 weeks of infusion.