In organotypic hippocampal slice cultures, estradiol has been shown to reduce the kainite acid lesion-induced activation of GSK-3b and the resulting tau hyperphosphorylation [57]. Even though estradiol can reduce the effects of oxidative stress and prevent injury-induced tau hyperphosphorylation, it is not known what effect estradiol has on oxidation-induce alterations in the state of phosphorylation of tau or in protein aggregation.