Glucose tolerance, brain size, and tau phosphorylation in wild-type (wt), Pdx1tg, and Irs2-/-::Pdx1tg mice. a, Glucose tolerance was measured at 14 months of age. b, Brain weight at ∼14 months of age. c, Western blot analysis using phospho-tau Ser202 antibody (AT8) of whole-brain lysates at 16 months of age.