AKT1 and Alzheimer disease: In agreement with that notion, we consistently observed in the cortex and the hippocampus of two different AD transgenic mice models an age-dependent increase in the levels of PDK1 activity, as judged by the elevated levels of auto-phosphorylation at the Ser241 within the PDK1 activation loop as well as the elevated phosphorylation of the downstream Akt substrates.