MAPT and tauopathy: To determine whether cofilin normally promotes tauopathy in vivo, we performed immunohistochemistry (IHC) for phospho-tau (pS396/pS404 and pS199/pS202) in the hippocampus and cortex of 7-month-old WT, Tau-P301S, and Tau-P301S;cofilin+/− littermates.