MAPT and Alzheimer disease: Paired helical filaments-like hyperphosphorylation of tau is a typical feature of AD, however, it also occurs under physiologically controlled conditions such as hibernation (Arendt et al., 2003; Härtig et al., 2007; Stieler et al., 2009, 2011; Avila et al., 2012; Bullmann et al., 2016).