MAPT and Alzheimer disease: Indeed, this model may be useful to study the neuroprotection mechanisms in the first stages of neurodegenerative disorders such as Alzheimer's disease (AD), since neurons from hibernating animals show a transitory PHF (Paired Helical Filaments)-like tau phosphorylation with some similarities to that of patients at early stages of the disease (Zhou et al., 2001; Arendt et al., 2003; Avila et al., 2004; Härtig et al., 2005, 2007; Su et al., 2008; Stieler et al., 2011; León-Espinosa et al., 2013).