HDAC6 and Alzheimer disease: Therefore, we analyzed in sedentary and exercised SAMP8 and SAMR1 mice, the hippocampal expression of the HAT P300 and the NAD+ dependent HDAC Sirt1, both of which have been implicated in AD pathogenesis (Pallas et al., 2008b; Min et al., 2010) as well as a group of NAD+ independent HDACs (Hdac1, Hdac2, Hdac3, Hdac5, Hdac6).