Two-month-old wild type (wt) (total mice = 22) and 5xFAD mice (total mice = 22) and 6-month-old 5xFAD mice (total mice = 8) were positioned on a time-controlled tilting platforms (Stuart Scientific Platform Rocker STR6) connected to a time relay (Mini Asymmetrical Cycle Timer, AC / DC 12-240V GRT8-S2, Regun) able to regulate their activation according to a pattern of 3 min OFF/10 s ON. The mice were divided into two groups: the first group (n = 11 for 2-months old and n = 4 for 6-months old mice) underwent sleep fragmentation for 30 days all day long (24 h), while the second one (n = 11 for 2-months old and n = 4 for 6-months old mice) was kept in cages under the same environmental conditions as fragmented mice, but in the absence of a time-controlled tilting platform, for the same length of time. In order to evaluate the effect of the protocol on sleep–wake cycle, an electroencephalography (EEG) and electromyographic (EMG) recording was performed on three animals per group (wild type n = 3 and 5xFAD n = 3) for 8 days (4 days in normal sleep conditions and 4 during sleep fragmentation). Only the EEG data from the last day were considered, as we preferred the day when the mouse was most likely to show adaptation to the chosen fragmentation system. Each recording was analyzed considering the 24-h day on the basis of the light/dark cycles imposed by the enclosure (8.00 a.m.–8.00 p.m.).
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