Fig. 1

Impaired NREM sleep, decreased delta power, and increased sleep fragmentation in APP mice at 6 months of age. (A) Left, diagram showing viral injection strategy to target GABAergic neurons with mCherry or ChR2-mCherry. Right, representative photomicrograph showing GABAergic neurons expressing ChR2-mCherry with DAPI (Gray). The dashed line shows the approximate location of the cannula track. Scale bar, 1 mm. (B) Left, diagram showing placement of EEG/EMG implant. Right, placement of EEG, EMG electrodes, and fiber-optic cannula on the skull. EMG electrodes were placed within the nuchal musculature. (C) Representative EEG and EMG traces during NREM, REM and wake states. (D and E) Overall 24-hour sleep pattern and sleep architecture of the NTG (D) and APP (E) mice. (F) Averaged time spent in each sleep-wake cycle stage (NREM, REM and wake) during 24-hour, 12-hour dark phase and 12-hour light phase of NTG and APP mice. (G) Time course of the changes in NREM sleep in NTG and APP mice. (H-J) Relative power spectral density of NREM sleep during 24-hour, 12-hour llight phase and 12-hour dark phase of NTG and APP mice. (K) The average EEG power density in the delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–12 Hz), sigma (12–16 Hz) and beta (16–24 Hz) bands during NREM sleep during 24-hour, 12-hour light phase and 12-hour dark phase of NTG and APP mice. (L and M) Average length (L) and bouts count (M) in each sleep-wake cycle stage (NREM, REM and wake) during 24-hour, 12-hour dark phase and 12-hour light phase of NTG and APP mice. All data are expressed as means ± standard error. The number of mice examined: NTG = 11 mice; APP = 12 mice. *P < 0.05, **P < 0.01, and ***P < 0.001. n.s. not significant