Fig. 3

Optogenetic activation of the SCN-HDB pathway promotes NREM sleep during the dark phase. A and D An example trial of one of the optogenetic experiments. Shown are the EEG power spectrum, EEG traces and EMG trace of 900 s. The black bar represents the dark phase. The blue bar represents the period of laser stimulation (Left:10 ms per pulses, 5 Hz, 300 s; Right:10 ms per pulses, 20 Hz, 300 s). B and E Propotion of wake, NREM sleep, and REM sleep states before, during, and after 5–20 Hz laser stimulation during the dark phases. Blue shading indicates pulse laser stimulation of 300 s. C and F 5–20 Hz laser-induced change in the proportion of each states in AAV-ChR2-treated and AAV-eGFP-treated mice (N = 8 mice for 5 Hz, N = 7 mice for 20 Hz, One way ANOVA. Error bars represent ± s.e.m.) W means Wake; S means NREM sleep; R means REM sleep. The data in here came from 8 mice or 7 mice injected with control virus or ChR2 virus, and each data indicated the proportion of Wake, NREM and REM during the 300s period given 5–20 Hz blue light pulse stimulation