Figure 4. Optogenetic inhibition of VTA_Gad67+ neurons induced wakefulness even under conditions of high homeostatic sleep pressure.

(a) Schematic of the protocol of the experiment. (b) EEG, EEG power spectra, and EMG before and after optogenetic inhibition during recovery sleep after 4 hr sleep deprivation. (c) Summary of the experiment in (a) showing the probability of each vigilance state before and after blue light illumination. Colored circles and lines indicate mean probability of each vigilance state and shaded area indicates SEM (ACR2-2A-mCherry: n = 6 mice and mCherry alone: n = 5 mice).