Fig. 6
NAc D1R neurons control arousal through midbrain and LH pathways. a, g Schematic diagram showing the location of the optic fiber in the midbrain (a) or LH (g), and the implanted somnographic electrodes of a D1R-Cre mouse injected with AAV-ChR2-mCherry in the NAc. b, h Sections stained for mCherry showing ChR2-mCherry-positive terminals in the midbrain (b) or LH (h), and the cannula trace showing the optic fibers targeting the nuclei. Scale bars: 200 μm; f fornix. c, i Representative EEG and EMG traces and the corresponding heat map of EEG power spectrum showing that photostimulation in the midbrain (c) or LH (i) applied during NREM sleep induced a rapid transition to wakefulness. Dashed lines indicate onset of light stimulation. d, j Representative EEG and EMG recordings and the corresponding heat map of EEG power spectrum showing that yellow light stimulation in the midbrain (d) or LH (j) failed to affect the sleep–wake pattern. Scale bars: 8 s. e Mean latencies of wake transitions during NREM sleep after acute photostimulation at different frequencies (n = 5, paired t test; Base, t4 = 0.4, P = 0.7; 5 Hz, t4 = 2.4, P = 0.08; 20 Hz, t4 = 28.5, P = 9 × 10−6; 50 Hz, t4 = 81.8, P = 1.3 × 10−7). Data analysis was based on an average of 8–12 stimulations per frequency and per mouse. f Total amounts of each stage in the control and 20 Hz photostimulation in the midbrain during 09:00–10:00 (n = 5, paired t test; t4 = 9.5, P = 7 × 10−4 (wake); t4 = 9.4, P = 7 × 10−4 (NREM); t4 = 3.8, P = 0.02 (REM)). k Mean latencies of wake transitions during NREM sleep after photostimulation at different frequencies (n = 5, paired t test). Data analysis was based on an average of 8–12 stimulations per frequency and per mouse. l Total amounts of each stage in the control and 20 Hz photostimulation in the LH during 09:00–10:00 (n = 6, paired t test). Data represent mean ± s.e.m. *P < 0.05, **P < 0.01
