Fig. 5. Excitation of GABAergic neurons in the VTA induces sleep and their inhibition produces continuous wakefulness.

(a) Excitation and inhibition of VTA^Vgat neurons. AAV-DIO-hM3Dq-mCherry or AAV-DIO-hM4D_i-mCherry was injected into the VTA of Vgat-ires-Cre mice. Images show the expression of hM3Dq-mCherry or hM4D_i-mCherry in the VTA. The experiment was repeated independently 6 times. IF, interfasicular nucleus; PBP, parabrachial pigmented nucleus; PN, paranigral nucleus; PBP, parabrachial pigmented nucleus; RLi, rostral linear nucleus;

(b) Excitation of VTA^Vgat neurons induces NREM sleep and suppresses REM sleep. Two individual EEG/EMG spectra and extracted delta power from the EEG are shown for VTA^Vgat-hM3Dq mice that received saline (n=7 mice) or CNO (n=7 mice) i.p. injection during wake period (“lights off” period). The percentage and time in wake, NREM and REM sleep after saline (n=7 mice) or CNO (n=7 mice) injection are shown. “Epoch” indicates vigilance state: blue, wake; green, NREM sleep; magenta, REM sleep.

(c) Excitation of VTA^Vgat neurons reduces latency to NREM sleep. Latencies to NREM and REM sleep after saline (n=7 mice) or CNO (n=7 mice) i.p. injection into VTA^Vgat-hM3Dq mice.

(d) Inhibition of VTA^Vgat neurons induces wakefulness. Two individual EEG/EMG spectra and extracted delta power from the EEG are shown for VTA^Vgat-hM4D_i mice that received saline (n=7 mice) or CNO (n=7 mice) i.p. injection at the start of sleep period (“lights on” period). The percentage and time in wake, NREM and REM sleep after saline (n=7 mice) or CNO (n=7 mice) i.p. injection are shown. “Epoch” indicates vigilance state: blue, wake; green, NREM sleep; magenta, REM sleep.

(e) Inhibition of VTA^Vgat neurons increases latency to sleep. Latencies to NREM (n=7 mice) and REM sleep (n=7 mice) after CNO or saline i.p. injection into VTA^Vgat-hM4D_i mice.

*p<0.05, **p<0.01, ****p<0.0001; two-sided unpaired t-test. All error bars represent the SEM. For detailed statistics information, see Supplementary Table1.