Figure 2.

Activation of basal forebrain (BF) cholinergic neurons inhibited electroencephalogram power spectrum. (a, b) Example hypnogram, fast Fourier transform-derived delta and theta power, and electromyogram activity following administration of vehicle (a) or 1 mg/kg clozapine-N-oxide (CNO) (b) in a ChAT-IRES-Cre mouse with bilateral hM3Dq receptors expression in BF cholinergic neurons. Black=wakefulness (W), pink=REM sleep (R), blue=normal-delta NREM sleep (N), and gray=CNO-induced low-delta state (LS). (c) Time course changes of delta, theta, alpha, and beta power over baseline after injections of different doses of CNO (n=7–10). ^*P<0.05, ^**P<0.01 vs vehicle, as assessed by repeated-measures ANOVA followed by probable least-squares difference (PLSD) test. (d) Quantitative changes of delta, theta alpha, and beta power over baseline during the 8 h period after injection (0900–1700, n=8–10). The value of power spectrum after vehicle injection was defined as baseline. Vehicle group and CNO group mice were injected with vehicle and CNO, respectively, on the experimental day. The data were standardized and expressed as percentages of the baseline. ^*P<0.05, ^**P<0.01 vs vehicle; ^#P<0.05, ^##P<0.01 vs CNO 0.1 mg/kg; ^&P<0.05, ^&&P<0.01 vs CNO 0.3 mg/kg, assessed by one-way ANOVA followed by the PLSD test.