Fig. 4.

Delta power changes induced by modafinil during non-rapid eye movement sleep (NREMS) in R6/2 and wild-type mice. Delta power (1–4 Hz) was averaged for each hour after the injection of vehicle or modafinil (100 mg/kg, i.p.) at the beginning of active phase in wild-type (WT, a) or in R6/2 mice aged 12 weeks (b) and 16 weeks (c). Note that due to the robust NREMS-decreasing effect of modafinil (1–7 h) in WT and in R6/2 mice at 12 weeks of age (d and e, respectively), as well as (1–5 h) at 16 weeks of age (f), the average delta power data for these hours were not evaluated statistically. The vertical dashed lines show the end of the wake-promoting effect in each group. The arrows show the beginning of the ‘delta rebound’. Data are presented as mean ± SEM. *p < 0.05, compared to the relevant vehicle group