Effects of intracerebroventricular injection of 0.6 nmol of UII on the EEG power. UII induced a significant increase in the mean power of θ (A; p < 0.01) and γ (B; p < 0.01) bands during W, as well as a significant increase in γ during REM sleep (D; p < 0.01) compared with saline, whereas UII reduced the δ power in SWS2. However, this reduction did not reach significant levels (C). These results confirm the role of UII in cortical activation. Bars represent mean values (±SEM; n = 6 rats per group). Significant effects of UII compared with the saline group were identified using a t test and are indicated by asterisks.