Figure 2.

Changes in sleep-wake stages after Hcrt-1 administration. a: Polygraphic sleep-wake data for the 4 h periods after Hcrt-1 (3 µg/kg) in comparison to the same periods after normal saline shows a significant decrease in REM sleep. b: Sleep-wake actigraph data show a significant increase in sleep bout duration and a decrease in frequency during the dark period after Hcrt-1. c: Changes in wake bout duration and frequency (in 24-hour period). Pre=saline control before Hcrt-1; AW=active wake; QW=quite wake; nonREM=non-rapid eye movement sleep; REM=rapid eye movement sleep. All values are mean ±SE; †p<0.05 compared to saline control, t-test; *p<0.05, **p<0.01, compared to pre-treatment level, Newman-Keuls test.