Fig. 4. Rapid eye movement (REM) sleep at baseline and after deprivation. REM sleep was scored in 30-s epochs, collected in 6-h blocks, and expressed as mean number of epochs/time block ± SD. Note that REM behavior was not plotted for propofol rats during anesthesia. Shaded areas depict dark phase (6:00 PM–6:00 AM) recording. *, †P < 0.05 when compared with baseline values for propofol and intralipid groups, respectively. AM and PM are denoted as a and p , respectively.