Optimized single electroencephalogram channel sleep staging in rats

Most studies of sleep staging in rats use both multichannels electroencephalogram (EEG) and electromyogram (EMG), so it would be convenient and meaningful in some fields if sleep staging in rats could be realized using a single EEG channel. In this study, we used a single bipolar cortical EEG electrode at the frontal-parietal location with a 0.5-30 Hz filter band and a clustering sleep-staging algorithm including seven classification parameters. The agreements between the computer and two independent raters were 96.9 ± 1.1% for Wake, 97.1 ± 1.4% for non-rapid eye movement (NREM) sleep, and 91.4 ± 2.5% for rapid eye movement (REM) sleep, and the overall agreement was 96.7 ± 0.7%. These results indicate that the accuracies of sleep staging remain high even though only a single EEG channel was used and that a system based on this scheme would be suitable for realtime and long-term studies of sleep.