Optimized single electroencephalogram channel sleep staging in rats

Abstract

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.

Gad1 knock-out rats exhibit abundant spike-wave discharges in EEG, exacerbated with valproate treatment

“…EEG patterns in Gad1 (–/–) rats during the awake or sleep (rapid eye movement and non-rapid eye movement) states appeared to be similar to those in normal animals ( 32 ) ( Figure 1A ). However, on visual inspection of the EEG data, frequent large-amplitude spiky waveforms caught the attention ( Figure 1A , SWD), which lasted a few seconds and oscillated at approximately 8 Hz ( Figure 1B ).…”

“…For fluorescent nucleus staining, we used a CellStain−4′,6-diamidino-2-phenylindol (DAPI) solution (1:500 dilution, Dojindo Kumamoto, Mashiki, Japan). Fluorescence images were acquired using an LSM 780 laser confocal microscope (Zeiss, Oberkochen, Germany) and a 63 × oil objective lens (numerical aperture: 1.4) and analyzed using the ZEN confocal image analysis software (Zeiss) and ImageJ software (National Institutes of Health, Bethesda, MD, USA), respectively ( 32 – 34 ) ( Supplementary Figures S1 , S2 ).…”