Analysis of the Vigilance Stages in the Rat by Fast Fourier Transformation

Abstract

The characteristics of the power density spectra of the frontal and occipital cortical EEG between 1 and 31 Hz as well as the total power of the neck muscle EMG during an 8-second epoch were used to differentiate 8 vigilance stages in normal rats. The following stages and the time spent within these stages during a 6-hour recording (9.00–15.00) were evaluated: waking with active EMG (about 127 min), waking (7 ± 3 min), theta-waking (25.5 ± 9 min), classical sleep I (dozing; 107 ± 11 min), classical sleep II (41 ± 6 min), paradoxical sleep (PS; 30 ± 9 min), transitional phase (PS spindles; 9.5 ± 4 min) and transitional dozing (13 ± 3 min). Two additional stages were differentiated in rats suffering from petit mal: paroxysmally occurring spikes and waves and an especially marked transitional phase. The absolute power spectra of these vigilance stages (except active waking) were plotted as well as the statistically analyzed deviations from the mean power spectra of all epochs without active EMG. A comparison between the mean power spectra of a control recording and a recording after oral application of 10 mg/kg diazepam indicates that these differences are less marked than between the vigilance stages.

Influence of zopiclone, a new generation hypnotic, on the intermediate stage and paradoxical sleep in the rat

“…They are of maximal amplitude prior to paradoxical sleep (PS) where they appear during a few seconds simultaneously with hippocampal low frequency theta rhythm. This pattern association, which was observed by several researchers (Gottesmann 1964;Weiss and Adey 1965;Depoortere and Loew 1973;Gaillard et al 1977;Trachsel et al 1988;Kleinlogel 1990;Neckelmann and Ursin 1993;Benington et al 1994), characterizes the intermediate stage of sleep (IS, Fig. 1) (Gottesmann 1996).…”

Sequential Neural Activity in Primary Motor Cortex during Sleep

“…Conventionally, human sleep periods have been separated into different phases by visual examination of the EEG (Berry et al, 2015). Different sleep phases are associated with relative increases or decreases in power at different frequency bands of the EEG and/or LFP (Iber et al, 2007; Destexhe et al, 1999), but there is no consensus on the number of identifiable discrete sleep states in animals (Kleinlogel, 1990; Gottesmann, 1992). To provide a simple and consistent characterization of the sleep cycle, we used the periodic fluctuations in the power of low-frequency (<1 Hz) LFPs (Achermann and Borbély, 1997; Steriade et al, 1993a,b; Destexhe et al, 1999) to derive a continuous measure of sleep phase (Fig.…”

The intermediate stage and paradoxical sleep in the rat: influence of three generations of hypnotics

“…These spindles progressively increase in number and amplitude ( Gottesmann 1972;Terrier & Gottesmann 1978;Bjorvatn et al 1995 ). They reach their maximal amplitude and duration just prior to paradoxical sleep (PS) and are associated with hippocampal low‐frequency theta rhythm ( Gottesmann 1964;Weiss & Adey 1965;Depoortere & Loew 1973;Gaillard et al 1977 ;Trachsel et al 1988 ;Kleinlogen 1990;Neckelmann & Ursin 1993;Benington et al . 1994 ;Lancel et al 1996b ).…”