Fig. 1
From: The thalamic mGluR1-PLCβ4 pathway is critical in sleep architecture
Sleep patterns in wild-type (PLCβ4+/+) and phospholipase C β4-deficient (PLCβ4−/−) mice. a Representative electroencephalography (EEG) and electromyography (EMG) traces that were recorded during awake, nonrapid eye movement (NREM) sleep, and rapid eye movement (REM) sleep states in PLCβ4+/+ (traces at the i, ii, and iii sites in b) and PLCβ4−/− mice (traces at the iv, v, and vi sites in c). Low-amplitude and irregular EEG patterns with relatively high EMG signals characterize the awake state (i, iv). High-amplitude and slow EEG patterns with a reduction in EMG tone characterize NREM sleep (ii, v). Low-amplitude and regular EEG patterns in the θ-frequency range with EMG atonia are the typical features of REM sleep (iii, vi). b-c Representative hypnograms, fast Fourier transformation-derived delta (0.5–4 Hz) power, and EMG activity over 24 h in the PLCβ4+/+ and PLCβ4−/− mice. The y-axis of the hypnograms shows the state of vigilance, and the x-axis shows the 24-h period that included 1 light and 1 dark (gray bars) cycle. d The expanded hypnogram shows the spike-wave discharge (SWD) events (small vertical bars, green) that occurred for 1 h. The PLCβ4−/− mice exhibited spontaneous SWDs with reduced EMG tone in the awake state in the raw EEG and EMG traces. e The percentage of SWD duration occurring in the light and dark phases. SWDs were observed in all vigilance states, but few events were observed in each 12-h period. The data from the PLCβ4−/− mice (n = 9) are presented as mean ± standard error of the mean (SEM)