Microwave amplitude reflecting instability of LFP electrode ground field is useful for consciousness state identification

We recently developed original electroencephalogram indices focusing on microwaves of flattish period (named $\tau$), which correlated with volatile anesthesia concentration in dogs. However, this mechanism remains unclear. $\tau$ was defined as a subthreshold wave and burst wave was defined as an above-threshold wave. This study shows that these indices well quantified the morphological features of local field potential waveforms in mice, and made it possible to discriminate the specific waveforms of the state of consciousness; awake, shallow sleep, rapid eye movement sleep, and non-rapid eye movement sleep. In addition, examination of $\tau$ suggested that microwaves are local fluctuations of the electrode that can be formed for each data sampling, and that its amplitude may increase with the degree of arousal.