Accumulating evidences have revealed that neuronal oscillations with various frequency bands in the brain have different physiological functions. However, the frequency band divisions in rats were typically based on empirical spectral distribution from limited channels information. In the present study, functionally relevant frequency bands across vigilance states and brain regions were identified using factor analysis based on 9 channels EEG signals recorded from multiple brain areas in rats. We found that frequency band divisions varied both across vigilance states and brain regions. In particular, theta oscillations during REM sleep were subdivided into two bands, 5-7 and 8-11 Hz corresponding to the tonic and phasic stages, respectively. The spindle activities of SWS are different along the anterior-posterior axis, lower oscillations (~16 Hz) in frontal regions and higher in parietal (~21 Hz). The delta and theta activities were co-varied in the visual and auditory cortex during wakeful rest. In addition, power spectra of beta oscillations were significantly decreased in association cortex. These results provide us some new insights into understand the brain oscillations across vigilance states, and also indicate that the spatial factor should not be ignored when considering the frequency band divisions in rats.
Mozart's "Sonata for two pianos" (Köchel listing 448) has proven effective as music therapy for patients with epilepsy, but little is understood about the mechanism of which feature in it impacted therapeutic effect. This study explored whether tempo in that piece is important for its therapeutic effect. We measured the effects of tempo in Mozart's sonata on clinical and electroencephalographic parameters of 147 patients with epilepsy who listened to the music at slow, original, or accelerated speed. As a control, patients listened to Haydn's Symphony no. 94 at original speed. Listening to Mozart's piece at original speed significantly reduced the number of interictal epileptic discharges. It decreased beta power in the frontal, parietal, and occipital regions, suggesting increased auditory attention and reduced visual attention. It also decreased functional connectivity among frontal, parietal, temporal, and occipital brain regions, also suggesting increased auditory attention and reduced visual attention. No such effects were observed after patients listened to the slow or fast version of Mozart's piece, or to Haydn's symphony at normal speed. These results suggest that Mozart's "Sonata for two pianos" may exert therapeutic effects by regulating attention when played at its original tempo, but not slower or faster. These findings may help guide the design and optimization of music therapy against epilepsy.