Abstract
Tilia extracts have been used for centuries for their relaxing and hypnotic properties; however, their impact on the sleep-wake cycle and sleep architecture remained elusive. In this study, we investigated the effects of a chronic treatment with Tilia tomentosa extracts on the sleep-wake cycle and the associated neuronal activity, using chronic electrophysiological recordings in freely moving mice. We found that Tilia treatment induced a significant increase in NREM sleep and a concomitant reduction of wakefulness during the nocturnal (active) hours, in treated mice compared to controls. Furthermore, the treatment significantly reduced brief awakenings during light (resting) hours. Tilia did not cause alterations of the essential electrophysiological features of the EEG signal. Moreover, Tilia administration did not impair either the homeostasis or the structure of the sleep-wake cycle. Spectral analysis reported mild changes in high gamma and theta bands in Tilia-treated mice compared to controls. Altogether, our data provide preliminary evidence that Tilia favours sleep and reduces sleep fragmentation, without interfering with the physiological structure of sleep and the associated neuronal activity.