EN
Sleep-wake cycle, a dynamic process of alternating states of vigilance, is usually described by means of quantitative methods. In our EEG study performed on WAG/Rij rats, a validated, genetic animal model of absence epilepsy, correlation and cross-correlation functions over time were applied on 24 h data collected in 12:12 light-dark cycle in order to investigate temporal coupling between absence seizures and sleep-wake states, and between sleep-wake states themselves. We found significant light/ dark-related differences in temporal organization: first, absence seizures showed bidirectional coupling with sleep-wake states in the dark phase only. Second, temporal relationships among states of vigilance followed phase-related alterations, which were the most prominent at the light onset. These results were confirmed in a non-epileptic control strain. Our approach suggests that different processes are governing sleep and wake in the light and dark period.