[Changes in the correlations between the cortical and subcortical brain structures of rats during a shift in the sleep phases].

Studies have been made on the role of correlational relationships between EEG parameters of the brain structures in mechanisms of changes in sleep phases in Wistar rats. Spectral and correlative analysis of the EEG in the visual and sensory-motor cortex, hippocamp and nucleus caudatus was made. The data obtained revealed differences between EEG parameters during sleep--wakefulness cycle. Paradoxical sleep phase differed from slow-sleep phase by weak correlation (+0.39 +/- 0.04) between the visual cortex and subcortical structures. On the contrary, only strong correlation was observed during slow-sleep (+0.73 +/- 0.07) between these structures. During wakefulness, correlation was equal to +0.56 +/- 0.05.