Some aspects of the polygraphic studies on sleep-wakefulness cycle in rat.

The various phases characterizing the sleep-wakefulness cycle were studied in rats. Electroencephalographic and electromyographic results were both analysed using classical visual methods and more sophisticated techniques such as spectral analysis and Hjorth parameters. The latter approach was very useful in obtaining a rapid characterization of regional and general brain activity and is applicable to the study of the EEG and EMG profiles of different pharmacological agents. Together with the conventional studies on the sleep-wakefulness cycle, the methodology reported here gives a powerful battery for the study of new centrally acting drugs.