A large scale, high resolution, automated system for rat sleep staging. II. Validation and application.

An automated rat sleep staging system was used to describe sleep-waking behaviour in a large number of rats. The computer scorings were validated by visual analysis of a limited set of data by two human raters and the agreement varied between 82 and 100% for homogeneous segments of the different sleep-waking stages. The automated system proved to be very consistent in view of the small variation in placebo values over 110 experiments. The data show that classification of rat sleep waking behaviour into 6 different stages is both advisable and feasible. The experiments further show that rat age (over a range from 0.5 to 2 years) does not greatly affect rat sleep-waking behaviour.