Sleep and EEG disturbances in a rat neurological mutant (taiep) with immobility episodes: a model of narcolepsy-cataplexy.

The electroencephalographic sleep patterns recorded during short periods of time (3 h) of a neurological mutant rat (taiep) were studied. This rat exhibits, among other signs, immobility episodes that are similar to those observed in narcolepsy-cataplexy. We describe findings of long term (6 months) electroencephalographic studies done in 9 mutant and 5 control rats. The mutant rats present electroencephalographic and behavioral disorders consisting of: (a) bursts of cortical waxing and waning waves occurring during the drowsy state; in some animals this activity represents up to 25% of the total drowsiness time; (b) shortened sleep time; (c) fragmented paradoxical sleep; (d) immobility episodes when the animals are subjected to an emotional excitement; and (e) electrographic activity of paradoxical sleep without atonia during the immobility episodes. These findings show that the taiep mutant shows several aspects of narcolepsy-cataplexy and it may represent an experimental model for the study of this pathology.