Effect of decerebration on blood pressure during paradoxical sleep in cats.

We investigated the effects of decerebration on long-term variations in arterial blood pressure during paradoxical sleep (PS) in cats. In normal cats, the blood pressure decreased during the transition from slow wave sleep to PS and maintained its lower level throughout PS for several days after surgery. After this early postoperative stage, however, the arterial hypotension was replaced by tonic and phasic rises in blood pressure during PS. Such long-term changes in blood pressure were completely abolished when the brain stem was transected at the ponto-mesencephalic junction, and the cats consistently exhibited a sustained fall in blood pressure throughout the survival periods of 1 month or more.