EFFECTS OF DECEREBRATION ON BLOOD-PRESSURE DURING PARADOXICAL SLEEP IN CATS

We investigated the effects of decerebration on long-term variations i n arterial blood pressure during paradoxical sleep (PS) in cats, In no rmal cats, the blood pressure decreased during the transition from slo w wave sleep to PS and maintained its lower level throughout PS for se veral days after surgery, After this early postoperative stage, howeve r, the arterial hypotension was replaced by tonic and phasic rises in blood pressure during PS, Such long-term changes in blood pressure wer e completely abolished when the brain stem was transected at the ponto -mesencephalic junction, and the cats consistently exhibited a sustain ed fall in blood pressure throughout the survival periods of 1 month o r more.