Elicitation of theoretically predicated feedback oscillation in arterial pressure.

Abstract

In a preceding servoanalytic study of the cerebral ischemic pressor response, the authors predicted that, under certain conditions, this emergency mechanism would go into a feedback oscillation and vasomotor waves would appear. The predicted conditions were a) that the cerebral perfusion pressure be as low as 30–10 mm Hg and b) that the time-dependent variable components of the systemic arterial pressure be transferred to the perfusion pressure with the same magnitude. The present experiment was conducted for the purpose of confirming such a theoretical prediction. The transfer of the systemic arterial pressure changes to the cerebral perfusion pressure was accomplished by a special coupling apparatus, and in all of the 11 experiments the cerebral ischemic response mechanism lapsed into feedback oscillation, and intense vasomotor waves were brought about. The period of these waves coincided almost exactly with those predicted by the servoanalysis of the cerebral ischemic response in individual dogs.