Responses of nucleus ambiguus neurons to arterial pressure manipulations.

Nearly 69% of nucleus ambiguus neurons in the anesthetized, artificially respired dog responded to nonpharmacological manipulations of arterial pressure (AP). All were active at resting AP, most responded robustly to increased AP, and of these, about half showed activity modulated by the respiratory cycle. Other AP-sensitive neurons fired only during the inspiratory or expiratory phase of the pump-driven respiratory cycle, and were inhibited by increased AP and excited by decreased AP.