Interactive effects of apneic and baroreflex stress on neuronal coding strategies in human muscle sympathetic nerve activity

Abstract

Discrete physiological stressors differentially affect sympathetic postganglionic neuronal rate-, population-, and temporal-coding strategies. When performing end-expiratory apnea (APN) during graded baroreflex unloading via lower body negative pressure (LBNP): 1) augmented sympathetic neuronal firing probability, 2) recruited larger and previously silent sympathetic postganglionic neurons at ambient and −10 mmHg, but not −40 mmHg LBNP, and 3) reduced neuronal discharge latency similarly across all conditions, independent of the level of baroreflex unloading.