Multichannel EEG analysis of respiratory evoked potential components during wakefulness and NREM sleep

Airway occlusion in awake humans produces a somatosensory evoked response called the respiratory-related evoked potential (RREP). In the present study, 29 channel evoked-potential recordings were obtained from seven men who were exposed to 250-ms inspiratory airway occlusions during wakefulness, stage 1, stage 2, and slow-wave sleep. The RREP recorded during wakefulness was similar to previous reports, with the unique observation of an additional short-latency positive peak with a mean latency of 25 ms. Short-latency RREP components were maintained in nonrapid-eye-movement (NREM) sleep. The clearly seen N-1 vertex and late positive complex components during wakefulness were markedly attenuated during NREM sleep, and two large negative components (N-300 and N-550) dominated the sleep RREP. These findings indicate the maintenance of central nervous system monitoring of respiratory afferent information during NREM sleep, presumably to facilitate protective arousal responses to pathophysiological respiratory phenomena.