Periodic breathing: How does it happen and does it cause sleep disruption in hypoxia?

REM sleep disruption and periodic breathing are common in hypoxic environments, such as at altitude (7). Periodic breathing does not occur often in intact unanesthetized cats as a hypoxic ventilatory response, but occurs frequently as a post-hypoxic response (3, 5). Our recordings of medullary respiratory neurons and diaphragmatic activity indicate that periodic breathing results from central changes in levels of phasic and tonic respiratory output. Experimental studies in cat indicate that hypocapnia causes REM sleep disruption and therefore that it, rather than hypoxia, may be responsible for the sleep disruption at altitude.