Neural Drives and Breathing Stability

Cessation of breathing and cyclic variations in tidal volume and frequency are far more likely to be precipitated when hypoxia or transient hyperventilation produces subnormal levels of PCO2 in NREM sleep and at sleep onset, than in awake subjects. The ability of the awake subject to breathe with only rare apneas and oscillations in ventilation at levels of PCO2 considerably below resting seems to depend on the interplay of chemical and neural drives.