Journal of Applied Physiology, Vol 73, Issue 5 1958-1971, Copyright © 1992 by American Physiological Society

ARTICLES

Determinants of poststimulus potentiation in humans during NREM sleep

M. S. Badr, J. B. Skatrud and J. A. Dempsey
Medical Service, William S. Middleton Memorial Veterans Hospital, Madison, Wisconsin.

To test whether active hyperventilation activates the "afterdischarge" mechanism during non-rapid-eye-movement (NREM) sleep, we investigated the effect of abrupt termination of active hypoxia-induced hyperventilation in normal subjects during NREM sleep. Hypoxia was induced for 15 s, 30 s, 1 min, and 5 min. The last two durations were studied under both isocapnic and hypocapnic conditions. Hypoxia was abruptly terminated with 100% inspiratory O2 fraction. Several room air-to-hyperoxia transitions were performed to establish a control period for hyperoxia after hypoxia transitions. Transient hyperoxia alone was associated with decreased expired ventilation (VE) to 90 +/- 7% of room air. Hyperoxic termination of 1 min of isocapnic hypoxia [end-tidal PO2 (PETO2) 63 +/- 3 Torr] was associated with VE persistently above the hyperoxic control for four to six breaths. In contrast, termination of 30 s or 1 min of hypocapnic hypoxia [PETO2 49 +/- 3 and 48 +/- 2 Torr, respectively; end-tidal PCO2 (PETCO2) decreased by 2.5 or 3.8 Torr, respectively] resulted in hypoventilation for 45 s and prolongation of expiratory duration (TE) for 18 s. Termination of 5 min of isocapnic hypoxia (PETO2 63 +/- 3 Torr) was associated with central apnea (longest TE 200% of room air); VE remained below the hyperoxic control for 49 s. Termination of 5 min of hypocapnic hypoxia (PETO2 64 +/- 4 Torr, PETCO2 decreased by 2.6 Torr) was also associated with central apnea (longest TE 500% of room air). VE remained below the hyperoxic control for 88 s. We conclude that 1) poststimulus hyperpnea occurs in NREM sleep as long as hypoxia is brief and arterial PCO2 is maintained, suggesting the activation of the afterdischarge mechanism; 2) transient hypocapnia overrides the potentiating effects of afterdischarge, resulting in hypoventilation; and 3) sustained hypoxia abolishes the potentiating effects of after-discharge, resulting in central apnea. These data suggest that the inhibitory effects of sustained hypoxia and hypocapnia may interact to cause periodic breathing.

This article has been cited by other articles:

				S. Ryan and P. Nolan Episodic hypoxia induces long-term facilitation of upper airway muscle activity in spontaneously breathing anaesthetized rats J. Physiol., July 1, 2009; 587(13): 3329 - 3342. [Abstract] [Full Text] [PDF]

				T. A. Day and R. J. A. Wilson Specific carotid body chemostimulation is sufficient to elicit phrenic poststimulus frequency decline in a novel in situ dual-perfused rat preparation Am J Physiol Regulatory Integrative Comp Physiol, August 1, 2005; 289(2): R532 - R544. [Abstract] [Full Text] [PDF]

				J. H Mateika, Q. Omran, J. A Rowley, X. S Zhou, M. P Diamond, and M. S. Badr Treatment with leuprolide acetate decreases the threshold of the ventilatory response to carbon dioxide in healthy males J. Physiol., December 1, 2004; 561(2): 637 - 646. [Abstract] [Full Text] [PDF]

				A. M. Omran, S. E. Aboubakr, L. S. Aboussouan, L. Pierchala, and M. S. Badr Posthypoxic ventilatory decline during NREM sleep: influence of sleep apnea J Appl Physiol, June 1, 2004; 96(6): 2220 - 2225. [Abstract] [Full Text] [PDF]

				I. Mitrouska, E. Kondili, G. Prinianakis, N. Siafakas, and D. Georgopoulos Effects of Theophylline on Ventilatory Poststimulus Potentiation in Patients with Brain Damage Am. J. Respir. Crit. Care Med., April 15, 2003; 167(8): 1124 - 1130. [Abstract] [Full Text] [PDF]

				B. F. BuSha and M. H. Stella State and chemical drive modulate respiratory variability J Appl Physiol, August 1, 2002; 93(2): 685 - 696. [Abstract] [Full Text] [PDF]

				M. Shkoukani, M. A. Babcock, and M. S. Badr Effect of episodic hypoxia on upper airway mechanics in humans during NREM sleep J Appl Physiol, June 1, 2002; 92(6): 2565 - 2570. [Abstract] [Full Text] [PDF]

				F. Han, S. Subramanian, E. R. Price, J. Nadeau, and K. P. Strohl Periodic breathing in the mouse J Appl Physiol, March 1, 2002; 92(3): 1133 - 1140. [Abstract] [Full Text] [PDF]

				F. Han, S. Subramanian, T. E. Dick, I. A. Dreshaj, and K. P. Strohl Ventilatory behavior after hypoxia in C57BL/6J and A/J mice J Appl Physiol, November 1, 2001; 91(5): 1962 - 1970. [Abstract] [Full Text] [PDF]

				A. Xie, J. B Skatrud, and J. A Dempsey Effect of hypoxia on the hypopnoeic and apnoeic threshold for CO2 in sleeping humans J. Physiol., August 15, 2001; 535(1): 269 - 278. [Abstract] [Full Text] [PDF]

				A. Xie, J. B. Skatrud, D. C. Crabtree, D. S. Puleo, B. M. Goodman, and B. J. Morgan Neurocirculatory consequences of intermittent asphyxia in humans J Appl Physiol, October 1, 2000; 89(4): 1333 - 1339. [Abstract] [Full Text] [PDF]

				A. K. Curran, J. R. Rodman, P. R. Eastwood, K. S. Henderson, J. A. Dempsey, and C. A. Smith Ventilatory responses to specific CNS hypoxia in sleeping dogs J Appl Physiol, May 1, 2000; 88(5): 1840 - 1852. [Abstract] [Full Text] [PDF]

				A. S. Jordan, P. G. Catcheside, R. S. Orr, F. J. O'Donoghue, N. A. Saunders, and R. D. McEvoy Ventilatory decline after hypoxia and hypercapnia is not different between healthy young men and women J Appl Physiol, January 1, 2000; 88(1): 3 - 9. [Abstract] [Full Text] [PDF]

				A. A. Menendez, T. J. Nuckton, J. E. Torres, and D. Gozal Short-term potentiation of ventilation after different levels of hypoxia J Appl Physiol, May 1, 1999; 86(5): 1478 - 1482. [Abstract] [Full Text] [PDF]

				A. JUBRAN, B. J. B. GRANT, and M. J. TOBIN Effect of Hyperoxic Hypercapnia on Variational Activity of Breathing Am. J. Respir. Crit. Care Med., October 1, 1997; 156(4): 1129 - 1139. [Abstract] [Full Text] [PDF]

				D. Sajkov, A. Neill, N. A. Saunders, and R. D. McEvoy Comparison of effects of sustained isocapnic hypoxia on ventilation in men and women J Appl Physiol, August 1, 1997; 83(2): 599 - 607. [Abstract] [Full Text] [PDF]