Modulation of Respiration by Brain Hypoxia
The dual nature of hypoxic modulation of central respiratory activity is best appreciated in the sino-aortic deafferented, anesthetized animal during progressive reductions in the arterial oxygen content.1 Figure 1 illustrates these two distinct central respiratory responses to brain hypoxia and their different oxygen thresholds; respiratory depression, which is manifested with even modest reductions in oxygenation, and respiratory excitation (gasping), which occurs only with severe reductions in the arterial oxygen content (to values less than 20%).
KeywordsPhrenic Nerve Severe Hypoxia Brain Hypoxia Neuronal Excitation Carotid Sinus Nerve
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- 2.Q.P. Yu, J.E. Melton, J.K-J. Li, J. A. Neubauer, and N.H. Edelman, The response of the phrenic neurogram to sinusoidal brain hypoxia, FASEB Journal 5:A665 (1991).Google Scholar
- 4.J.E. Melton, Q.P. Yu, J.A. Neubauer, and N.H. Edelman, Effect of brain hypoxia on peripheral chemoreception and respiratory afterdischarge in the cat, J. Appl. Physiol. (in press).Google Scholar
- 14.F.P. Nissley, J.E. Melton, J.A. Neubauer, and N.H. Edelman, Effect of adenosine antagonism on phrenic nerve output during brain hypoxia, Fed. Proc. 45:1046 (1986).Google Scholar
- 17.L. Oyer-Chae, J.E. Melton, J.A. Neubauer, and N.H. Edelman, Differential phrenic (PN) and sympathetic nerve responses to an NMDA blocker in progressive brain hypoxia (PBH). FASEB Journal 4:A405 (1990).Google Scholar
- 18.L. Oyer-Chae, J.E. Melton, J.A. Neubauer, and N.H. Edelman, Non-NMDA blockade alters eupneic but not hypoxia-induced gasping activity of the phrenic nerve, FASEB Journal 5: A664 (1991).Google Scholar