Normal Breathing Pattern and Arterial Blood Gases in Awake and Sleeping Goats after Near Total Destruction of the Presumed Pre-Bötzinger Complex and the Surrounding Region

Authors

Katie L. Krause, Medical College of Wisconsin
Hubert Forster, Medical College of Wisconsin
T. Kiner, Medical College of Wisconsin
S. E. Davis, Medical College of WisconsinFollow
Joshua M. Bonis, Medical College of Wisconsin
B. Qian, Medical College of Wisconsin
Lawrence Pan, Marquette UniversityFollow

Document Type

Article

Language

eng

Format of Original

15 p.

Publication Date

2-1-2009

Publisher

American Physiological Society

Source Publication

Journal of Applied Physiology

Source ISSN

0021-8987

Original Item ID

doi: 10.1152/japplphysiol.90966.2008; PubMed Central: PMCID 2644246

Abstract

Abrupt neurotoxic destruction of >70% of the pre-Bötzinger complex (preBötzC) in awake goats results in respiratory and cardiac failure (Wenninger JM, Pan LG, Klum L, Leekley T, Bastastic J, Hodges MR, Feroah TR, Davis S, Forster HV. J Appl Physiol 97: 1629–1636, 2004). However, in reduced preparations, rhythmic respiratory activity has been found in other areas of the brain stem (Huang Q, St. John WM. J Appl Physiol 64: 1405–1411, 1988; Janczewski WA, Feldman JL. J Physiol 570: 407–420, 2006; Lieske SP, Thoby-Brisson M, Telgkamo P, Ramierz JM. Nature Neurosci 3: 600–607, 2000; St. John WM, Bledsoe TA. J Appl Physiol 59: 684–690, 1985); thus we hypothesized that, when the preBötzC is destroyed incrementally over weeks, time-dependent plasticity within the respiratory network will result in a respiratory rhythm capable of maintaining normal blood gases. Microtubules were bilaterally implanted into the presumed preBötzC of seven goats. After recovery from surgery, studies were completed to establish baseline values for respiratory parameters. At weekly intervals, increasing volumes (in order 0.5, 1, 5, and 10 μl) of ibotenic acid (IA; 50 mM) were then injected into the preBötzC. All IA injections resulted in an acute tachypnea and dysrhythmia featuring augmented breaths, apneas, and increased breath-to-breath variation in breathing. In studies at night, apneas were nearly all central and occurred in the awake state. Breath-to-breath variation in breathing was greater (P < 0.05) during wakefulness than during non-rapid eye movement sleep. However, one week after the final IA injection, the breathing pattern, breath-to-breath variation, and arterial blood gases and pH were unchanged from baseline, but there was a 20% decrease in respiratory frequency (f) and CO₂ sensitivity (P < 0.05), as well as a 40% decrease in the ventilatory response to hypoxia (P < 0.001). In subsequent histological analysis of the presumed preBötzC region of lesioned goats, it was determined that there was a 90 and 92% reduction from control goats in total and neurokinin-1 receptor neurons, respectively. Therefore, it was concluded that 1) the dysrhythmic effects on breathing are state dependent; and 2) after incremental, near total destruction of the presumed preBötzC region, time-dependent plasticity within the respiratory network provides a rhythm capable of sustaining normal arterial blood gases.

Comments

Accepted version. Journal of Applied Physiology, Vol. 106, No. 2 (February 1, 2009): 605-619. DOI. © 2009 The American Physiological Society. Used with permission.

Recommended Citation

Krause, Katie L.; Forster, Hubert; Kiner, T.; Davis, S. E.; Bonis, Joshua M.; Qian, B.; and Pan, Lawrence, "Normal Breathing Pattern and Arterial Blood Gases in Awake and Sleeping Goats after Near Total Destruction of the Presumed Pre-Bötzinger Complex and the Surrounding Region" (2009). Physical Therapy Faculty Research and Publications. 70.
https://epublications.marquette.edu/phys_therapy_fac/70