Plasticity of respiratory rhythm-generating mechanisms in adult goats.
Abrupt destruction of >70% of the pre-Bötzinger complex (preBötzC) in awake goats results in terminal apnea (Wenninger et al. 2004b). Herein we report data on awake and sleeping goats in which the preBötzC was incrementally destroyed by injection of ibotenic acid (IBO) in increasing volumes at weekly intervals. All injections resulted in an acute tachypnea and dysrhythmia featuring apneas and increased variation in breathing. In studies at night, 10-15 hours after the injections, apneas were nearly all central and occurred during the awake state and variation in breathing was greater while awake than during NREM sleep. However, one week after the final IBO injection, the breathing pattern, breath-to-breath variation, and arterial blood gases were unchanged from baseline, indicating recovery. Histology revealed more than 90% destruction of the preBötzC region, and greater than 80% destruction of the surrounding area. We conclude: (1) the dysrhythmic effects on breathing acutely after the injection are state-dependent, and (2) after incremental, near-complete destruction of the preBötzC region, time-dependent plasticity within the respiratory network provides a normal respiratory rhythm that sustains normal arterial blood gases.
Forster
Hubert V
HV
Department of Physiology, Medical College of Wisconsin, Milwaukee, WI, USA. bforster@mcw.edu
Krause
Katie L
KL
Kiner
Tom
T
Neumueller
Suzanne E
SE
Bonis
Josh M
JM
Qian
Baogang
B
Pan
Lawrence G
LG
D000818:Animals; D001158:Arteries; D001784:Blood Gas Analysis; D006041:Goats; D007051:Ibotenic Acid / Q000494:pharmacology; D009473:Neuronal Plasticity / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D010507:Periodicity; D018040:Receptors, Neurokinin-1 / Q000378:metabolism; D015656:Respiratory Mechanics / Q000187:drug effects / Q000502:physiology*; D014851:Wakefulness / Q000502:physiology
D018040:Receptors, Neurokinin-1; D007051:Ibotenic Acid