The effects of lesions in the dorsolateral pons on the coordination of swallowing and breathing in awake goats. Respir Physiol Neurobiol 2011 Feb 15;175(2):272-82 PMID: 21145433 PMCID: PMC3033492
Abstract
The purpose of this retrospective study was to gain insight into the contribution of the dorsolateral pons to the coordination of swallowing and breathing in awake goats. In 4 goats, cannulas were chronically implanted bilaterally through the lateral (LPBN) and medial (MPBN) parabrachial nuclei just dorsal to the Kölliker-Fuse nucleus (KFN). After >2weeks recovery from this surgery, the goats were studied for 5½h on a control day, and on separate days after receiving 1 and 10μl injections of ibotenic acid (IA) separated by 1week. The frequency of swallows did not change during the control and 1μl IA studies, but after injection of 10μl IA, there was a transient 65% increase in frequency of swallows (P<0.05). Under control conditions swallows occurred throughout the respiratory cycle, where late-E swallows accounted for 67.6% of swallows. The distribution of swallow occurrence throughout the respiratory cycle was unaffected by IA injections. Consistent with the concept that swallowing is dominant over breathing, we found that swallows increased inspiratory (T(I)) and expiratory (T(E)) time and decreased tidal volume (V(T)) of the breath of the swallow (n) and/or the subsequent (n+1) breath. Injections of 10μl IA attenuated the normal increases in T(I) and T(E) and further attenuated V(T) of the n breath. Additionally, E and I swallows reset respiratory rhythm, but injection of 1 or 10μl IA progressively attenuated this resetting, suggesting a decreased dominance over respiratory motor output with increasing IA injections. Post mortem histological analysis revealed about 50% fewer (P<0.05) neurons remained in the KFN, LPBN, and MPBN in lesioned compared to control goats. We conclude that dorsolateral pontine nuclei have a modulatory role in a hypothesized holarchical neural network regulating swallowing and breathing particularly contributing to the normal dominance of swallowing over breathing in both rhythm and motor pattern generation.
Author List
Bonis JM, Neumueller SE, Marshall BD, Krause KL, Qian B, Pan LG, Hodges MR, Forster HVAuthors
Hubert V. Forster PhD Professor in the Physiology department at Medical College of WisconsinMatthew R. Hodges PhD Associate Professor in the Physiology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsDeglutition
Female
Goats
Ibotenic Acid
Pons
Pulmonary Ventilation
Respiration
Retrospective Studies
Wakefulness
View this publication's entry at the Pubmed website PMID: 21145433
