Volume 14 Supplement 1

Abstracts from the Twenty Second Annual Computational Neuroscience Meeting: CNS*2013

Open Access

Control of breathing by interacting pontine and pulmonary feedback loops

  • Yaroslav I Molkov1Email author,
  • Bartholomew J Bacak2,
  • Thomas E Dick3 and
  • Ilya A Rybak2
BMC Neuroscience201314(Suppl 1):P338

DOI: 10.1186/1471-2202-14-S1-P338

Published: 8 July 2013

The medullary respiratory network generates respiratory rhythm via sequential phase switching, which in turn is controlled by multiple feedbacks including those from the pons and nucleus tractus solitarii; the latter mediates pulmonary afferent feedback to the medullary circuits. It is hypothesized that both pontine and pulmonary feedback pathways operate via activation of medullary respiratory neurons that are critically involved in phase switching. Moreover, the pontine and pulmonary control loops interact, so that pulmonary afferents control the gain of pontine influence of the respiratory pattern.

We used an established computational model of the respiratory network [1] and extended it by incorporating pontine circuits and pulmonary feedback (Figure 1). In the extended model, the pontine neurons receive phasic excitatory activation from, and provide feedback to, medullary respiratory neurons responsible for the onset and termination of inspiration. The model was used to study the effects of: (1) "vagotomy" (removal of pulmonary feedback), (2) suppression of pontine activity attenuating pontine feedback, and (3) these perturbations applied together on the respiratory pattern and durations of inspiration (T I ) and expiration (T E ).
https://static-content.springer.com/image/art%3A10.1186%2F1471-2202-14-S1-P338/MediaObjects/12868_2013_Article_3272_Fig1_HTML.jpg
Figure 1

A general schematic diagram representing the system with two interacting feedback loops.

In our model: (a) the simulated vagotomy resulted in increases of both T I and T E , (b) the suppression of pontine-medullary interactions led to the prolongation of T I at relatively constant, but variable T E , and (c) these perturbations applied together resulted in "apneusis", characterized by a significantly prolonged T I . The results of modeling were compared with, and provided a reasonable explanation for, multiple experimental data. The model was able to reproduce the experimentally demonstrated changes in T I and T E and phrenic pattern following vagotomy and/or pontine suppression by NMDA receptor blockers MK801and AP-5. According to the model these changes reflect the characteristic changes in the balance between the pontine and pulmonary feedback mechanisms involved in control of breathing during various cardio-respiratory disorders and diseases.

Abbreviations

AP-5 - amino-5-phosphonovaleric acid: 

NMDA receptor antagonist

BötC: 

Bötzinger Complex

E: 

Expiratory or Expiration

I: 

Inspiratory or Inspiration

KF: 

Kölliker-Fuse nucleus

MK801 - dizocilpine maleate: 

NMDA receptor antagonist

NTS: 

Nucleus Tractus Solitarii

PBN: 

ParaBrachial Nucleus

PSRs: 

Pulmonary Stretch Receptors

VRC: 

Ventral Respiratory Column

VRG: 

Ventral Respiratory Group.

Declarations

Acknowledgements

This study was supported by the National Institutes of Health: grants R33 HL087377, R33 HL087379, R01 NS057815, and R01 NS069220.

Authors’ Affiliations

(1)
Department of Mathematical Sciences, Indiana University - Purdue University
(2)
Department of Neurobiology and Anatomy, Drexel University College of Medicine
(3)
Departments of Medicine and Neurosciences, Case Western Reserve University

References

  1. Smith JC, Abdala AP, Koizumi H, Rybak IA, Paton JF: Spatial and functional architecture of the mammalian brain stem respiratory network: a hierarchy of three oscillatory mechanisms. J Neurophysiol. 2007, 98: 3370-3387. 10.1152/jn.00985.2007.PubMed CentralView ArticlePubMedGoogle Scholar

Copyright

© Molkov et al; licensee BioMed Central Ltd. 2013

This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

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