Faculty Collaboration Database

Multiple rostral medullary nuclei can influence breathing in awake goats. J Appl Physiol (1985) 2001 Aug;91(2):777-88

Date

07/18/2001

Pubmed ID

11457794

DOI

10.1152/jappl.2001.91.2.777

Scopus ID

2-s2.0-0034923792 (requires institutional sign-in at Scopus site)   20 Citations

Abstract

The purpose of this study was to determine the effect on breathing of neuronal dysfunction in the retrotrapezoid (RTN), facial (FN), gigantocellularis reticularis (RGN), or vestibular (VN) nuclei of adult awake goats. Microtubules were chronically implanted to induce neuronal dysfunction by microinjection of an excitatory amino acid (EAA) receptor antagonist or a neurotoxin. The EAA receptor antagonist had minimal effect on eupneic breathing, but 8--10 days after injection of the neurotoxin, 7 of 10 goats hypoventilated (arterial PCO(2) increased 3.2 +/- 0.7 Torr). Overall there were no significant (P > 0.10) effects of the EAA receptor antagonist on CO(2) sensitivity. However, for all nuclei, > or =66% of the antagonist injections altered CO(2) sensitivity by more than the normal 12.7 +/- 1.6% day-to-day variation. These changes were not uniform, inasmuch as the antagonist increased (RTN, n = 2; FN, n = 7; RGN, n = 6; VN, n = 1) or decreased (RTN, n = 2; RGN, n = 3; VN, n = 2) CO(2) sensitivity. Ten days after injection of the neurotoxin into the FN (n = 3) or RGN (n = 5), CO(2) sensitivity was also reduced. Neuronal dysfunction also did not have a uniform effect on the exercise arterial PCO(2) response, and there was no correlation between effects on CO(2) sensitivity and the exercise hyperpnea. We conclude that there is a heterogeneous population of neurons in these rostral medullary nuclei (or adjacent tissue) that can affect breathing in the awake state, possibly through chemoreception or chemoreceptor-related mechanisms.

Author List

Wenninger JM, Pan LG, Martino P, Geiger L, Hodges M, Serra A, Feroah TR, Forster HV

Authors

Hubert V. Forster PhD Professor in the Physiology department at Medical College of Wisconsin
Matthew R. Hodges PhD Professor in the Physiology department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

2-Amino-5-phosphonovalerate
Animals
Blood Pressure
Carbon Dioxide
Electromyography
Excitatory Amino Acid Antagonists
Female
Goats
Heart Rate
Kynurenic Acid
Male
Medulla Oblongata
Microinjections
Neurons
Orchiectomy
Oxygen Consumption
Quinoxalines
Respiratory Mechanics
Respiratory Muscles
Tidal Volume
Vestibular Nuclei