These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Effects of vagotomy on hypoglossal and phrenic responses to hypercapnia in the decerebrate rat.
    Author: Ghali MG, Marchenko V.
    Journal: Respir Physiol Neurobiol; 2016 Oct; 232():13-21. PubMed ID: 27288057.
    Abstract:
    Hypercapnia characterizes a variety of physiological and pathological states and must be compensated effectively by the respiratory, cardiovascular, renal, and intra- and extracellular pH buffering systems to maintain homeostasis. Several studies have examined the respiratory response to hypercapnia, but contemporaneous changes in respiratory frequency and tidal volume prevent investigating the pure influence on respiratory amplitude. Therefore, we sought to test the effect of hypercapnia on hypoglossal (XII) and phrenic nerve (PN) inspiratory (Insp) and XII pre-inspiratory (pre-I) activities in vagus-intact and vagus-denervated animals. Experiments were performed on six artificially-ventilated unanesthetized pre-collicular decerebrate Sprague-Dawley adult male rats. Vagotomy under normocapnic conditions effected the consistent appearance of significant XII pre-I and a greater increase in XII than PN Insp amplitude. In the vagus-intact state, administration of a hypercapnic (5% CO2, 95% O2) gas mixture resulted in a greater increase in XII than PN Insp activity. In the vagotomized state, hypercapnia caused a drastic increase in XII pre-I and significant non-differential increases in both XII and PN Insp activity. The increase in XII pre-I was significantly greater than hypercapnia-induced increases in XII and PN Insp discharges. Following vagotomy, duration and amplitude of XII pre-I are potently modulated by CO2 tension. Based on our results, we conclude that vagal afferents exert differential inhibition of PN Insp and XII pre-I/Insp motor outputs. The role of vagal control in orchestration and optimization of respiratory response to hypercapnia is discussed.
    [Abstract] [Full Text] [Related] [New Search]