Respiratory and sympathetic chemoreflex regulation by Kolliker-Fuse neurons in rats

Author(s)

Damasceno, Roselia S. ^[1] ; Takakura, Ana C. ^[2] ; Moreira, Thiago S. ^[1]

Affiliation

^[1] Univ Sao Paulo, Dept Physiol & Biophys, Inst Biomed Sci, BR-05508000 Sao Paulo - Brazil

^[2] Univ Sao Paulo, Dept Pharmacol, Inst Biomed Sci, BR-05508000 Sao Paulo - Brazil

• Document type: Journal article
• Source: PFLUGERS ARCHIV-EUROPEAN JOURNAL OF PHYSIOLOGY; v. 467, n. 2, p. 231-239, FEB 2015.
• Web of Science Citations: 5

Abstract

Chemoreceptor activation increases phrenic nerve activity (PNA) and sympathetic nerve activity (SNA). The dorsolateral pontine neurons, including the parabrachial nucleus and the Kolliker-Fuse (KF) region project to several brainstem areas involved in autonomic and respiratory regulation. Here the objective was to further test the hypothesis that the KF region could contribute to central and peripheral sympathetic chemoreflex activation. In urethane-anesthetized sino-aortic denervated or intact and vagotomized male Wistar rats (N = 7-8/group), hypercapnia (end-expiratory CO2 from 5 to 10 %) or KCN increased mean arterial pressure (MAP), splanchnic SNA, and PNA frequency and amplitude. Bilateral injection of muscimol (GABA-A agonist; 2 mM-50 nl) into the KF region increased resting PNA amplitude and reduced resting PNA frequency, without significant changes in resting MAP and SNA. Bilateral blockade of the KF region reduced the rise in MAP, sSNA, and PNA frequency and amplitude produced by hypercapnia or hypoxia. Our data suggest that the KF neurons could integrate and modulate breathing and sympathetic outflow during chemoreceptor activation. (AU)

• FAPESP's process: 10/19336-0 - Pontine mechanisms involved in cardiorespiratory control during central or peripheral chemoreceptors activation
• Grantee: Thiago dos Santos Moreira
• Support Opportunities: Regular Research Grants
• FAPESP's process: 10/09776-3 - Neural mechanisms involved in expiratory rhythm generator: possible involvement of the retrotrapezoid nucleus and the parafacial region
• Grantee: Ana Carolina Takakura Moreira
• Support Opportunities: Research Grants - Young Investigators Grants
• FAPESP's process: 10/15692-7 - Involvement of the Kolliker-Fuse in cardiorespiratory control during activation of central and peripheral chemoreceptors
• Grantee: Rosélia dos Santos Damasceno
• Support Opportunities: Scholarships in Brazil - Doctorate