Central chemoreceptors and neural mechanisms of cardiorespiratory control

The arterial partial pressure (P CO2) of carbon dioxide is virtually constant because of the close match between the metabolic production of this gas and its excretion via breathing. Blood gas homeostasis does not rely solely on changes in lung ventilation, but also to a considerable extent on circu...

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Main Authors: T.S. Moreira, A.C. Takakura, R.S. Damasceno, B. Falquetto, L.T. Totola, C.R. Sobrinho, D.T. Ragioto, F.P. Zolezi
Format: Article
Language:English
Published: Associação Brasileira de Divulgação Científica 2011-09-01
Series:Brazilian Journal of Medical and Biological Research
Subjects:
Online Access:http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000900009
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spelling doaj-337ca1b6d37745e2b956c33f42765a392020-11-24T21:16:01ZengAssociação Brasileira de Divulgação CientíficaBrazilian Journal of Medical and Biological Research0100-879X1414-431X2011-09-01449883889Central chemoreceptors and neural mechanisms of cardiorespiratory controlT.S. MoreiraA.C. TakakuraR.S. DamascenoB. FalquettoL.T. TotolaC.R. SobrinhoD.T. RagiotoF.P. ZoleziThe arterial partial pressure (P CO2) of carbon dioxide is virtually constant because of the close match between the metabolic production of this gas and its excretion via breathing. Blood gas homeostasis does not rely solely on changes in lung ventilation, but also to a considerable extent on circulatory adjustments that regulate the transport of CO2 from its sites of production to the lungs. The neural mechanisms that coordinate circulatory and ventilatory changes to achieve blood gas homeostasis are the subject of this review. Emphasis will be placed on the control of sympathetic outflow by central chemoreceptors. High levels of CO2 exert an excitatory effect on sympathetic outflow that is mediated by specialized chemoreceptors such as the neurons located in the retrotrapezoid region. In addition, high CO2 causes an aversive awareness in conscious animals, activating wake-promoting pathways such as the noradrenergic neurons. These neuronal groups, which may also be directly activated by brain acidification, have projections that contribute to the CO2-induced rise in breathing and sympathetic outflow. However, since the level of activity of the retrotrapezoid nucleus is regulated by converging inputs from wake-promoting systems, behavior-specific inputs from higher centers and by chemical drive, the main focus of the present manuscript is to review the contribution of central chemoreceptors to the control of autonomic and respiratory mechanisms.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000900009ChemoreflexCardiorespiratory responsesVentrolateral medullaSympathetic nerve activityPhrenic nerve activity
collection DOAJ
language English
format Article
sources DOAJ
author T.S. Moreira
A.C. Takakura
R.S. Damasceno
B. Falquetto
L.T. Totola
C.R. Sobrinho
D.T. Ragioto
F.P. Zolezi
spellingShingle T.S. Moreira
A.C. Takakura
R.S. Damasceno
B. Falquetto
L.T. Totola
C.R. Sobrinho
D.T. Ragioto
F.P. Zolezi
Central chemoreceptors and neural mechanisms of cardiorespiratory control
Brazilian Journal of Medical and Biological Research
Chemoreflex
Cardiorespiratory responses
Ventrolateral medulla
Sympathetic nerve activity
Phrenic nerve activity
author_facet T.S. Moreira
A.C. Takakura
R.S. Damasceno
B. Falquetto
L.T. Totola
C.R. Sobrinho
D.T. Ragioto
F.P. Zolezi
author_sort T.S. Moreira
title Central chemoreceptors and neural mechanisms of cardiorespiratory control
title_short Central chemoreceptors and neural mechanisms of cardiorespiratory control
title_full Central chemoreceptors and neural mechanisms of cardiorespiratory control
title_fullStr Central chemoreceptors and neural mechanisms of cardiorespiratory control
title_full_unstemmed Central chemoreceptors and neural mechanisms of cardiorespiratory control
title_sort central chemoreceptors and neural mechanisms of cardiorespiratory control
publisher Associação Brasileira de Divulgação Científica
series Brazilian Journal of Medical and Biological Research
issn 0100-879X
1414-431X
publishDate 2011-09-01
description The arterial partial pressure (P CO2) of carbon dioxide is virtually constant because of the close match between the metabolic production of this gas and its excretion via breathing. Blood gas homeostasis does not rely solely on changes in lung ventilation, but also to a considerable extent on circulatory adjustments that regulate the transport of CO2 from its sites of production to the lungs. The neural mechanisms that coordinate circulatory and ventilatory changes to achieve blood gas homeostasis are the subject of this review. Emphasis will be placed on the control of sympathetic outflow by central chemoreceptors. High levels of CO2 exert an excitatory effect on sympathetic outflow that is mediated by specialized chemoreceptors such as the neurons located in the retrotrapezoid region. In addition, high CO2 causes an aversive awareness in conscious animals, activating wake-promoting pathways such as the noradrenergic neurons. These neuronal groups, which may also be directly activated by brain acidification, have projections that contribute to the CO2-induced rise in breathing and sympathetic outflow. However, since the level of activity of the retrotrapezoid nucleus is regulated by converging inputs from wake-promoting systems, behavior-specific inputs from higher centers and by chemical drive, the main focus of the present manuscript is to review the contribution of central chemoreceptors to the control of autonomic and respiratory mechanisms.
topic Chemoreflex
Cardiorespiratory responses
Ventrolateral medulla
Sympathetic nerve activity
Phrenic nerve activity
url http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-879X2011000900009
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