Control of breathing and blood pressure by parafacial neurons in conscious rats

dc.contributorUniversidade Estadual Paulista (UNESP)
dc.creatorTakakura, Ana C.
dc.creatorMoreira, Thiago S.
dc.creatorDe Paula, Patrícia M.
dc.creatorMenani, José Vanderlei
dc.creatorColombari, Eduardo
dc.date2014-05-27T11:27:30Z
dc.date2016-10-25T18:41:05Z
dc.date2014-05-27T11:27:30Z
dc.date2016-10-25T18:41:05Z
dc.date2013-01-01
dc.date.accessioned2017-04-06T02:07:47Z
dc.date.available2017-04-06T02:07:47Z
dc.identifierExperimental Physiology, v. 98, n. 1, p. 304-315, 2013.
dc.identifier0958-0670
dc.identifier1469-445X
dc.identifierhttp://hdl.handle.net/11449/74235
dc.identifierhttp://acervodigital.unesp.br/handle/11449/74235
dc.identifier10.1113/expphysiol.2012.065128
dc.identifierWOS:000313255900031
dc.identifier2-s2.0-84872201142
dc.identifierhttp://dx.doi.org/10.1113/expphysiol.2012.065128
dc.identifier.urihttp://repositorioslatinoamericanos.uchile.cl/handle/2250/895007
dc.descriptionNew Findings: • What is the central question of this study? The main purpose of the present manuscript was to investigate the cardiorespiratory responses to hypoxia or hypercapnia in conscious rats submitted to neuronal blockade of the parafacial region. We clearly showed that the integrity of parafacial region is important for the respiratory responses elicited by peripheral and central chemoreflex activation in freely behavior rats. • What is the main finding and its importance? Since the parafacial region is part of the respiratory rhythm generator, they are essential for postnatal survival, which is probably due to their contribution to chemoreception in conscious rats. The retrotrapezoid nucleus (RTN), located in the parafacial region, contains glutamatergic neurons that express the transcriptor factor Phox2b and that are suggested to be central respiratory chemoreceptors. Studies in anaesthetized animals or in vitro have suggested that RTN neurons are important in the control of breathing by influencing respiratory rate, inspiratory amplitude and active expiration. However, the contribution of these neurons to cardiorespiratory control in conscious rats is not clear. Male Holtzman rats (280-300 g, n= 6-8) with bilateral stainless-steel cannulae implanted into the RTN were used. In conscious rats, the microinjection of the ionotropic glutamatergic agonist NMDA (5 pmol in 50 nl) into the RTN increased respiratory frequency (by 42%), tidal volume (by 21%), ventilation (by 68%), peak expiratory flow (by 24%) and mean arterial pressure (MAP, increased by 16 ± 4, versus saline, 3 ± 2 mmHg). Bilateral inhibition of the RTN neurons with the GABAA agonist muscimol (100 pmol in 50 nl) reduced resting ventilation (52 ± 34, versus saline, 250 ± 56 ml min-1 kg-1 with absolute values) and attenuated the respiratory response to hypercapnia and hypoxia. Muscimol injected into the RTN slightly reduced resting MAP (decreased by 13 ± 7, versus saline, increased by 3 ± 2 mmHg), without changing the effects of hypercapnia or hypoxia on MAP and heart rate. The results suggest that RTN neurons activate facilitatory mechanisms important to the control of ventilation in resting, hypoxic or hypercapnic conditions in conscious rats. © 2012 The Authors. Experimental Physiology © 2012 The Physiological Society.
dc.languageeng
dc.relationExperimental Physiology
dc.rightsinfo:eu-repo/semantics/closedAccess
dc.subjectionotropic receptor agonist
dc.subjectmuscimol
dc.subjectn methyl dextro aspartic acid
dc.subjectanimal experiment
dc.subjectblood pressure
dc.subjectbreathing
dc.subjectbreathing rate
dc.subjectcell activation
dc.subjectchemoreceptor reflex
dc.subjectcontrolled study
dc.subjectheart rate
dc.subjecthypercapnia
dc.subjecthypoxia
dc.subjectin vivo study
dc.subjectmale
dc.subjectmean arterial pressure
dc.subjectnerve cell
dc.subjectnerve cell inhibition
dc.subjectnonhuman
dc.subjectpeak expiratory flow
dc.subjectrat
dc.subjectretrotrapezoid nucleus
dc.subjectSprague Dawley rat
dc.subjecttidal volume
dc.subjectAnimals
dc.subjectAnoxia
dc.subjectBlood Pressure
dc.subjectConsciousness
dc.subjectHypercapnia
dc.subjectMale
dc.subjectMuscimol
dc.subjectN-Methylaspartate
dc.subjectNeurons
dc.subjectRats
dc.subjectRats, Sprague-Dawley
dc.subjectReceptors, N-Methyl-D-Aspartate
dc.subjectRespiration
dc.subjectRespiratory Center
dc.titleControl of breathing and blood pressure by parafacial neurons in conscious rats
dc.typeOtro


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