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5-HT neurons of the medullary raphe contribute to respiratory control in toads. Respir Physiol Neurobiol 2021; 293:103717. [PMID: 34119703 DOI: 10.1016/j.resp.2021.103717] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Revised: 05/12/2021] [Accepted: 06/08/2021] [Indexed: 11/23/2022]
Abstract
Air-breathing vertebrates undergo respiratory adjustments when faced with disturbances in the gas composition of the environment. In mammals, the medullary raphe nuclei are involved in the neuronal pathway that mediates the ventilatory responses to hypoxia and hypercarbia. We investigate whether the serotoninergic neurons of the medullary raphe nuclei of toads (Rhinella diptycha) play a functional role in respiratory control during resting conditions (room air), hypercarbia (5% CO2), and hypoxia (5% O2). The raphe nuclei were located and identified based on the location of the serotoninergic neurons in the brainstem. We then lesioned the medullary raphe (raphe pallidus, obscurus and magnus) with anti-SERT-SAP and measured ventilation in both control and lesioned groups and we observed that serotonin (5-HT) specific chemical lesions of the medullary raphe caused reduced respiratory responses to both hypercarbia and hypoxia. In summary, we report that the serotoninergic neurons of the medullary raphe of the cururu toad Rhinella diptycha participate in the chemoreflex responses during hypercarbia and hypoxia, but not during resting conditions. This current evidence in anurans, together with the available data in mammals, brings insights to the evolution of brain sites, such as the medullary raphe, involved in the ventilatory chemoreflex in vertebrates.
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Santin JM. Motor inactivity in hibernating frogs: Linking plasticity that stabilizes neuronal function to behavior in the natural environment. Dev Neurobiol 2019; 79:880-891. [DOI: 10.1002/dneu.22721] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2019] [Revised: 09/07/2019] [Accepted: 09/30/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Joseph M. Santin
- Department of BiologyUniversity of North Carolina at Greensboro Greensboro North Carolina
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Laouafa S, Perrin-Terrin AS, Jeton F, Elliot-Portal E, Tam R, Bodineau L, Voituron N, Soliz J. Pharmacological, but not genetic, alteration of neural Epo modifies the CO 2/H + central chemosensitivity in postnatal mice. Respir Physiol Neurobiol 2017; 242:73-79. [PMID: 28396201 DOI: 10.1016/j.resp.2017.04.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Revised: 03/24/2017] [Accepted: 04/05/2017] [Indexed: 11/24/2022]
Abstract
Cerebral erythropoietin (Epo) plays a crucial role for respiratory control in newborn rodents. We showed previously that soluble Epo receptor (sEpoR: an Epo antagonist) reduces basal ventilation and hypoxic hyperventilation at postnatal day 10 (P10) and in adult mice. However, at these ages (P10 and adulthood), Epo had no effect on central chemosensitivity. Nevertheless, it is known that the sensitivity to CO2/H+ during the mammalian respiratory network maturation process is age-dependent. Accordingly, in this study we wanted to test the hypothesis that cerebral Epo is involved in the breathing stimulation induced by the activation of central CO2/H+ chemoreceptors at earlier postnatal ages. To this end, en bloc brainstem-spinal cord preparations were obtained from P4 mice and the fictive breathing response to CO2-induced acidosis or metabolic acidosis was analyzed. This age (P4) was chosen because previous research from our laboratory showed that Epo altered (in a dose- and time-dependent manner) the fictive ventilation elicited in brainstem-spinal cord preparations. Moreover, as it was observed that peripheral chemoreceptors determined the respiratory sensitivity of central chemoreceptors to CO2, the use of this technique restricts our observations to central modulation. Our results did not show differences between preparations from control and transgenic animals (Tg21: overexpressing cerebral Epo; Epo-TAgh: cerebral Epo deficient mice). However, when Tg21 brainstem preparations were incubated for 1h with sEpoR, or with inhibitors of ERK/Akt (thus blocking the activation of the Epo molecular pathway), the fictive breathing response to CO2-induced acidosis was blunted. Our data suggest that variation of the Epo/sEpoR ratio is central to breathing modulation during CO2 challenges, and calls attention to clinical perspectives based on the use of Epo drugs at birth in hypoventilation cases.
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Affiliation(s)
- Sofien Laouafa
- Université Laval, Faculté de Médecine, Centre de Recherche Institut universitaire de cardiologie et de pneumologie de Québec, Département de Pédiatrie, Québec, QC, Canada; LEHNA, UMR CNRS 5023, Ecologie des Hydrosystèmes Naturels et Anthropisés, Université de Lyon, Université Lyon 1, ENTPE, 6 rue Raphael Dubois, 69622 Villeurbanne, France
| | - Anne-Sophie Perrin-Terrin
- Université Paris 13, Sorbonne Paris Cité, UFR SMBH, Laboratoire "Hypoxie et poumons", EA 2363, 93017 Bobigny, France; Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMR_S1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75013, Paris, France
| | - Florine Jeton
- Université Paris 13, Sorbonne Paris Cité, UFR SMBH, Laboratoire "Hypoxie et poumons", EA 2363, 93017 Bobigny, France
| | - Elizabeth Elliot-Portal
- Université Laval, Faculté de Médecine, Centre de Recherche Institut universitaire de cardiologie et de pneumologie de Québec, Département de Pédiatrie, Québec, QC, Canada; Molecular biology and Biotechnology Institute, Universidad Mayor de San Andres, La Paz, Bolivia
| | - Rose Tam
- Université Laval, Faculté de Médecine, Centre de Recherche Institut universitaire de cardiologie et de pneumologie de Québec, Département de Pédiatrie, Québec, QC, Canada
| | - Laurence Bodineau
- Sorbonne Universités, UPMC Univ Paris 06, INSERM, UMR_S1158 Neurophysiologie Respiratoire Expérimentale et Clinique, F-75013, Paris, France
| | - Nicolas Voituron
- Université Paris 13, Sorbonne Paris Cité, UFR SMBH, Laboratoire "Hypoxie et poumons", EA 2363, 93017 Bobigny, France
| | - Jorge Soliz
- Université Laval, Faculté de Médecine, Centre de Recherche Institut universitaire de cardiologie et de pneumologie de Québec, Département de Pédiatrie, Québec, QC, Canada; Molecular biology and Biotechnology Institute, Universidad Mayor de San Andres, La Paz, Bolivia.
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Santin JM, Hartzler LK. Reassessment of chemical control of breathing in undisturbed bullfrogs, Lithobates catesbeianus, using measurements of pulmonary ventilation. Respir Physiol Neurobiol 2016; 224:80-9. [DOI: 10.1016/j.resp.2015.09.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2015] [Revised: 09/26/2015] [Accepted: 09/27/2015] [Indexed: 11/28/2022]
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Kermorgant M, Lancien F, Mimassi N, Le Mével JC. Central ventilatory and cardiovascular actions of serotonin in trout. Respir Physiol Neurobiol 2013; 192:55-65. [PMID: 24325919 DOI: 10.1016/j.resp.2013.12.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2013] [Revised: 11/20/2013] [Accepted: 12/02/2013] [Indexed: 12/11/2022]
Abstract
This study was undertaken to investigate the central actions of 5-HT on ventilatory and cardiovascular variables in the unanesthetized trout. Compared to vehicle, intracerebroventricular injection (ICV) of 5-HT elevated the total ventilation. This elevation was due to its stimulatory action on ventilatory amplitude. Moreover, 5-HT produced a dose-dependent increase in mean dorsal aortic blood pressure (PDA) without change in heart rate (fH). Methysergide, a 5-HT1/5-HT2 receptor antagonist, reduced the hyperventilatory and hypertensive actions of 5-HT. 8-OH-2-(di-n-propylamino) tetralin, a 5-HT1A receptor agonist, increased PDA while α-methyl-5-HT, a 5-HT2 receptor agonist, elevated all ventilatory variables and increased PDA without changing fH. Intra-arterial injection of 5-HT was without effect on ventilation, but 5-HT initially produced hypotension followed by hypertension. These changes were accompanied by tachycardia. It remains to be determined whether endogenous 5-HT within the brain of trout may act as a potent neuroregulator causing stimulatory effects on cardio-ventilatory functions. In the periphery, 5-HT may act as local modulator involved in vasoregulatory mechanisms.
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Affiliation(s)
- Marc Kermorgant
- Université Européenne de Bretagne, Université de Brest, INSERM U650, Laboratoire de Traitement de l'Information Médicale, Laboratoire de Neurophysiologie, SFR 148 ScInBioS, Faculté de Médecine et des Sciences de la Santé, 22 avenue Camille Desmoulins, CS 93837, CHU de Brest, 29238 Brest Cedex 3, France
| | - Frédéric Lancien
- Université Européenne de Bretagne, Université de Brest, INSERM U650, Laboratoire de Traitement de l'Information Médicale, Laboratoire de Neurophysiologie, SFR 148 ScInBioS, Faculté de Médecine et des Sciences de la Santé, 22 avenue Camille Desmoulins, CS 93837, CHU de Brest, 29238 Brest Cedex 3, France
| | - Nagi Mimassi
- Université Européenne de Bretagne, Université de Brest, INSERM U650, Laboratoire de Traitement de l'Information Médicale, Laboratoire de Neurophysiologie, SFR 148 ScInBioS, Faculté de Médecine et des Sciences de la Santé, 22 avenue Camille Desmoulins, CS 93837, CHU de Brest, 29238 Brest Cedex 3, France
| | - Jean-Claude Le Mével
- Université Européenne de Bretagne, Université de Brest, INSERM U650, Laboratoire de Traitement de l'Information Médicale, Laboratoire de Neurophysiologie, SFR 148 ScInBioS, Faculté de Médecine et des Sciences de la Santé, 22 avenue Camille Desmoulins, CS 93837, CHU de Brest, 29238 Brest Cedex 3, France.
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Khemiri H, Seaborn T, Gestreau C, Soliz J. Erythropoietin and its antagonist regulate hypoxic fictive breathing in newborn mice. Respir Physiol Neurobiol 2012; 183:115-21. [PMID: 22684041 DOI: 10.1016/j.resp.2012.05.027] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2012] [Revised: 05/29/2012] [Accepted: 05/30/2012] [Indexed: 10/28/2022]
Abstract
Clinical use of erythropoietin in adult and newborn patients has revealed its involvement in neuroprotection, neurogenesis, and angiogenesis. More recently, we showed in adult mouse, that brain erythropoietin interacts with the major brainstem centers associated with respiration to enhance the ventilatory response to acute and chronic conditions of physiological hypoxia (e.g., as occurring at high altitude). However, whether brain erythropoietin is involved in breathing regulation in newborns remains unknown. In this study, en bloc brainstem-spinal cord preparations were obtained from mice at postnatal day 4. After various periods (30, 60, or 90 min) of incubation with 0, 25, or 250 U of erythropoietin, preparations were superfused with artificial cerebrospinal fluid bubbled with normoxic or hypoxic gas mixtures. The electrophysiological fictive breathing produced by axons at the C4 ventral root was next recorded. Our results show that erythropoietin attenuates the hypoxia-mediated decrease of the central respiratory activity and improves post-hypoxic recovery. Additional analysis revealed that the soluble erythropoietin receptor (the endogenous erythropoietin antagonist) dramatically decreases neural hypoxic respiratory activity, confirming the specific erythropoietin effect on respiratory drive. These results imply that erythropoietin exerts main modulation and maintenance of respiratory motor output during hypoxic and post-hypoxic challenges in 4-days old mice.
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Affiliation(s)
- Hanan Khemiri
- Départment de Pédiatrie, Centre de Recherche de l'Hôpital St-François d'Assise (CR-SFA), Centre Hospitalier Universitaire de Québec (CHUQ), Faculté de Médecine, Université Laval, Québec, QC, Canada.
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Milsom WK. The phylogeny of central chemoreception. Respir Physiol Neurobiol 2010; 173:195-200. [PMID: 20594933 DOI: 10.1016/j.resp.2010.05.022] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2010] [Revised: 05/27/2010] [Accepted: 05/27/2010] [Indexed: 11/18/2022]
Abstract
Respiratory chemoreceptors responsive to changes in CO(2)/H(+) appear to be present in all vertebrates from fish to birds and mammals. They appear to have arisen first in the periphery sensitive to the external environment. Thus, in most fish CO(2)/H(+) chemoreceptors reside primarily in the gills and respond to changes in aquatic rather than arterial P(CO)₂ . In the air-breathing tetrapods (amphibians, mammals, reptiles and birds), the branchial arches regress developmentally and the derivatives of the branchial arteries are now exclusively internal. The receptors associated with these arteries now sense only arterial (not environmental) P(CO)₂/pH . Central CO(2)/H(+) chemoreception also appears to have arisen with the advent of air breathing, presumably as a second line of defense. These receptors may have arisen multiple times in association with several (but not all) of the independent origins of air breathing in fishes. There is strong evidence for multiple central sites of CO(2)/H(+) sensing, at least in amphibians and mammals, suggesting that it may not only have originated multiple times in different species but also multiple times within a single species.
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Affiliation(s)
- W K Milsom
- Department of Zoology, University of British Columbia, Vancouver, BC, Canada.
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Bartman ME, Wilkerson JER, Johnson SM. 5-HT3 receptor-dependent modulation of respiratory burst frequency, regularity, and episodicity in isolated adult turtle brainstems. Respir Physiol Neurobiol 2010; 172:42-52. [PMID: 20399913 DOI: 10.1016/j.resp.2010.04.008] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2009] [Revised: 04/10/2010] [Accepted: 04/11/2010] [Indexed: 11/19/2022]
Abstract
To determine the role of central serotonin 5-HT(3) receptors in respiratory motor control, respiratory motor bursts were recorded from hypoglossal (XII) nerve rootlets on isolated adult turtle brainstems during bath-application of 5-HT(3) receptor agonists and antagonists. mCPBG and PBG (5-HT(3) receptor agonists) acutely increased XII burst frequency and regularity, and decreased bursts/episode. Tropisetron and MDL72222 (5-HT(3) antagonists) increased bursts/episode, suggesting endogenous 5-HT(3) receptor activation modulates burst timing in vitro. Tropisetron blocked all mCPBG effects, and the PBG-induced reduction in bursts/episode. Tropisetron application following mCPBG application did not reverse the long-lasting (2h) mCPBG-induced decrease in bursts/episode. We conclude that endogenous 5-HT(3) receptor activation regulates respiratory frequency, regularity, and episodicity in turtles and may induce a form of respiratory plasticity with the long-lasting changes in respiratory regularity.
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Affiliation(s)
- Michelle E Bartman
- Department of Comparative Biosciences, School of Veterinary Medicine, University of Wisconsin, 2015 Linden Drive, Madison, WI 53706, USA
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McDonald MD, Gilmour KM, Walsh PJ, Perry SF. Cardiovascular and respiratory reflexes of the gulf toadfish (Opsanus beta) during acute hypoxia. Respir Physiol Neurobiol 2010; 170:59-66. [DOI: 10.1016/j.resp.2009.12.012] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2009] [Revised: 12/11/2009] [Accepted: 12/26/2009] [Indexed: 10/20/2022]
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Gargaglioni LH, Bícegoa KC, Branco LGS. Brain monoaminergic neurons and ventilatory control in vertebrates. Respir Physiol Neurobiol 2009; 164:112-22. [PMID: 18550453 DOI: 10.1016/j.resp.2008.04.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Revised: 04/15/2008] [Accepted: 04/23/2008] [Indexed: 10/22/2022]
Abstract
Monoamines (noradrenaline (NA), adrenaline (AD), dopamine (DA) and serotonin (5-HT) are key neurotransmitters that are implicated in multiple physiological and pathological brain mechanisms, including control of respiration. The monoaminergic system is known to be widely distributed in the animal kingdom, which indicates a considerable degree of phylogenetic conservation of this system amongst vertebrates. Substantial progress has been made in uncovering the participation of the brain monoamines in the breathing regulation of mammals, since they are involved in the maturation of the respiratory network as well as in the modulation of its intrinsic and synaptic properties. On the other hand, for the non-mammalian vertebrates, most of the knowledge of central monoaminergic modulation in respiratory control, which is actually very little, has emerged from studies using anuran amphibians. This article reviews the available data on the role of brain monoaminergic systems in the control of ventilation in terrestrial vertebrates. Emphasis is given to the comparative aspects of the brain noradrenergic, adrenergic, dopaminergic and serotonergic neuronal groups in breathing regulation, after first briefly considering the distribution of monoaminergic neurons in the vertebrate brain.
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Affiliation(s)
- Luciane H Gargaglioni
- Department of Animal Morphology and Physiology, State University of Sao Paulo, FCAV at Jaboticabal, SP, Brazil.
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Fournier S, Kinkead R. Role of pontine neurons in central O(2) chemoreflex during development in bullfrogs (Lithobates catesbeiana). Neuroscience 2008; 155:983-96. [PMID: 18590803 DOI: 10.1016/j.neuroscience.2008.05.044] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2008] [Revised: 05/20/2008] [Accepted: 05/26/2008] [Indexed: 11/25/2022]
Abstract
The present study used an in vitro brainstem preparation from pre-metamorphic tadpoles and adult bullfrogs (Lithobates catesbeiana) to understand the neural mechanisms associated with central O(2) chemosensitivity and its maturation. In this species, brainstem hypoxia increases fictive lung ventilation in tadpoles but decreases in adults. Previous studies have shown that alpha(1)-adrenoceptor inactivation prevents these responses, suggesting that noradrenergic neurons are involved. We first tested the hypothesis that the pons (which includes noradrenergic neurons from the locus coeruleus; LC) plays a role in the lung burst frequency response to central hypoxia by comparing the effects of brainstem transection at the LC level between pre-metamorphic tadpoles and adults. Data show that brainstem transection prevents the lung burst frequency response in both stage groups. During development, the progressive decrease in the Na(+)/K(+)/Cl(-) co-transporter NKCC1 contributes to the maturation of neural networks. Because NKCC1 becomes activated during hypoxia, we then tested the hypothesis that NKCC1 contributes to maturation of the central O(2) chemoreflex. Double labeling experiments showed that the proportion of tyrosine hydroxylase positive neurons expressing NKCC1 in the LC decreases during development. Inactivation of NKCC1 with bumetanide bath application reversed the lung burst response to hypoxia in tadpoles. Bumetanide inhibited the response in adults. These data indicate that a structure within the pons (potentially the LC) is necessary to the central hypoxic chemoreflex and demonstrate that NKCC1 plays a role in central O(2) chemosensitivity and its maturation in this species.
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Affiliation(s)
- S Fournier
- Department of Pediatrics, Université Laval, Centre de Recherche du Centre Hospitalier Universitaire de Québec, Québec City, QC, Canada
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