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de Souza JGV, de Souza DP, da Silva CAA, Martins Sá RW, Paton JFR, da Silva MP, Moraes DJA. Electrophysiological Properties and Morphology of Cardiac and Pulmonary Motoneurons within the Dorsal Motor Nucleus of the Vagus of Rats. Neuroscience 2024; 551:153-165. [PMID: 38821242 DOI: 10.1016/j.neuroscience.2024.05.038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2024] [Revised: 05/24/2024] [Accepted: 05/27/2024] [Indexed: 06/02/2024]
Abstract
The dorsal motor nucleus of the vagus (DMV) contains parasympathetic motoneurons that project to the heart and lungs. These motoneurons control ventricular excitability/contractility and airways secretions/blood flow, respectively. However, their electrophysiological properties, morphology and synaptic input activity remain unknown. One important ionic current described in DMV motoneurons controlling their electrophysiological behaviour is the A-type mediated by voltage-dependent K+ (Kv) channels. Thus, we compared the electrophysiological properties, synaptic activity, morphology, A-type current density, and single cell expression of Kv subunits, that contribute to macroscopic A-type currents, between DMV motoneurons projecting to either the heart or lungs of adult male rats. Using retrograde labelling, we visualized distinct DMV motoneurons projecting to the heart or lungs in acutely prepared medullary slices. Subsequently, whole cell recordings, morphological reconstruction and single motoneuron qRT-PCR studies were performed. DMV pulmonary motoneurons were more depolarized, electrically excitable, presented higher membrane resistance, broader action potentials and received greater excitatory synaptic inputs compared to cardiac DMV motoneurons. These differences were in part due to highly branched dendritic complexity and lower magnitude of A-type K+ currents. By evaluating expression of channels that mediate A-type currents from single motoneurons, we demonstrated a lower level of Kv4.2 in pulmonary versus cardiac motoneurons, whereas Kv4.3 and Kv1.4 levels were similar. Thus, with the distinct electrical, morphological, and molecular properties of DMV cardiac and pulmonary motoneurons, we surmise that these cells offer a new vista of opportunities for genetic manipulation providing improvement of parasympathetic function in cardiorespiratory diseases such heart failure and asthma.
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Affiliation(s)
- Júlia G V de Souza
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Daniel P de Souza
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Carlos A A da Silva
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Renato W Martins Sá
- School of Medicine of Ribeirão Preto, Department of Physiology, University of São Paulo, Ribeirão Preto, SP, Brazil
| | - Julian F R Paton
- Manaaki Manawa - The Centre for Heart Research, Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Melina P da Silva
- Department of Biophysics, Paulista School of Medicine, Federal University of São Paulo, São Paulo, SP, Brazil.
| | - Davi J A Moraes
- Department of Physiology and Biophysics, Biomedical Science Institute, University of São Paulo, São Paulo, SP, Brazil.
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Iring A, Baranyi M, Iring-Varga B, Mut-Arbona P, Gál ZT, Nagy D, Hricisák L, Varga J, Benyó Z, Sperlágh B. Blood oxygen regulation via P2Y12R expressed in the carotid body. Respir Res 2024; 25:61. [PMID: 38281036 PMCID: PMC10821555 DOI: 10.1186/s12931-024-02680-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 01/03/2024] [Indexed: 01/29/2024] Open
Abstract
BACKGROUND Peripheral blood oxygen monitoring via chemoreceptors in the carotid body (CB) is an integral function of the autonomic cardiorespiratory regulation. The presence of the purinergic P2Y12 receptor (P2Y12R) has been implicated in CB; however, the exact role of the receptor in O2 sensing and signal transduction is unknown. METHODS The presence of P2Y12R was established by immunoblotting, RT qPCR and immunohistochemistry. Primary glomus cells were used to assess P2Y12R function during hypoxia and hypercapnia, where monoamines were measured by HPLC; calcium signal was recorded utilizing OGB-1 and N-STORM Super-Resolution System. Ingravescent hypoxia model was tested in anaesthetized mice of mixed gender and cardiorespiratory parameters were recorded in control and receptor-deficient or drug-treated experimental animals. RESULTS Initially, the expression of P2Y12R in adult murine CB was confirmed. Hypoxia induced a P2Y12R-dependent release of monoamine transmitters from isolated CB cells. Receptor activation with the endogenous ligand ADP promoted release of neurotransmitters under normoxic conditions, while blockade disrupted the amplitude and duration of the intracellular calcium concentration. In anaesthetised mice, blockade of P2Y12R expressed in the CB abrogated the initiation of compensatory cardiorespiratory changes in hypoxic environment, while centrally inhibited receptors (i.e. microglial receptors) or receptor-deficiency induced by platelet depletion had limited influence on the physiological adjustment to hypoxia. CONCLUSIONS Peripheral P2Y12R inhibition interfere with the complex mechanisms of acute oxygen sensing by influencing the calcium signalling and the release of neurotransmitter molecules to evoke compensatory response to hypoxia. Prospectively, the irreversible blockade of glomic receptors by anti-platelet drugs targeting P2Y12Rs, propose a potential, formerly unrecognized side-effect to anti-platelet medications in patients with pulmonary morbidities.
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Affiliation(s)
- András Iring
- Laboratory of Molecular Pharmacology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary.
- Institute of Translational Medicine, Semmelweis University, Budapest, 1094, Hungary.
| | - Mária Baranyi
- Laboratory of Molecular Pharmacology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Bernadett Iring-Varga
- Laboratory of Molecular Pharmacology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, 1085, Hungary
| | - Paula Mut-Arbona
- Laboratory of Molecular Pharmacology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, 1085, Hungary
| | - Zsuzsanna T Gál
- Laboratory of Molecular Pharmacology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
| | - Dorina Nagy
- Institute of Translational Medicine, Semmelweis University, Budapest, 1094, Hungary
- Cerebrovascular and Neurocognitive Disorders Research Group, Hungarian Research Network, Semmelweis University (HUN-REN-SU), Budapest, 1094, Hungary
| | - László Hricisák
- Institute of Translational Medicine, Semmelweis University, Budapest, 1094, Hungary
- Cerebrovascular and Neurocognitive Disorders Research Group, Hungarian Research Network, Semmelweis University (HUN-REN-SU), Budapest, 1094, Hungary
| | - János Varga
- Department of Pulmonology, Faculty of Medicine, Semmelweis University, Budapest, 1083, Hungary
| | - Zoltán Benyó
- Institute of Translational Medicine, Semmelweis University, Budapest, 1094, Hungary
- Cerebrovascular and Neurocognitive Disorders Research Group, Hungarian Research Network, Semmelweis University (HUN-REN-SU), Budapest, 1094, Hungary
| | - Beáta Sperlágh
- Laboratory of Molecular Pharmacology, HUN-REN Institute of Experimental Medicine, Budapest, 1083, Hungary
- János Szentágothai School of Neurosciences, Semmelweis University School of PhD Studies, Budapest, 1085, Hungary
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Gold OMS, Bardsley EN, Ponnampalam AP, Pauza AG, Paton JFR. Cellular basis of learning and memory in the carotid body. Front Synaptic Neurosci 2022; 14:902319. [PMID: 36046221 PMCID: PMC9420943 DOI: 10.3389/fnsyn.2022.902319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
The carotid body is the primary peripheral chemoreceptor in the body, and critical for respiration and cardiovascular adjustments during hypoxia. Yet considerable evidence now implicates the carotid body as a multimodal sensor, mediating the chemoreflexes of a wide range of physiological responses, including pH, temperature, and acidosis as well as hormonal, glucose and immune regulation. How does the carotid body detect and initiate appropriate physiological responses for these diverse stimuli? The answer to this may lie in the structure of the carotid body itself. We suggest that at an organ-level the carotid body is comparable to a miniature brain with compartmentalized discrete regions of clustered glomus cells defined by their neurotransmitter expression and receptor profiles, and with connectivity to defined reflex arcs that play a key role in initiating distinct physiological responses, similar in many ways to a switchboard that connects specific inputs to selective outputs. Similarly, within the central nervous system, specific physiological outcomes are co-ordinated, through signaling via distinct neuronal connectivity. As with the brain, we propose that highly organized cellular connectivity is critical for mediating co-ordinated outputs from the carotid body to a given stimulus. Moreover, it appears that the rudimentary components for synaptic plasticity, and learning and memory are conserved in the carotid body including the presence of glutamate and GABAergic systems, where evidence pinpoints that pathophysiology of common diseases of the carotid body may be linked to deviations in these processes. Several decades of research have contributed to our understanding of the central nervous system in health and disease, and we discuss that understanding the key processes involved in neuronal dysfunction and synaptic activity may be translated to the carotid body, offering new insights and avenues for therapeutic innovation.
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Argent LP, Bose A, Paton JFR. Intra-carotid body inter-cellular communication. J R Soc N Z 2022. [DOI: 10.1080/03036758.2022.2079681] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Liam P. Argent
- Manaaki Manawa – the Centre for Heart Research, Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Aabharika Bose
- Manaaki Manawa – the Centre for Heart Research, Department of Physiology, University of Auckland, Auckland, New Zealand
| | - Julian F. R. Paton
- Manaaki Manawa – the Centre for Heart Research, Department of Physiology, University of Auckland, Auckland, New Zealand
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