1
|
Paradiso B, Pauza DH, Limback C, Ottaviani G, Thiene G. From Psychostasis to the Discovery of Cardiac Nerves: The Origins of the Modern Cardiac Neuromodulation Concept. BIOLOGY 2024; 13:266. [PMID: 38666878 PMCID: PMC11047897 DOI: 10.3390/biology13040266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/24/2024] [Revised: 04/09/2024] [Accepted: 04/15/2024] [Indexed: 04/28/2024]
Abstract
This review explores the historical development of cardiology knowledge, from ancient Egyptian psychostasis to the modern comprehension of cardiac neuromodulation. In ancient Egyptian religion, psychostasis was the ceremony in which the deceased was judged before gaining access to the afterlife. This ritual was also known as the "weighing of the heart" or "weighing of the soul". The Egyptians believed that the heart, not the brain, was the seat of human wisdom, emotions, and memory. They were the first to recognize the cardiocentric nature of the body, identifying the heart as the center of the circulatory system. Aristotle (fourth century BC) considered the importance of the heart in human physiology in his philosophical analyses. For Galen (third century AD), the heart muscle was the site of the vital spirit, which regulated body temperature. Cardiology knowledge advanced significantly in the 15th century, coinciding with Leonardo da Vinci and Vesalius's pioneering anatomical and physiological studies. It was William Harvey, in the 17th century, who introduced the concept of cardiac circulation. Servet's research and Marcello Malpighi's discovery of arterioles and capillaries provided a more detailed understanding of circulation. Richard Lower emerged as the foremost pioneer of experimental cardiology in the late 17th century. He demonstrated the heart's neural control by tying off the vagus nerve. In 1753, Albrecht von Haller, a professor at Göttingen, was the first to discover the heart's automaticity and the excitation of muscle fibers. Towards the end of the 18th century, Antonio Scarpa challenged the theories of Albrecht von Haller and Johann Bernhard Jacob Behrends, who maintained that the myocardium possessed its own "irritability", on which the heartbeat depended, and was independent of neuronal sensitivity. Instead, Scarpa argued that the heart required innervation to maintain life, refuting Galenic notions. In contemporary times, the study of cardiac innervation has regained prominence, particularly in understanding the post-acute sequelae of SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) infection (PASC), which frequently involves cardiorespiratory symptoms and dysregulation of the intrinsic cardiac innervation. Recently, it has been recognized that post-acute sequelae of acute respiratory infections (ARIs) due to other pathogens can also be a cause of long-term vegetative and somatic symptoms. Understanding cardiac innervation and modulation can help to recognize and treat long COVID and long non-COVID-19 (coronavirus disease 2019) ARIs. This analysis explores the historical foundations of cardiac neuromodulation and its contemporary relevance. By focusing on this concept, we aim to bridge the gap between historical understanding and modern applications. This will illuminate the complex interplay between cardiac function, neural modulation, cardiovascular health, and disease management in the context of long-term cardiorespiratory symptoms and dysregulation of intrinsic cardiac innervations.
Collapse
Affiliation(s)
- Beatrice Paradiso
- Lino Rossi Research Center, Department of Biomedical, Surgical and Dental Sciences, Faculty of Medicine and Surgery, University of Milan, 20122 Milan, Italy;
- Consultant Cyto/Histopathologist (Anatomic Pathologist) Anatomic Pathology Unit, Dolo Hospital Venice, 30031 Dolo, Italy
| | - Dainius H. Pauza
- Faculty of Medicine, Institute of Anatomy, Lithuanian University of Health Sciences Kaunas, 44307 Kaunas, Lithuania;
| | - Clara Limback
- Oxford University Hospitals, NHS Trust, Oxford OX3 7JH, UK;
| | - Giulia Ottaviani
- Lino Rossi Research Center, Department of Biomedical, Surgical and Dental Sciences, Faculty of Medicine and Surgery, University of Milan, 20122 Milan, Italy;
- Department of Biomedical, Surgical and Dental Sciences, Faculty of Medicine and Surgery, University of Milan, 20122 Milan, Italy
- Department of Pathology and Laboratory Medicine, McGovern Medical School, University of Texas Health Science Center at Houston, Houston, TX 77054, USA
| | - Gaetano Thiene
- Cardiovascular Pathology, Department of Cardiac, Thoracic, Vascular Sciences and Public Health, University of Padua, 35122 Padua, Italy;
| |
Collapse
|
2
|
Inokaitis H, Pauziene N, Pauza DH. The distribution of sinoatrial nodal cells and their innervation in the pig. Anat Rec (Hoboken) 2023; 306:2333-2344. [PMID: 35643929 DOI: 10.1002/ar.24998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 04/28/2022] [Accepted: 05/05/2022] [Indexed: 11/08/2022]
Abstract
The sinoatrial node (SAN) has been the object of interest of various studies. In experimental neurocardiology, the real challenge is the choice of the most appropriate animal model. Pig is routinely used animal due to its size and physiological features. Despite this, the anatomy and innervation of the pig SAN are not completely examined. This study analyses the distribution of SAN cells and their innervation in whole-mount preparations and the cross-sections of the pig right atrium. Our findings revealed the differences in the distribution of the SAN cells and their innervation pattern between pigs and other animals. The pig SAN myocytes were distributed around the root of the anterior vena cava. A meshwork of nerve fibers (NFs) in this area was four-fold denser compared to other right atrial areas and contained the adrenergic (positive for TH), cholinergic (positive for ChAT), nitrergic (positive for nNOS), and potentially sensory (positive for SP) NFs. The SAN area contained 98 ± 10 ganglia that involved 21 ± 2 neuronal somata per ganglion. The determined chemical phenotypes of ganglionic cells demonstrate their diversity in the pig SAN area as there were identified neuronal somata positive for ChAT, nNOS, TH, and simultaneously for ChAT/nNOS and ChAT/TH. Small intensively fluorescent cells were also abundant. The broad distribution of SAN cells, the chemical diversity, and the high density of neural components in the SAN area are comparable to the human one and, therefore, the pig may be considered as the appropriate animal model for experimental cardiology.
Collapse
Affiliation(s)
- Hermanas Inokaitis
- Faculty of Medicine, Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Neringa Pauziene
- Faculty of Medicine, Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Dainius H Pauza
- Faculty of Medicine, Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| |
Collapse
|
3
|
Zhang Y, Bizanti A, Harden SW, Chen J, Bendowski K, Hoover DB, Gozal D, Shivkumar K, Heal M, Tappan S, Cheng ZJ. Topographical mapping of catecholaminergic axon innervation in the flat-mounts of the mouse atria: a quantitative analysis. Sci Rep 2023; 13:4850. [PMID: 37029119 PMCID: PMC10082215 DOI: 10.1038/s41598-023-27727-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2022] [Accepted: 01/06/2023] [Indexed: 04/09/2023] Open
Abstract
The sympathetic nervous system is crucial for controlling multiple cardiac functions. However, a comprehensive, detailed neuroanatomical map of the sympathetic innervation of the heart is unavailable. Here, we used a combination of state-of-the-art techniques, including flat-mount tissue processing, immunohistochemistry for tyrosine hydroxylase (TH, a sympathetic marker), confocal microscopy and Neurolucida 360 software to trace, digitize, and quantitatively map the topographical distribution of the sympathetic postganglionic innervation in whole atria of C57Bl/6 J mice. We found that (1) 4-5 major extrinsic TH-IR nerve bundles entered the atria at the superior vena cava, right atrium (RA), left precaval vein and the root of the pulmonary veins (PVs) in the left atrium (LA). Although these bundles projected to different areas of the atria, their projection fields partially overlapped. (2) TH-IR axon and terminal density varied considerably between different sites of the atria with the greatest density of innervation near the sinoatrial node region (P < 0.05, n = 6). (3) TH-IR axons also innervated blood vessels and adipocytes. (4) Many principal neurons in intrinsic cardiac ganglia and small intensely fluorescent cells were also strongly TH-IR. Our work provides a comprehensive topographical map of the catecholaminergic efferent axon morphology, innervation, and distribution in the whole atria at single cell/axon/varicosity scale that may be used in future studies to create a cardiac sympathetic-brain atlas.
Collapse
Affiliation(s)
- Yuanyuan Zhang
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, BMS Building 20, Room 230, 4110 Libra Drive, Orlando, FL, 32816, USA
| | - Ariege Bizanti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, BMS Building 20, Room 230, 4110 Libra Drive, Orlando, FL, 32816, USA
| | - Scott W Harden
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, BMS Building 20, Room 230, 4110 Libra Drive, Orlando, FL, 32816, USA
| | - Jin Chen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, BMS Building 20, Room 230, 4110 Libra Drive, Orlando, FL, 32816, USA
| | - Kohlton Bendowski
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, BMS Building 20, Room 230, 4110 Libra Drive, Orlando, FL, 32816, USA
| | - Donald B Hoover
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, TN, 37614, USA
| | - David Gozal
- Department of Child Health and Child Health Research Institute, University of Missouri School of Medicine, Columbia, MO, 65201, USA
- Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, MO, 65201, USA
| | - Kalyanam Shivkumar
- Department of Medicine, Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California, Los Angeles, CA, 90095, USA
| | - Maci Heal
- MBF Bioscience, Williston, VT, 05495, USA
| | | | - Zixi Jack Cheng
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, BMS Building 20, Room 230, 4110 Libra Drive, Orlando, FL, 32816, USA.
| |
Collapse
|
4
|
Bizanti A, Zhang Y, Harden SW, Chen J, Hoover DB, Gozal D, Shivkumar K, Cheng ZJ. Catecholaminergic axon innervation and morphology in flat-mounts of atria and ventricles of mice. J Comp Neurol 2023; 531:596-617. [PMID: 36591925 PMCID: PMC10499115 DOI: 10.1002/cne.25444] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2022] [Revised: 11/29/2022] [Accepted: 12/01/2022] [Indexed: 01/03/2023]
Abstract
Sympathetic efferent axons regulate cardiac functions. However, the topographical distribution and morphology of cardiac sympathetic efferent axons remain insufficiently characterized due to the technical challenges involved in immunohistochemical labeling of the thick walls of the whole heart. In this study, flat-mounts of the left and right atria and ventricles of FVB mice were immunolabeled for tyrosine hydroxylase (TH), a marker of sympathetic nerves. Atrial and ventricular flat-mounts were scanned using a confocal microscope to construct montages. We found (1) In the atria: A few large TH-immunoreactive (IR) axon bundles entered both atria, branched into small bundles and then single axons that eventually formed very dense terminal networks in the epicardium, myocardium and inlet regions of great vessels to the atria. Varicose TH-IR axons formed close contact with cardiomyocytes, vessels, and adipocytes. Multiple intrinsic cardiac ganglia (ICG) were identified in the epicardium of both atria, and a subpopulation of the neurons in the ICG were TH-IR. Most TH-IR axons in bundles traveled through ICG before forming dense varicose terminal networks in cardiomyocytes. We did not observe varicose TH-IR terminals encircling ICG neurons. (2) In the left and right ventricles and interventricular septum: TH-IR axons formed dense terminal networks in the epicardium, myocardium, and vasculature. Collectively, TH labeling is achievable in flat-mounts of thick cardiac walls, enabling detailed mapping of catecholaminergic axons and terminal structures in the whole heart at single-cell/axon/varicosity scale. This approach provides a foundation for future quantification of the topographical organization of the cardiac sympathetic innervation in different pathological conditions.
Collapse
Affiliation(s)
- Ariege Bizanti
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Yuanyuan Zhang
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Scott W Harden
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Jin Chen
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| | - Donald B Hoover
- Department of Biomedical Sciences, Quillen College of Medicine, East Tennessee State University, Johnson City, Tennessee, USA
| | - David Gozal
- Department of Child Health and Child Health Research Institute, and Department of Medical Pharmacology and Physiology, University of Missouri School of Medicine, Columbia, Missouri, USA
| | - Kalyanam Shivkumar
- Department of Medicine, Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, University of California, Los Angeles, California, USA
| | - Zixi Jack Cheng
- Burnett School of Biomedical Sciences, College of Medicine, University of Central Florida, Orlando, Florida, USA
| |
Collapse
|
5
|
Sahoglu SG, Kazci YE, Karadogan B, Aydin MS, Nebol A, Turhan MU, Ozturk G, Cagavi E. High-resolution mapping of sensory fibers at the healthy and post-myocardial infarct whole transgenic hearts. J Neurosci Res 2023; 101:338-353. [PMID: 36517461 DOI: 10.1002/jnr.25150] [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: 07/07/2022] [Revised: 10/15/2022] [Accepted: 11/19/2022] [Indexed: 12/23/2022]
Abstract
The sensory nervous system is critical to maintain cardiac function. As opposed to efferent innervation, less is known about cardiac afferents. For this, we mapped the VGLUT2-expressing cardiac afferent fibers of spinal and vagal origin by using the VGLUT2::tdTomato double transgenic mouse as an approach to visualize the whole hearts both at the dorsal and ventral sides. For comparison, we colabeled mixed-sex transgenic hearts with either TUJ1 protein for global cardiac innervation or tyrosine hydroxylase for the sympathetic network at the healthy state or following ischemic injury. Interestingly, the nerve density for global and VGLUT2-expressing afferents was found significantly higher on the dorsal side compared to the ventral side. From the global nerve innervation detected by TUJ1 immunoreactivity, VGLUT2 afferent innervation was detected to be 15-25% of the total network. The detailed characterization of both the atria and the ventricles revealed a remarkable diversity of spinal afferent nerve ending morphologies of flower sprays, intramuscular endings, and end-net branches that innervate distinct anatomical parts of the heart. Using this integrative approach in a chronic myocardial infarct model, we showed a significant increase in hyperinnervation in the form of axonal sprouts for cardiac afferents at the infarct border zone, as well as denervation at distal sites of the ischemic area. The functional and physiological consequences of the abnormal sensory innervation remodeling post-ischemic injury should be further evaluated in future studies regarding their potential contribution to cardiac dysfunction.
Collapse
Affiliation(s)
- Sevilay Goktas Sahoglu
- Regenerative and Restorative Medical Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Neuroscience Program, Institute of Health Sciences, Istanbul Medipol University, Istanbul, Turkey.,Department of Medical Biology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Yusuf Enes Kazci
- Regenerative and Restorative Medical Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Neuroscience Program, Institute of Health Sciences, Istanbul Medipol University, Istanbul, Turkey.,Department of Medical Biology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey
| | - Behnaz Karadogan
- Regenerative and Restorative Medical Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
| | - Mehmet Serif Aydin
- Regenerative and Restorative Medical Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey
| | - Aylin Nebol
- Regenerative and Restorative Medical Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Department of Medical Biology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey.,Medical Biology and Genetics Program, Institute of Health Sciences, Istanbul Medipol University, Istanbul, Turkey
| | - Mehmet Ugurcan Turhan
- Department of Cardiovascular Surgery, Cerrahpasa School of Medicine, Istanbul University, Istanbul, Turkey
| | - Gurkan Ozturk
- Regenerative and Restorative Medical Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Department of Physiology, International School of Medicine, Istanbul Medipol University, İstanbul, Turkey
| | - Esra Cagavi
- Regenerative and Restorative Medical Research Center (REMER), Research Institute for Health Sciences and Technologies (SABITA), Istanbul Medipol University, Istanbul, Turkey.,Department of Medical Biology, School of Medicine, Istanbul Medipol University, Istanbul, Turkey.,Department of Medical Biology, International School of Medicine, Istanbul Medipol University, Istanbul, Turkey.,Medical Biology and Genetics Program, Institute of Health Sciences, Istanbul Medipol University, Istanbul, Turkey
| |
Collapse
|
6
|
Ragauskas T, Rysevaite-Kyguoliene K, Pauziene N, Inokaitis H, Pauza DH. Chemical phenotypes of intrinsic cardiac neurons in the newborn pig (Sus scrofa domesticus Erxleben, 1777). J Morphol 2021; 283:51-65. [PMID: 34727377 DOI: 10.1002/jmor.21426] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2021] [Revised: 09/28/2021] [Accepted: 10/30/2021] [Indexed: 11/12/2022]
Abstract
Intrinsic cardiac neurons (ICNs) are crucial cells in the neural regulation of heart rhythm, myocardial contractility, and coronary blood flow. ICNs exhibit diversity in their morphology and neurotransmitters that probably are age-dependent. Therefore, neuroanatomical heart studies have been currently focused on the identification of chemical phenotypes of ICNs to disclose their possible functions in heart neural regulation. Employing whole-mount immunohistochemistry, we examined ICNs from atria of the newborn pigs (Sus scrofa domesticus) as ICNs at this stage of development have never been neurochemically characterized so far. We found that the majority of the examined ICNs (>60%) were of cholinergic phenotype. Biphenotypic neuronal somata (NS), that is, simultaneously positive for two neuronal markers, were also rather common and distributed evenly within the sampled ganglia. Simultaneous positivity for cholinergic and adrenergic neuromarkers was specific in 16.4%, for cholinergic and nitrergic-in 3.5% of the examined NS. Purely either adrenergic or nitrergic ICNs were observed at 13% and 3.1%, correspondingly. Purely adrenergic and nitrergic NS were the most frequent in the ventral left atrial subplexus. Similarly to neuronal phenotype, sizes of NS also varied depending on the atrial region providing insights into their functional implications. Axons, but not NS, positive for classic sensory neuronal markers (vesicular glutamate transporter 2 and calcitonin gene-related peptide) were identified within epicardiac nerves and ganglia. Moreover, a substantial number of ICNs could not be attributed to any phenotype as they were not immunoreactive for antisera used in this study. Numerous dendrites with putative peptidergic and adrenergic contacts on cholinergic NS contributed to neuropil of ganglia. Our observations demonstrate that intrinsic cardiac ganglionated plexus is not fully developed in the newborn pig despite of dense network of neuronal processes and numerous signs of neural contacts within ganglia.
Collapse
Affiliation(s)
- Tomas Ragauskas
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | | | - Neringa Pauziene
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Hermanas Inokaitis
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - Dainius Haroldas Pauza
- Institute of Anatomy, Faculty of Medicine, Lithuanian University of Health Sciences, Kaunas, Lithuania
| |
Collapse
|
7
|
Kim MS, Monfredi O, Maltseva LA, Lakatta EG, Maltsev VA. β-Adrenergic Stimulation Synchronizes a Broad Spectrum of Action Potential Firing Rates of Cardiac Pacemaker Cells toward a Higher Population Average. Cells 2021; 10:2124. [PMID: 34440893 PMCID: PMC8391682 DOI: 10.3390/cells10082124] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Revised: 08/10/2021] [Accepted: 08/14/2021] [Indexed: 01/28/2023] Open
Abstract
The heartbeat is initiated by pacemaker cells residing in the sinoatrial node (SAN). SAN cells generate spontaneous action potentials (APs), i.e., normal automaticity. The sympathetic nervous system increases the heart rate commensurate with the cardiac output demand via stimulation of SAN β-adrenergic receptors (βAR). While SAN cells reportedly represent a highly heterogeneous cell population, the current dogma is that, in response to βAR stimulation, all cells increase their spontaneous AP firing rate in a similar fashion. The aim of the present study was to investigate the cell-to-cell variability in the responses of a large population of SAN cells. We measured the βAR responses among 166 single SAN cells isolated from 33 guinea pig hearts. In contrast to the current dogma, the SAN cell responses to βAR stimulation substantially varied. In each cell, changes in the AP cycle length were highly correlated (R2 = 0.97) with the AP cycle length before βAR stimulation. While, as expected, on average, the cells increased their pacemaker rate, greater responses were observed in cells with slower basal rates, and vice versa: cells with higher basal rates showed smaller responses, no responses, or even decreased their rate. Thus, βAR stimulation synchronized the operation of the SAN cell population toward a higher average rate, rather than uniformly shifting the rate in each cell, creating a new paradigm of βAR-driven fight-or-flight responses among individual pacemaker cells.
Collapse
Affiliation(s)
| | | | | | | | - Victor A. Maltsev
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Baltimore, MD 21224, USA; (M.S.K.); (O.M.); (L.A.M.); (E.G.L.)
| |
Collapse
|
8
|
Synchronized Cardiac Impulses Emerge From Heterogeneous Local Calcium Signals Within and Among Cells of Pacemaker Tissue. JACC Clin Electrophysiol 2021; 6:907-931. [PMID: 32819526 DOI: 10.1016/j.jacep.2020.06.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/19/2020] [Accepted: 06/24/2020] [Indexed: 12/11/2022]
Abstract
OBJECTIVES This study sought to identify subcellular Ca2+ signals within and among cells comprising the sinoatrial node (SAN) tissue. BACKGROUND The current paradigm of SAN impulse generation: 1) is that full-scale action potentials (APs) of a common frequency are initiated at 1 site and are conducted within the SAN along smooth isochrones; and 2) does not feature fine details of Ca2+ signaling present in isolated SAN cells, in which small subcellular, subthreshold local Ca2+ releases (LCRs) self-organize to generate cell-wide APs. METHODS Immunolabeling was combined with a novel technique to detect the occurrence of LCRs and AP-induced Ca2+ transients (APCTs) in individual pixels (chronopix) across the entire mouse SAN images. RESULTS At high magnification, Ca2+ signals appeared markedly heterogeneous in space, amplitude, frequency, and phase among cells comprising an HCN4+/CX43- cell meshwork. The signaling exhibited several distinguishable patterns of LCR/APCT interactions within and among cells. Rhythmic APCTs that were apparently conducted within the meshwork were transferred to a truly conducting HCN4-/CX43+ network of striated cells via narrow functional interfaces where different cell types intertwine, that is, the SAN anatomic/functional unit. At low magnification, the earliest APCT of each cycle occurred within a small area of the HCN4 meshwork, and subsequent APCT appearance throughout SAN pixels was discontinuous and asynchronous. CONCLUSIONS The study has discovered a novel, microscopic Ca2+ signaling paradigm of SAN operation that has escaped detection using low-resolution, macroscopic tissue isochrones employed in prior studies: synchronized APs emerge from heterogeneous subcellular subthreshold Ca2+ signals, resembling multiscale complex processes of impulse generation within clusters of neurons in neuronal networks.
Collapse
|
9
|
Hanna P, Dacey MJ, Brennan J, Moss A, Robbins S, Achanta S, Biscola NP, Swid MA, Rajendran PS, Mori S, Hadaya JE, Smith EH, Peirce SG, Chen J, Havton LA, Cheng Z(J, Vadigepalli R, Schwaber J, Lux RL, Efimov I, Tompkins JD, Hoover DB, Ardell JL, Shivkumar K. Innervation and Neuronal Control of the Mammalian Sinoatrial Node a Comprehensive Atlas. Circ Res 2021; 128:1279-1296. [PMID: 33629877 PMCID: PMC8284939 DOI: 10.1161/circresaha.120.318458] [Citation(s) in RCA: 55] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
[Figure: see text].
Collapse
Affiliation(s)
- Peter Hanna
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
- UCLA Molecular, Cellular & Integrative Physiology Program, UCLA
| | - Michael J. Dacey
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
- UCLA Molecular, Cellular & Integrative Physiology Program, UCLA
| | - Jaclyn Brennan
- Bioengineering, George Washington University, Washington, DC
| | - Alison Moss
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA
| | - Shaina Robbins
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA
| | - Sirisha Achanta
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA
| | | | - Mohammed A. Swid
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
| | - Pradeep S. Rajendran
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
| | - Shumpei Mori
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
| | - Joseph E. Hadaya
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
| | | | | | - Jin Chen
- University of Central Florida, Burnett School of Biomedical Sciences, College of Medicine, Orlando, FL
| | - Leif A. Havton
- Neurology, Icahn School of Medicine at Mount Sinai, New York City, NY
- Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY
- VA RR&D National Center of Excellence for the Medical Consequences of Spinal and; Cord Injury and Neurology Service, James J. Peters Veterans Administration Medical Center, Bronx, NY
| | - Zixi (Jack) Cheng
- University of Central Florida, Burnett School of Biomedical Sciences, College of Medicine, Orlando, FL
| | - Rajanikanth Vadigepalli
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA
| | - James Schwaber
- Daniel Baugh Institute for Functional Genomics/Computational Biology, Department of Pathology, Anatomy, and Cell Biology, Thomas Jefferson University, Philadelphia, PA
| | - Robert L. Lux
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
| | - Igor Efimov
- Bioengineering, George Washington University, Washington, DC
| | - John D. Tompkins
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
| | - Donald B. Hoover
- Biomedical Sciences
- Center of Excellence in Inflammation, Infectious Disease and Immunity, James H. Quillen College of Medicine, East Tennessee State University
| | - Jeffrey L. Ardell
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
- UCLA Molecular, Cellular & Integrative Physiology Program, UCLA
| | - Kalyanam Shivkumar
- University of California Los Angeles (UCLA) Cardiac Arrhythmia Center and Neurocardiology Research Program of Excellence, Department of Medicine
- UCLA Molecular, Cellular & Integrative Physiology Program, UCLA
| |
Collapse
|
10
|
Navickaite I, Pauziene N, Pauza DH. Anatomical evidence of non-parasympathetic cardiac nitrergic nerve fibres in rat. J Anat 2021; 238:20-35. [PMID: 32790077 PMCID: PMC7755078 DOI: 10.1111/joa.13291] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Revised: 07/09/2020] [Accepted: 07/13/2020] [Indexed: 01/03/2023] Open
Abstract
Neuronal nitric oxide synthase (nNOS)-derived nitric oxide (NO) plays a major role in the neural control of circulation and in many cardiovascular diseases. However, the exact mechanism of how NO regulates these processes is still not fully understood. This study was designed to determine the possible sources of nitrergic nerve fibres supplying the heart attempting to imply their role in the cardiac neural control. Sections of medulla oblongata, vagal nerve, its rootlets and nodose ganglia, vagal cardiac branches, Th1 -Th5 spinal cord segments, dorsal root ganglia of C8 -Th5 spinal nerves, and stellate ganglia from 28 Wistar rats were examined applying double immunohistochemical staining for nNOS combined with choline acetyltransferase (ChAT), peripherin, substance P, calcitonin gene-related peptide, tyrosine hydroxylase or myelin basic protein. Our findings show that the most abundant population of purely nNOS-immunoreactive (IR) neuronal somata (NS) was observed in the nodose ganglia (37.4 ± 1.3%). A high number of nitrergic NFs spread along the vagal nerve and entered its cardiac branches. All nitrergic neuronal somata (NS) in the nucleus ambiguus were simultaneously immunoreactive (IR) to ChAT and composed only a small subset of neurons (6%). In the dorsal nucleus of vagal nerve, biphenotypic nNOS-IR/ChAT-IR neurons composed 7.0 ± 1.0%, while small purely nNOS-IR neurons were scarce. Nitrergic NS were plentifully distributed within the nuclei of solitary tract. In the examined dorsal root and stellate ganglia, a few nitrergic NS were sporadically present. The majority of sympathetic NS in the intermediolateral nucleus were simultaneously immunoreactive for nNOS and ChAT. In conclusion, an abundant population of nitrergic NS in the nodose ganglion implies that neuronal NO is involved in afferent cardiac innervation. Nevertheless, nNOS-IR neurons identified within vagal nuclei may play a role in the transmission of preganglionic parasympathetic nerve impulses.
Collapse
Affiliation(s)
- Ieva Navickaite
- Faculty of MedicineInstitute of AnatomyLithuanian University of Health SciencesKaunasLithuania
| | - Neringa Pauziene
- Faculty of MedicineInstitute of AnatomyLithuanian University of Health SciencesKaunasLithuania
| | - Dainius H. Pauza
- Faculty of MedicineInstitute of AnatomyLithuanian University of Health SciencesKaunasLithuania
| |
Collapse
|
11
|
MacDonald EA, Rose RA, Quinn TA. Neurohumoral Control of Sinoatrial Node Activity and Heart Rate: Insight From Experimental Models and Findings From Humans. Front Physiol 2020; 11:170. [PMID: 32194439 PMCID: PMC7063087 DOI: 10.3389/fphys.2020.00170] [Citation(s) in RCA: 57] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2019] [Accepted: 02/13/2020] [Indexed: 12/22/2022] Open
Abstract
The sinoatrial node is perhaps one of the most important tissues in the entire body: it is the natural pacemaker of the heart, making it responsible for initiating each-and-every normal heartbeat. As such, its activity is heavily controlled, allowing heart rate to rapidly adapt to changes in physiological demand. Control of sinoatrial node activity, however, is complex, occurring through the autonomic nervous system and various circulating and locally released factors. In this review we discuss the coupled-clock pacemaker system and how its manipulation by neurohumoral signaling alters heart rate, considering the multitude of canonical and non-canonical agents that are known to modulate sinoatrial node activity. For each, we discuss the principal receptors involved and known intracellular signaling and protein targets, highlighting gaps in our knowledge and understanding from experimental models and human studies that represent areas for future research.
Collapse
Affiliation(s)
- Eilidh A MacDonald
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada
| | - Robert A Rose
- Cumming School of Medicine, Libin Cardiovascular Institute of Alberta, University of Calgary, Calgary, AB, Canada
| | - T Alexander Quinn
- Department of Physiology and Biophysics, Dalhousie University, Halifax, NS, Canada.,School of Biomedical Engineering, Dalhousie University, Halifax, NS, Canada
| |
Collapse
|
12
|
Kim MS, Maltsev AV, Monfredi O, Maltseva LA, Wirth A, Florio MC, Tsutsui K, Riordon DR, Parsons SP, Tagirova S, Ziman BD, Stern MD, Lakatta EG, Maltsev VA. Heterogeneity of calcium clock functions in dormant, dysrhythmically and rhythmically firing single pacemaker cells isolated from SA node. Cell Calcium 2018; 74:168-179. [PMID: 30092494 DOI: 10.1016/j.ceca.2018.07.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2017] [Revised: 05/30/2018] [Accepted: 07/09/2018] [Indexed: 11/30/2022]
Abstract
Current understanding of how cardiac pacemaker cells operate is based mainly on studies in isolated single sinoatrial node cells (SANC), specifically those that rhythmically fire action potentials similar to the in vivo behavior of the intact sinoatrial node. However, only a small fraction of SANC exhibit rhythmic firing after isolation. Other SANC behaviors have not been studied. Here, for the first time, we studied all single cells isolated from the sinoatrial node of the guinea pig, including traditionally studied rhythmically firing cells ('rhythmic SANC'), dysrhythmically firing cells ('dysrhythmic SANC') and cells without any apparent spontaneous firing activity ('dormant SANC'). Action potential-induced cytosolic Ca2+ transients and spontaneous local Ca2+ releases (LCRs) were measured with a 2D camera. LCRs were present not only in rhythmically firing SANC, but also in dormant and dysrhythmic SANC. While rhythmic SANC were characterized by large LCRs synchronized in space and time towards late diastole, dysrhythmic and dormant SANC exhibited smaller LCRs that appeared stochastically and were widely distributed in time. β-adrenergic receptor (βAR) stimulation increased LCR size and synchronized LCR occurrences in all dysrhythmic and a third of dormant cells (25 of 75 cells tested). In response to βAR stimulation, these dormant SANC developed automaticity, and LCRs became coupled to spontaneous action potential-induced cytosolic Ca2+ transients. Conversely, dormant SANC that did not develop automaticity showed no significant change in average LCR characteristics. The majority of dysrhythmic cells became rhythmic in response to βAR stimulation, with the rate of action potential-induced cytosolic Ca2+ transients substantially increasing. In summary, isolated SANC can be broadly categorized into three major populations: dormant, dysrhythmic, and rhythmic. We interpret our results based on simulations of a numerical model of SANC operating as a coupled-clock system. On this basis, the two previously unstudied dysrhythmic and dormant cell populations have intrinsically partially or completely uncoupled clocks. Such cells can be recruited to fire rhythmically in response to βAR stimulation via increased rhythmic LCR activity and ameliorated coupling between the Ca2+ and membrane clocks.
Collapse
Affiliation(s)
- Mary S Kim
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Alexander V Maltsev
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Oliver Monfredi
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA; Department of Cardiovascular Electrophysiology, The Johns Hopkins Hospital, 1800 Orleans St, Baltimore, MD 21287, USA; Institute of Cardiovascular Sciences, University of Manchester, 46 Grafton St, Manchester M13 9NT, UK
| | - Larissa A Maltseva
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Ashley Wirth
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Maria Cristina Florio
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Kenta Tsutsui
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Daniel R Riordon
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Sean P Parsons
- Farncombe Institute, McMaster University, Hamilton, ON, Canada
| | - Syevda Tagirova
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Bruce D Ziman
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Michael D Stern
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Edward G Lakatta
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA
| | - Victor A Maltsev
- Laboratory of Cardiovascular Science, National Institute on Aging, NIH, Biomedical Research Center, 251 Bayview Blvd. Suite 100, Baltimore, MD 21224-6825, USA.
| |
Collapse
|
13
|
Allen E, Coote JH, Grubb BD, Batten TFC, Pauza DH, Ng GA, Brack KE. Electrophysiological effects of nicotinic and electrical stimulation of intrinsic cardiac ganglia in the absence of extrinsic autonomic nerves in the rabbit heart. Heart Rhythm 2018; 15:1698-1707. [PMID: 29800749 PMCID: PMC6207532 DOI: 10.1016/j.hrthm.2018.05.018] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Indexed: 11/18/2022]
Abstract
Background The intrinsic cardiac nervous system is a rich network of cardiac nerves that converge to form distinct ganglia and extend across the heart and is capable of influencing cardiac function. Objective The goals of this study were to provide a complete picture of the neurotransmitter/neuromodulator profile of the rabbit intrinsic cardiac nervous system and to determine the influence of spatially divergent ganglia on cardiac electrophysiology. Methods Nicotinic or electrical stimulation was applied at discrete sites of the intrinsic cardiac nerve plexus in the Langendorff-perfused rabbit heart. Functional effects on sinus rate and atrioventricular conduction were measured. Immunohistochemistry for choline acetyltransferase (ChAT), tyrosine hydroxylase, and/or neuronal nitric oxide synthase (nNOS) was performed using whole mount preparations. Results Stimulation within all ganglia produced either bradycardia, tachycardia, or a biphasic brady-tachycardia. Electrical stimulation of the right atrial and right neuronal cluster regions produced the largest chronotropic responses. Significant prolongation of atrioventricular conduction was predominant at the pulmonary vein-caudal vein region. Neurons immunoreactive (IR) only for ChAT, tyrosine hydroxylase, or nNOS were consistently located within the limits of the hilum and at the roots of the right cranial and right pulmonary veins. ChAT-IR neurons were most abundant (1946 ± 668 neurons). Neurons IR only for nNOS were distributed within ganglia. Conclusion Stimulation of intrinsic ganglia, shown to be of phenotypic complexity but predominantly of cholinergic nature, indicates that clusters of neurons are capable of independent selective effects on cardiac electrophysiology, therefore providing a potential therapeutic target for the prevention and treatment of cardiac disease.
Collapse
Affiliation(s)
- Emily Allen
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom; NIHR Leicester BRC, Glenfield Hospital, Leicester, United Kingdom
| | - John H Coote
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom
| | - Blair D Grubb
- Institute of Life and Human Sciences, University of Liverpool, Liverpool, United Kingdom
| | | | - Dainius H Pauza
- Institute of Anatomy, Lithuanian University of Health Sciences, Kaunas, Lithuania
| | - G André Ng
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom; NIHR Leicester BRC, Glenfield Hospital, Leicester, United Kingdom.
| | - Kieran E Brack
- Department of Cardiovascular Sciences, University of Leicester, Glenfield Hospital, Leicester, United Kingdom; NIHR Leicester BRC, Glenfield Hospital, Leicester, United Kingdom
| |
Collapse
|