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Filatova TS, Dzhumaniiazova I, Abramochkin DV. The metamorphosis of amphibian myocardium: moving to the heart of the matter. J Exp Biol 2024; 227:jeb247712. [PMID: 38916053 DOI: 10.1242/jeb.247712] [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: 03/08/2024] [Accepted: 04/26/2024] [Indexed: 06/26/2024]
Abstract
Amphibians are a classical object for physiological studies, and they are of great value for developmental studies owing to their transition from an aquatic larval form to an adult form with a terrestrial lifestyle. Axolotls (Ambystoma mexicanum) are of special interest for such studies because of their neoteny and facultative pedomorphosis, as in these animals, metamorphosis can be induced and fully controlled in laboratory conditions. It has been suggested that their metamorphosis, associated with gross anatomical changes in the heart, also involves physiological and electrical remodeling of the myocardium. We used whole-cell patch clamp to investigate possible changes caused by metamorphosis in electrical activity and major ionic currents in cardiomyocytes isolated from paedomorphic and metamorphic axolotls. T4-induced metamorphosis caused shortening of atrial and ventricular action potentials (APs), with no changes in resting membrane potential or maximum velocity of AP upstroke, favoring higher heart rate possible in metamorphic animals. Potential-dependent potassium currents in axolotl myocardium were represented by delayed rectifier currents IKr and IKs, and upregulation of IKs caused by metamorphosis probably underlies AP shortening. Metamorphosis was associated with downregulation of inward rectifier current IK1, probably serving to increase the excitability of myocardium in metamorphic animals. Metamorphosis also led to a slight increase in fast sodium current INa with no changes in its steady-state kinetics and to a significant upregulation of ICa in both atrial and ventricular cells, indicating stronger Ca2+ influx for higher cardiac contractility in metamorphic salamanders. Taken together, these changes serve to increase cardiac reserve in metamorphic animals.
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Affiliation(s)
- Tatiana S Filatova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Irina Dzhumaniiazova
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
| | - Denis V Abramochkin
- Department of Human and Animal Physiology, Lomonosov Moscow State University, Leninskiye gory, 1, 12, Moscow 119234, Russia
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Powell K, Lin K, Tambo W, Saavedra AP, Sciubba D, Al Abed Y, Li C. Trigeminal nerve stimulation: a current state-of-the-art review. Bioelectron Med 2023; 9:30. [PMID: 38087375 PMCID: PMC10717521 DOI: 10.1186/s42234-023-00128-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Accepted: 10/04/2023] [Indexed: 09/26/2024] Open
Abstract
Nearly 5 decades ago, the effect of trigeminal nerve stimulation (TNS) on cerebral blood flow was observed for the first time. This implication directly led to further investigations and TNS' success as a therapeutic intervention. Possessing unique connections with key brain and brainstem regions, TNS has been observed to modulate cerebral vasodilation, brain metabolism, cerebral autoregulation, cerebral and systemic inflammation, and the autonomic nervous system. The unique range of effects make it a prime therapeutic modality and have led to its clinical usage in chronic conditions such as migraine, prolonged disorders of consciousness, and depression. This review aims to present a comprehensive overview of TNS research and its broader therapeutic potentialities. For the purpose of this review, PubMed and Google Scholar were searched from inception to August 28, 2023 to identify a total of 89 relevant studies, both clinical and pre-clinical. TNS harnesses the release of vasoactive neuropeptides, modulation of neurotransmission, and direct action upon the autonomic nervous system to generate a suite of powerful multitarget therapeutic effects. While TNS has been applied clinically to chronic pathological conditions, these powerful effects have recently shown great potential in a number of acute/traumatic pathologies. However, there are still key mechanistic and methodologic knowledge gaps to be solved to make TNS a viable therapeutic option in wider clinical settings. These include bimodal or paradoxical effects and mechanisms, questions regarding its safety in acute/traumatic conditions, the development of more selective stimulation methods to avoid potential maladaptive effects, and its connection to the diving reflex, a trigeminally-mediated protective endogenous reflex. The address of these questions could overcome the current limitations and allow TNS to be applied therapeutically to an innumerable number of pathologies, such that it now stands at the precipice of becoming a ground-breaking therapeutic modality.
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Affiliation(s)
- Keren Powell
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Kanheng Lin
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
- Emory University, Atlanta, GA, USA
| | - Willians Tambo
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
- Elmezzi Graduate School of Molecular Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | | | - Daniel Sciubba
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Yousef Al Abed
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Chunyan Li
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, 350 Community Dr, Manhasset, NY, 11030, USA.
- Institute for Bioelectronic Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA.
- Elmezzi Graduate School of Molecular Medicine, The Feinstein Institutes for Medical Research, Manhasset, NY, USA.
- Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA.
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Nash C, Powell K, Lynch DG, Hartings JA, Li C. Nonpharmacological modulation of cortical spreading depolarization. Life Sci 2023:121833. [PMID: 37302793 DOI: 10.1016/j.lfs.2023.121833] [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: 04/21/2023] [Revised: 06/01/2023] [Accepted: 06/03/2023] [Indexed: 06/13/2023]
Abstract
AIMS Cortical spreading depolarization (CSD) is a wave of pathologic neuronal dysfunction that spreads through cerebral gray matter, causing neurologic disturbance in migraine and promoting lesion development in acute brain injury. Pharmacologic interventions have been found to be effective in migraine with aura, but their efficacy in acutely injured brains may be limited. This necessitates the assessment of possible adjunctive treatments, such as nonpharmacologic methods. This review aims to summarize currently available nonpharmacological techniques for modulating CSDs, present their mechanisms of action, and provide insight and future directions for CSD treatment. MAIN METHODS A systematic literature review was performed, generating 22 articles across 3 decades. Relevant data is broken down according to method of treatment. KEY FINDINGS Both pharmacologic and nonpharmacologic interventions can mitigate the pathological impact of CSDs via shared molecular mechanisms, including modulating K+/Ca2+/Na+/Cl- ion channels and NMDA, GABAA, serotonin, and CGRP ligand-based receptors and decreasing microglial activation. Preclinical evidence suggests that nonpharmacologic interventions, including neuromodulation, physical exercise, therapeutic hypothermia, and lifestyle changes can also target unique mechanisms, such as increasing adrenergic tone and myelination and modulating membrane fluidity, which may lend broader modulatory effects. Collectively, these mechanisms increase the electrical initiation threshold, increase CSD latency, slow CSD velocity, and decrease CSD amplitude and duration. SIGNIFICANCE Given the harmful consequences of CSDs, limitations of current pharmacological interventions to inhibit CSDs in acutely injured brains, and translational potentials of nonpharmacologic interventions to modulate CSDs, further assessment of nonpharmacologic modalities and their mechanisms to mitigate CSD-related neurologic dysfunction is warranted.
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Affiliation(s)
- Christine Nash
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Barnard College, New York, NY, USA
| | - Keren Powell
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA
| | - Daniel G Lynch
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA
| | - Jed A Hartings
- Department of Neurosurgery, University of Cincinnati, Cincinnati, OH, USA
| | - Chunyan Li
- Translational Brain Research Laboratory, The Feinstein Institutes for Medical Research, Manhasset, NY, USA; Donald and Barbara Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA; Department of Neurosurgery, Zucker School of Medicine at Hofstra/Northwell, Hempstead, NY, USA.
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An overview of the phylogeny of cardiorespiratory control in vertebrates with some reflections on the 'Polyvagal Theory'. Biol Psychol 2022; 172:108382. [PMID: 35777519 DOI: 10.1016/j.biopsycho.2022.108382] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Revised: 06/05/2022] [Accepted: 06/15/2022] [Indexed: 02/05/2023]
Abstract
Mammals show clear changes in heart rate linked to lung ventilation, characterized as respiratory sinus arrhythmia (RSA). These changes are controlled in part by variations in the level of inhibitory control exerted on the heart by the parasympathetic arm of the autonomic nervous system (PNS). This originates from preganglionic neurons in the nucleus ambiguous that supply phasic, respiration-related activity to the cardiac branch of the vagus nerve, via myelinated, efferent fibres with rapid conduction velocities. An elaboration of these central mechanisms, under the control of a 'vagal system' has been endowed by psychologists with multiple functions concerned with 'social engagement' in mammals and, in particular, humans. Long-term study of cardiorespiratory interactions (CRI) in other major groups of vertebrates has established that they all show both tonic and phasic control of heart rate, imposed by the PNS. This derives centrally from neurones located in variously distributed nuclei, supplying the heart via fast-conducting, myelinated, efferent fibres. Water-breathing vertebrates, which include fishes and larval amphibians, typically show direct, 1:1 CRI between heart beats and gill ventilation, controlled from the dorsal vagal motor nucleus. In air-breathing, ectothermic vertebrates, including reptiles, amphibians and lungfish, CRI mirroring RSA have been shown to improve oxygen uptake during phasic ventilation by changes in perfusion of their respiratory organs, due to shunting of blood over across their undivided hearts. This system may constitute the evolutionary basis of that generating RSA in mammals, which now lacks a major physiological role in respiratory gas exchange, due to their completely divided systemic and pulmonary circulations.
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Panneton WM, Gan Q. The Mammalian Diving Response: Inroads to Its Neural Control. Front Neurosci 2020; 14:524. [PMID: 32581683 PMCID: PMC7290049 DOI: 10.3389/fnins.2020.00524] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Accepted: 04/27/2020] [Indexed: 01/03/2023] Open
Abstract
The mammalian diving response (DR) is a remarkable behavior that was first formally studied by Laurence Irving and Per Scholander in the late 1930s. The DR is called such because it is most prominent in marine mammals such as seals, whales, and dolphins, but nevertheless is found in all mammals studied. It consists generally of breathing cessation (apnea), a dramatic slowing of heart rate (bradycardia), and an increase in peripheral vasoconstriction. The DR is thought to conserve vital oxygen stores and thus maintain life by directing perfusion to the two organs most essential for life-the heart and the brain. The DR is important, not only for its dramatic power over autonomic function, but also because it alters normal homeostatic reflexes such as the baroreceptor reflex and respiratory chemoreceptor reflex. The neurons driving the reflex circuits for the DR are contained within the medulla and spinal cord since the response remains after the brainstem transection at the pontomedullary junction. Neuroanatomical and physiological data suggesting brainstem areas important for the apnea, bradycardia, and peripheral vasoconstriction induced by underwater submersion are reviewed. Defining the brainstem circuit for the DR may open broad avenues for understanding the mechanisms of suprabulbar control of autonomic function in general, as well as implicate its role in some clinical states. Knowledge of the proposed diving circuit should facilitate studies on elite human divers performing breath-holding dives as well as investigations on sudden infant death syndrome (SIDS), stroke, migraine headache, and arrhythmias. We have speculated that the DR is the most powerful autonomic reflex known.
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Affiliation(s)
- W. Michael Panneton
- Department of Pharmacological and Physiological Science, School of Medicine, Saint Louis University, St. Louis, MO, United States
| | - Qi Gan
- Department of Pharmacological and Physiological Science, School of Medicine, Saint Louis University, St. Louis, MO, United States
- Department of Pediatrics, School of Medicine, Saint Louis University, St. Louis, MO, United States
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6
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Schulz S, Haueisen J, Bär KJ, Voss A. Altered Causal Coupling Pathways within the Central-Autonomic-Network in Patients Suffering from Schizophrenia. ENTROPY 2019; 21:e21080733. [PMID: 33267447 PMCID: PMC7515262 DOI: 10.3390/e21080733] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Revised: 07/19/2019] [Accepted: 07/24/2019] [Indexed: 12/28/2022]
Abstract
The multivariate analysis of coupling pathways within physiological (sub)systems focusing on identifying healthy and diseased conditions. In this study, we investigated a part of the central-autonomic-network (CAN) in 17 patients suffering from schizophrenia (SZO) compared to 17 age–gender matched healthy controls (CON) applying linear and nonlinear causal coupling approaches (normalized short time partial directed coherence, multivariate transfer entropy). Therefore, from all subjects continuous heart rate (successive beat-to-beat intervals, BBI), synchronized maximum successive systolic blood pressure amplitudes (SYS), synchronized calibrated respiratory inductive plethysmography signal (respiratory frequency, RESP), and the power PEEG of frontal EEG activity were investigated for 15 min under resting conditions. The CAN revealed a bidirectional coupling structure, with central driving towards blood pressure (SYS), and respiratory driving towards PEEG. The central-cardiac, central-vascular, and central-respiratory couplings are more dominated by linear regulatory mechanisms than nonlinear ones. The CAN showed significantly weaker nonlinear central-cardiovascular and central-cardiorespiratory coupling pathways, and significantly stronger linear central influence on the vascular system, and on the other hand significantly stronger linear respiratory and cardiac influences on central activity in SZO compared to CON, and thus, providing better understanding of the interrelationship of central and autonomic regulatory mechanisms in schizophrenia might be useful as a biomarker of this disease.
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Affiliation(s)
- Steffen Schulz
- Institute of Innovative Health Technologies, University of Applied Sciences, 07745 Jena, Germany
| | - Jens Haueisen
- Institute of Biomedical Engineering and Informatics, University of Technology, 98693 Ilmenau, Germany
| | - Karl-Jürgen Bär
- Department of Psychiatry and Psychotherapy, Pain and Autonomics-Integrative Research, University Hospital, 07745 Jena, Germany
| | - Andreas Voss
- Institute of Innovative Health Technologies, University of Applied Sciences, 07745 Jena, Germany
- Correspondence: ; Tel.: +49-3641-205625
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Hayano J, Yuda E. Pitfalls of assessment of autonomic function by heart rate variability. J Physiol Anthropol 2019; 38:3. [PMID: 30867063 PMCID: PMC6416928 DOI: 10.1186/s40101-019-0193-2] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Accepted: 03/05/2019] [Indexed: 12/16/2022] Open
Abstract
Although analysis of heart rate variability is widely used for the assessment of autonomic function, its fundamental framework linking low-frequency and high-frequency components of heart rate variability with sympathetic and parasympathetic autonomic divisions has developed in the 1980s. This simplified framework is no longer able to deal with much evidence about heart rate variability accumulated over the past half-century. This review addresses the pitfalls caused by the old framework and discusses the points that need attention in autonomic assessment by heart rate variability.
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Affiliation(s)
- Junichiro Hayano
- Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya, 467-8602, Japan.
| | - Emi Yuda
- Department of Medical Education, Nagoya City University Graduate School of Medical Sciences, 1 Kawasumi Mizuho-cho Mizuho-ku, Nagoya, 467-8602, Japan
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8
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Silvani A, Cerri M, Zoccoli G, Swoap SJ. Is Adenosine Action Common Ground for NREM Sleep, Torpor, and Other Hypometabolic States? Physiology (Bethesda) 2019; 33:182-196. [PMID: 29616880 DOI: 10.1152/physiol.00007.2018] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
This review compares two states that lower energy expenditure: non-rapid eye movement (NREM) sleep and torpor. Knowledge on mechanisms common to these states, and particularly on the role of adenosine in NREM sleep, may ultimately open the possibility of inducing a synthetic torpor-like state in humans for medical applications and long-term space travel. To achieve this goal, it will be important, in perspective, to extend the study to other hypometabolic states, which, unlike torpor, can also be experienced by humans.
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Affiliation(s)
- Alessandro Silvani
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna , Bologna , Italy
| | - Matteo Cerri
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna , Bologna , Italy.,National Institute of Nuclear Physics (INFN), Section of Bologna, Bologna , Italy
| | - Giovanna Zoccoli
- Department of Biomedical and Neuromotor Sciences, Alma Mater Studiorum, University of Bologna , Bologna , Italy
| | - Steven J Swoap
- Department of Biology, Williams College , Williamstown, Massachusetts
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Monteiro DA, Taylor EW, Sartori MR, Cruz AL, Rantin FT, Leite CAC. Cardiorespiratory interactions previously identified as mammalian are present in the primitive lungfish. SCIENCE ADVANCES 2018; 4:eaaq0800. [PMID: 29507882 PMCID: PMC5833999 DOI: 10.1126/sciadv.aaq0800] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 01/19/2018] [Indexed: 05/31/2023]
Abstract
The present study has revealed that the lungfish has both structural and functional features of its system for physiological control of heart rate, previously considered solely mammalian, that together generate variability (HRV). Ultrastructural and electrophysiological investigation revealed that the nerves connecting the brain to the heart are myelinated, conferring rapid conduction velocities, comparable to mammalian fibers that generate instantaneous changes in heart rate at the onset of each air breath. These respiration-related changes in beat-to-beat cardiac intervals were detected by complex analysis of HRV and shown to maximize oxygen uptake per breath, a causal relationship never conclusively demonstrated in mammals. Cardiac vagal preganglionic neurons, responsible for controlling heart rate via the parasympathetic vagus nerve, were shown to have multiple locations, chiefly within the dorsal vagal motor nucleus that may enable interactive control of the circulatory and respiratory systems, similar to that described for tetrapods. The present illustration of an apparently highly evolved control system for HRV in a fish with a proven ancient lineage, based on paleontological, morphological, and recent genetic evidence, questions much of the anthropocentric thinking implied by some mammalian physiologists and encouraged by many psychobiologists. It is possible that some characteristics of mammalian respiratory sinus arrhythmia, for which functional roles have been sought, are evolutionary relics that had their physiological role defined in ancient representatives of the vertebrates with undivided circulatory systems.
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Affiliation(s)
- Diana A. Monteiro
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, 13565-905 São Paulo, Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT FisComp), São Carlos, São Paulo, Brazil
| | - Edwin W. Taylor
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, 13565-905 São Paulo, Brazil
- School of Biosciences, University of Birmingham, Edgbaston, Birmingham B15 2TT, UK
| | - Marina R. Sartori
- Department of Zoology, São Paulo State University (UNESP), Rio Claro, São Paulo, Brazil
| | - André L. Cruz
- National Institute of Science and Technology in Comparative Physiology (INCT FisComp), São Carlos, São Paulo, Brazil
- Institute of Biology, Federal University of Bahia (UFBA), Salvador, Bahia, Brazil
| | - Francisco T. Rantin
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, 13565-905 São Paulo, Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT FisComp), São Carlos, São Paulo, Brazil
| | - Cleo A. C. Leite
- Department of Physiological Sciences, Federal University of São Carlos (UFSCar), São Carlos, 13565-905 São Paulo, Brazil
- National Institute of Science and Technology in Comparative Physiology (INCT FisComp), São Carlos, São Paulo, Brazil
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Schulz S, Bolz M, Bär KJ, Voss A. Central- and autonomic nervous system coupling in schizophrenia. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2016; 374:rsta.2015.0178. [PMID: 27044986 PMCID: PMC4822441 DOI: 10.1098/rsta.2015.0178] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 02/10/2016] [Indexed: 05/03/2023]
Abstract
The autonomic nervous system (ANS) dysfunction has been well described in schizophrenia (SZ), a severe mental disorder. Nevertheless, the coupling between the ANS and central brain activity has been not addressed until now in SZ. The interactions between the central nervous system (CNS) and ANS need to be considered as a feedback-feed-forward system that supports flexible and adaptive responses to specific demands. For the first time, to the best of our knowledge, this study investigates central-autonomic couplings (CAC) studying heart rate, blood pressure and electroencephalogram in paranoid schizophrenic patients, comparing them with age-gender-matched healthy subjects (CO). The emphasis is to determine how these couplings are composed by the different regulatory aspects of the CNS-ANS. We found that CAC were bidirectional, and that the causal influence of central activity towards systolic blood pressure was more strongly pronounced than such causal influence towards heart rate in paranoid schizophrenic patients when compared with CO. In paranoid schizophrenic patients, the central activity was a much stronger variable, being more random and having fewer rhythmic oscillatory components. This study provides a more in-depth understanding of the interplay of neuronal and autonomic regulatory processes in SZ and most likely greater insights into the complex relationship between psychotic stages and autonomic activity.
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Affiliation(s)
- Steffen Schulz
- Institute of Innovative Health Technologies, University of Applied Sciences, Jena, Germany
| | - Mathias Bolz
- Department of Child and Adolescent Psychiatry, Pain and Autonomics-Integrative Research, University Hospital, Jena, Germany
| | - Karl-Jürgen Bär
- Department of Psychiatry and Psychotherapy, Pain and Autonomics-Integrative Research, University Hospital, Jena, Germany
| | - Andreas Voss
- Institute of Innovative Health Technologies, University of Applied Sciences, Jena, Germany
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Carravieri A, Müller MS, Yoda K, Hayama SI, Yamamoto M. Dominant Parasympathetic Modulation of Heart Rate and Heart Rate Variability in a Wild-Caught Seabird. Physiol Biochem Zool 2016; 89:263-76. [PMID: 27327178 DOI: 10.1086/686894] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Heart rate (HR) and heart rate variability (HRV) provide noninvasive measures of the relative activity of the parasympathetic nervous system (PNS), which promotes self-maintenance and restoration, and the sympathetic nervous system (SNS), which prepares an animal for danger. The PNS decreases HR, whereas the SNS increases HR. The PNS and SNS also contribute to oscillations in heartbeat intervals at different frequencies, producing HRV. HRV promotes resilience and adjustment capacity in the organism to intrinsic and extrinsic changes. Measuring HRV can reveal the condition and emotional state of animals, including aspects of their stress physiology. Until now, the functioning of the PNS and SNS and their relationship with other physiological systems have been studied almost exclusively in humans. In this study, we tested their influence on HR and HRV for the first time in a wild-caught seabird, the streaked shearwater (Calonectris leucomelas). We analyzed electrocardiograms collected from birds carrying externally attached HR loggers and that received injections that pharmacologically blocked the PNS, the SNS, or both, as well as those that received a saline (sham) injection or no injection (control). The PNS strongly dominated modulation of HR and also HRV across all frequencies, whereas the SNS contributed only slightly to low-frequency oscillations. The saline injection itself acted as a stressor, causing a dramatic drop in PNS activity in HRV and an increase in HR, though PNS activity continued to dominate even during acute stress. Dominant PNS activity is expected for long-lived species, which should employ physiological strategies that minimize somatic deterioration coming from stress.
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12
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Bär KJ, Herbsleb M, Schumann A, de la Cruz F, Gabriel HW, Wagner G. Hippocampal-Brainstem Connectivity Associated with Vagal Modulation after an Intense Exercise Intervention in Healthy Men. Front Neurosci 2016; 10:145. [PMID: 27092046 PMCID: PMC4823309 DOI: 10.3389/fnins.2016.00145] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2016] [Accepted: 03/21/2016] [Indexed: 12/29/2022] Open
Abstract
Regular physical exercise leads to increased vagal modulation of the cardiovascular system. A combination of peripheral and central processes has been proposed to underlie this adaptation. However, specific changes in the central autonomic network have not been described in human in more detail. We hypothesized that the anterior hippocampus known to be influenced by regular physical activity might be involved in the development of increased vagal modulation after a 6 weeks high intensity intervention in young healthy men (exercise group: n = 17, control group: n = 17). In addition to the determination of physical capacity before and after the intervention, we used resting state functional magnetic resonance imaging and simultaneous heart rate variability assessment. We detected a significant increase of the power output at the anaerobic threshold of 11.4% (p < 0.001), the maximum power output Pmax of 11.2% (p < 0.001), and VO2max adjusted for body weight of 4.7% (p < 0.001) in the exercise group (EG). Comparing baseline (T0) and post-exercise (T1) values of parasympathetic modulation of the exercise group, we observed a trend for a decrease in heart rate (p < 0.06) and a significant increase of vagal modulation as indicated by RMSSD (p < 0.026) during resting state. In the whole brain analysis, we found that the connectivity pattern of the right anterior hippocampus (aHC) was specifically altered to the ventromedial anterior cortex, the dorsal striatum and to the dorsal vagal complex (DVC) in the brainstem. Moreover, we observed a highly significant negative correlation between increased RMSSD after exercise and decreased functional connectivity from the right aHC to DVC (r = -0.69, p = 0.003). This indicates that increased vagal modulation was associated with functional connectivity between aHC and the DVC. In conclusion, our findings suggest that exercise associated changes in anterior hippocampal function might be involved in increased vagal modulation.
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Affiliation(s)
- Karl-Jürgen Bär
- Psychiatric Brain and Body Research Group, Department of Psychiatry and Psychotherapy, University Hospital Jena Jena, Germany
| | - Marco Herbsleb
- Psychiatric Brain and Body Research Group, Department of Psychiatry and Psychotherapy, University Hospital JenaJena, Germany; Clinical Exercise Physiology, Department of Sports Medicine and Health Promotion, Friedrich-Schiller-University of JenaJena, Germany
| | - Andy Schumann
- Psychiatric Brain and Body Research Group, Department of Psychiatry and Psychotherapy, University Hospital Jena Jena, Germany
| | - Feliberto de la Cruz
- Psychiatric Brain and Body Research Group, Department of Psychiatry and Psychotherapy, University Hospital Jena Jena, Germany
| | - Holger W Gabriel
- Clinical Exercise Physiology, Department of Sports Medicine and Health Promotion, Friedrich-Schiller-University of Jena Jena, Germany
| | - Gerd Wagner
- Psychiatric Brain and Body Research Group, Department of Psychiatry and Psychotherapy, University Hospital Jena Jena, Germany
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Abstract
Evolution has endowed all humans with a continuum of innate, hard-wired, automatically activated defense behaviors, termed the defense cascade. Arousal is the first step in activating the defense cascade; flight or fight is an active defense response for dealing with threat; freezing is a flight-or-fight response put on hold; tonic immobility and collapsed immobility are responses of last resort to inescapable threat, when active defense responses have failed; and quiescent immobility is a state of quiescence that promotes rest and healing. Each of these defense reactions has a distinctive neural pattern mediated by a common neural pathway: activation and inhibition of particular functional components in the amygdala, hypothalamus, periaqueductal gray, and sympathetic and vagal nuclei. Unlike animals, which generally are able to restore their standard mode of functioning once the danger is past, humans often are not, and they may find themselves locked into the same, recurring pattern of response tied in with the original danger or trauma. Understanding the signature patterns of these innate responses--the particular components that combine to yield the given pattern of defense-is important for developing treatment interventions. Effective interventions aim to activate or deactivate one or more components of the signature neural pattern, thereby producing a shift in the neural pattern and, with it, in mind-body state. The process of shifting the neural pattern is the necessary first step in unlocking the patient's trauma response, in breaking the cycle of suffering, and in helping the patient to adapt to, and overcome, past trauma.
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Abstract
OBJECTIVE Conversion symptoms--functional neurological disturbances of body function--occur in association with extreme arousal, often in the context of emotional distress. The mechanisms that determine how and why such symptoms occur remain unknown. In this study, we used cardiac measures to assess arousal and cardiac autonomic regulation in children and adolescents who presented with acute conversion symptoms. METHODS Heart rate was recorded in 57 children and adolescents (41 girls; 8.5-18 years old) with acute conversion symptoms and 57 age- and sex-matched healthy controls, during a resting condition and then during tasks involving cognitive and emotional activation. Arousal and autonomic regulation were assessed by measures of heart rate and heart rate variability. Psychological measures included attachment and emotional distress. RESULTS Children and adolescents with conversion symptoms displayed higher autonomic arousal than did the controls, both at baseline and during task conditions (higher heart rate: baseline mean [standard deviation] = 82 [9.49] versus 74 [10.79] beats/min, p < .001; lower root mean squared successive differences-heart rate variability: 45.35 [27.97] versus 58.62 [25.69] ms(2), p = .012; and lower high-frequency heart rate variability: 6.50 [1.19] versus 7.01 [0.95] ln[ms(2)] p = .017), and decreased autonomic regulation (attenuation of heart rate increases across tasks). The baseline pattern of increased autonomic arousal was especially pronounced in children with coercive-preoccupied patterns of attachment. Autonomic measures were not correlated with measures of emotional distress. CONCLUSIONS High autonomic arousal may be a precondition for generating conversion symptoms. Functional dysregulations of the cardiac, respiratory, and circulatory systems may mediate fainting episodes and nonepileptic seizures, and aberrant patterns of functional connectivity between motor areas and central arousal systems may be responsible for generating motor conversion symptoms.
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15
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Taylor EW, Leite CAC, Sartori MR, Wang T, Abe AS, Crossley DA. The phylogeny and ontogeny of autonomic control of the heart and cardiorespiratory interactions in vertebrates. ACTA ACUST UNITED AC 2014; 217:690-703. [PMID: 24574385 DOI: 10.1242/jeb.086199] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Heart rate in vertebrates is controlled by activity in the autonomic nervous system. In spontaneously active or experimentally prepared animals, inhibitory parasympathetic control is predominant and is responsible for instantaneous changes in heart rate, such as occur at the first air breath following a period of apnoea in discontinuous breathers like inactive reptiles or species that surface to air breathe after a period of submersion. Parasympathetic control, exerted via fast-conducting, myelinated efferent fibres in the vagus nerve, is also responsible for beat-to-beat changes in heart rate such as the high frequency components observed in spectral analysis of heart rate variability. These include respiratory modulation of the heartbeat that can generate cardiorespiratory synchrony in fish and respiratory sinus arrhythmia in mammals. Both may increase the effectiveness of respiratory gas exchange. Although the central interactions generating respiratory modulation of the heartbeat seem to be highly conserved through vertebrate phylogeny, they are different in kind and location, and in most species are as yet little understood. The heart in vertebrate embryos possesses both muscarinic cholinergic and β-adrenergic receptors very early in development. Adrenergic control by circulating catecholamines seems important throughout development. However, innervation of the cardiac receptors is delayed and first evidence of a functional cholinergic tonus on the heart, exerted via the vagus nerve, is often seen shortly before or immediately after hatching or birth, suggesting that it may be coordinated with the onset of central respiratory rhythmicity and subsequent breathing.
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Affiliation(s)
- Edwin W Taylor
- Departamento de Zoologia, Instituto de Biociências, Universidade Estadual Paulista, Campus Rio Claro, São Paulo 13506-900, Brazil
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16
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Panneton WM. The mammalian diving response: an enigmatic reflex to preserve life? Physiology (Bethesda) 2014; 28:284-97. [PMID: 23997188 DOI: 10.1152/physiol.00020.2013] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mammalian diving response is a remarkable behavior that overrides basic homeostatic reflexes. It is most studied in large aquatic mammals but is seen in all vertebrates. Pelagic mammals have developed several physiological adaptations to conserve intrinsic oxygen stores, but the apnea, bradycardia, and vasoconstriction is shared with those terrestrial and is neurally mediated. The adaptations of aquatic mammals are reviewed here as well as the neural control of cardiorespiratory physiology during diving in rodents.
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Affiliation(s)
- W Michael Panneton
- Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, St. Louis, MO, USA.
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17
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Leite CAC, Taylor EW, Wang T, Abe AS, de Andrade DOV. Ablation of the ability to control the right-to-left cardiac shunt does not affect oxygen consumption, specific dynamic action or growth in rattlesnakes, Crotalus durissus. J Exp Biol 2013; 216:1881-9. [DOI: 10.1242/jeb.083840] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Summary
The morphologically undivided ventricle of the heart in non-crocodilian reptiles permits the mixing of oxygen-rich blood returning from the lungs and oxygen-poor blood from the systemic circulation. A possible functional significance for this intra-cardiac shunt has been debated for almost a century. Unilateral left vagotomy rendered the single effective pulmonary artery of the South American rattlesnake, Crotalus durissus, unable to adjust the magnitude of blood flow to the lung. The higher constant perfusion of the lung circulation and the incapability of adjusting R-L shunt in left-denervated snakes persisted over time, providing a unique model for investigation of the long-term consequences of cardiac shunting in a squamate. Oxygen uptake recorded at rest, during spontaneous and forced activity, was not affected by removing control of the cardiac shunt. Furthermore, metabolic rate and energetic balance during the post-prandial metabolic increment, plus the food conversion efficiency and growth rate were all similarly unaffected. These results show that control of cardiac shunting is not associated with a clear functional advantage in adjusting metabolic rate, effectiveness of digestion or growth rates.
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18
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De Vera L, Rial RV, Pereda E, González JJ. Autonomic mediation of the interdependence between variability signals of heart rate and blood pressure in the lizard Gallotia galloti. CAN J ZOOL 2012. [DOI: 10.1139/z2012-052] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Autonomic nervous system (ANS) involvement in the mediation of the synchronization between beat-to-beat RR interval variability (RRIV) and systolic blood pressure variability (SBPV) signals of the lizard Gallotia galloti (Oudart, 1839) was investigated through linear and nonlinear time series analysis methods in a pharmacological blockade context. The ANS blockers used were atropine, prazosin, and propranolol. The interdependence between the signals was quantified by means of the magnitude-squared coherence (MSC), which measures amplitude and phase linear synchronization; the phase lag index (PLI), which evaluates the phase synchronization; and the index L, which quantifies the generalized linear and nonlinear synchronization. Atropine decreased the PLI in the low-frequency (LF: 0.01–0.05 Hz) range; prazosin decreased the MSC in the medium-frequency (MF: 0.06–0.15 Hz) range; and propranolol did not alter any of the interdependence measures. It is suggested that (i) the cholinoceptor activity mediates the phase cardiovascular synchronization in the LF range; (ii) the α1-adrenoceptor activity mediates the amplitude and phase linear cardiovascular synchronization in the MF range; and (iii) the β-adrenoceptor activity plays no role in mediating any dynamics of cardiovascular synchronization in the studied frequency range. When comparing these results with those in mammals, a lesser overall autonomic involvement in the mediation of the studied cardiovascular interdependences is seen in reptiles.
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Affiliation(s)
- Luis De Vera
- Laboratory of Biophysics, Department of Physiology, University of La Laguna, 38071-La Laguna, Tenerife, Canary Islands, Spain
| | - Rubén V. Rial
- Institut Universitari de Ciencies de la Salut, Universitat de les Illes Balears, 07071-Palma de Mallorca, Mallorca, Illes Balears, Spain
| | - Ernesto Pereda
- Electrical Engineering and Bioengineering Group, Department of Basic Physics, University of La Laguna, 38206-La Laguna, Tenerife, Canary Islands, Spain
| | - Julián J. González
- Laboratory of Biophysics, Department of Physiology, University of La Laguna, 38071-La Laguna, Tenerife, Canary Islands, Spain
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19
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Taylor E, Leite C, Skovgaard N. Autonomic control of cardiorespiratory interactions in fish, amphibians and reptiles. Braz J Med Biol Res 2010; 43:600-10. [DOI: 10.1590/s0100-879x2010007500044] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2010] [Accepted: 04/27/2010] [Indexed: 11/22/2022] Open
Affiliation(s)
- E.W. Taylor
- University of Birmingham, UK; Universidade Estadual Paulista, Brasil; Instituto Nacional de Ciência e Tecnologia em Fisiologia Comparada, Brasil
| | - C.A.C. Leite
- Universidade Estadual Paulista, Brasil; Instituto Nacional de Ciência e Tecnologia em Fisiologia Comparada, Brasil
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20
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Leite CAC, Taylor EW, Guerra CDR, Florindo LH, Belão T, Rantin FT. The role of the vagus nerve in the generation of cardiorespiratory interactions in a neotropical fish, the pacu, Piaractus mesopotamicus. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2009; 195:721-31. [DOI: 10.1007/s00359-009-0447-2] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2008] [Revised: 04/16/2009] [Accepted: 04/19/2009] [Indexed: 11/28/2022]
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21
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Grossman P, Taylor EW. Toward understanding respiratory sinus arrhythmia: relations to cardiac vagal tone, evolution and biobehavioral functions. Biol Psychol 2006; 74:263-85. [PMID: 17081672 DOI: 10.1016/j.biopsycho.2005.11.014] [Citation(s) in RCA: 678] [Impact Index Per Article: 37.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/16/2005] [Indexed: 11/16/2022]
Abstract
Respiratory sinus arrhythmia (RSA, or high-frequency heart-rate variability) is frequently employed as an index of cardiac vagal tone or even believed to be a direct measure of vagal tone. However, there are many significant caveats regarding vagal tone interpretation: 1. Respiratory parameters can confound relations between RSA and cardiac vagal tone.2. Although intraindividual relations between RSA and cardiac vagal control are often strong, interindividual associations may be modest.3. RSA measurement is profoundly influenced by concurrent levels of momentary physical activity, which can bias estimation of individual differences in vagal tone.4. RSA magnitude is affected by beta-adrenergic tone.5. RSA and cardiac vagal tone can dissociate under certain circumstances.6. The polyvagal theory contains evolution-based speculations that relate RSA, vagal tone and behavioral phenomena. We present evidence that the polyvagal theory does not accurately depict evolution of vagal control of heart-rate variability, and that it ignores the phenomenon of cardiac aliasing and disregards the evolution of a functional role for vagal control of the heart, from cardiorespiratory synchrony in fish to RSA in mammals. Unawareness of these issues can lead to misinterpretation of cardiovascular autonomic mechanisms. On the other hand, RSA has been shown to often provide a reasonable reflection of cardiac vagal tone when the above-mentioned complexities are considered. Finally, a recent hypothesis is expanded upon, in which RSA plays a primary role in regulation of energy exchange by means of synchronizing respiratory and cardiovascular processes during metabolic and behavioral change.
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Affiliation(s)
- Paul Grossman
- Department of Psychosomatic and Internal Medicine, Psychophysiology Research Laboratory, University of Basel Hospital, Hebelstrasse 2, CH-4031 Basel, Switzerland.
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22
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Porges SW. A phylogenetic journey through the vague and ambiguous Xth cranial nerve: a commentary on contemporary heart rate variability research. Biol Psychol 2006; 74:301-7. [PMID: 17055142 PMCID: PMC1828879 DOI: 10.1016/j.biopsycho.2006.08.007] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/14/2006] [Indexed: 10/24/2022]
Abstract
Contemporary heart rate variability research is discussed within a historical context. Implicit in this history is the discovery that the central nervous system regulates the heart and how information regarding neural regulation of the heart is imbedded in the beat-to-beat heart rate pattern. As methodologies have become more sensitive to neural regulation and as theories have expanded to integrate behavior and psychological processes with neurobiological principles, researchers are becoming better positioned to successfully understand how neurovisceral processes mediate the expression of health and disease. The contributions to this special issue describe research representing different levels of scientific inquiry and focus on different features of the complex neural feedback system that are manifested in the robust relationships between heart rate variability and several behavioral, psychological, physiological, and health processes. This article provides a commentary to these contributions.
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Affiliation(s)
- Stephen W Porges
- University of Illinois at Chicago, Brain-Body Center, Department of Psychiatry, Chicago, IL 60612, USA.
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23
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Campbell HA, Leite CAC, Wang T, Skals M, Abe AS, Egginton S, Rantin FT, Bishop CM, Taylor EW. Evidence for a respiratory component, similar to mammalian respiratory sinus arrhythmia, in the heart rate variability signal from the rattlesnake,Crotalus durissus terrificus. J Exp Biol 2006; 209:2628-36. [PMID: 16809454 DOI: 10.1242/jeb.02278] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
SUMMARYAutonomic control of heart rate variability and the central location of vagal preganglionic neurones (VPN) were examined in the rattlesnake(Crotalus durissus terrificus), in order to determine whether respiratory sinus arrhythmia (RSA) occurred in a similar manner to that described for mammals. Resting ECG signals were recorded in undisturbed snakes using miniature datalogging devices, and the presence of oscillations in heart rate (fh) was assessed by power spectral analysis (PSA). This mathematical technique provides a graphical output that enables the estimation of cardiac autonomic control by measuring periodic changes in the heart beat interval. At fh above 19 min-1spectra were mainly characterised by low frequency components, reflecting mainly adrenergic tonus on the heart. By contrast, at fhbelow 19 min-1 spectra typically contained high frequency components, demonstrated to be cholinergic in origin. Snakes with a fh >19 min-1 may therefore have insufficient cholinergic tonus and/or too high an adrenergic tonus acting upon the heart for respiratory sinus arrhythmia (RSA) to develop. A parallel study monitored fh simultaneously with the intraperitoneal pressures associated with lung inflation. Snakes with a fh<19 min-1 exhibited a high frequency (HF) peak in the power spectrum,which correlated with ventilation rate (fv). Adrenergic blockade by propranolol infusion increased the variability of the ventilation cycle, and the oscillatory component of the fh spectrum broadened accordingly. Infusion of atropine to effect cholinergic blockade abolished this HF component, confirming a role for vagal control of the heart in matching fh and fv in the rattlesnake. A neuroanatomical study of the brainstem revealed two locations for vagal preganglionic neurones (VPN). This is consistent with the suggestion that generation of ventilatory components in the heart rate variability (HRV)signal are dependent on spatially distinct loci for cardiac VPN. Therefore,this study has demonstrated the presence of RSA in the HRV signal and a dual location for VPN in the rattlesnake. We suggest there to be a causal relationship between these two observations.
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24
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The Cardiorespiratory System in Tropical Fishes: Structure, Function, and Control. ACTA ACUST UNITED AC 2005. [DOI: 10.1016/s1546-5098(05)21006-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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25
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Lancien F, Leprince J, Mimassi N, Mabin D, Vaudry H, Le Mével JC. Central effects of native urotensin II on motor activity, ventilatory movements, and heart rate in the trout Oncorhynchus mykiss. Brain Res 2004; 1023:167-74. [PMID: 15374742 DOI: 10.1016/j.brainres.2004.07.008] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2004] [Indexed: 02/07/2023]
Abstract
Urotensin II (UII) has been originally isolated from fish urophysis. However, in fish as in mammals, UII is also produced in brain neurons. Although UII binding sites are widely distributed in the fish central nervous system (CNS), little is known regarding its central activities. In the present study, we have investigated the effects of intracerebroventricular (ICV) administration of synthetic trout UII on the duration of motor activity (ACT; evidenced by bursts of activity on the trace of the ventilatory signal), ventilatory frequency (VF), ventilatory amplitude (VA), and heart rate (HR) in unanesthesized trout, Oncorhynchus mykiss. ICV injection of very low doses of UII (1 and 5 pmol) produced a dose-dependent increase of ACT without affecting VF, VA, or HR. At a higher dose (50 pmol), UII stimulated ACT as well as VF, VA, and HR. ICV injection of trout angiotensin II (5 pmol) did not affect ACT, VF, and VA, but provoked a robust increase in HR. These data provide the first evidence that central administration of UII stimulates motor activity in a nonmammalian vertebrate.
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Affiliation(s)
- Frédéric Lancien
- Laboratoire de Traitement de l'Information Médicale, INSERM U650, EA 2218, Faculté de Médecine et des Sciences de la Santé, Université de Bretagne Occidentale, Brest Cedex 3 29238, France
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26
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Verklan MT, Padhye NS. Spectral Analysis of Heart Rate Variability: An Emerging Tool for Assessing Stability During Transition to Extrauterine Life. J Obstet Gynecol Neonatal Nurs 2004; 33:256-65. [PMID: 15095805 DOI: 10.1177/0884217504263301] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
Transition from fetal to neonatal life is likely the most physiologically demanding time of life. Complex changes in major organ system functioning and reorganization of metabolic processes must occur rapidly to achieve postnatal homeostasis. Identifying the neonate with subtle signs of unsuccessful transition is a challenge to the perinatal health care provider. Alterations in fetal or neonatal heart rate and heart rate variability may serve as an indicator of the neural control influencing cardiac function and a sensitive indicator of compromised health. Evaluation of the neural control of the heart can be done noninvasively and provides a discriminating measure of the level of stress vulnerability the fetus or newborn may be experiencing. This article reviews the origins of physiological variability of the fetal and neonatal heart rate in the transition to extrauterine life. The technique of spectral analysis as a new tool for surveillance of the at-risk fetus and neonate is then introduced, and implications for clinical practice and future research avenues are discussed.
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Affiliation(s)
- M Terese Verklan
- University of Texas Health Science Center at Houston, School of Nursing, 77030, USA.
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27
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Wang T, Warburton S, Abe A, Taylor T. Vagal control of heart rate and cardiac shunts in reptiles: relation to metabolic state. Exp Physiol 2001; 86:777-84. [PMID: 11698973 DOI: 10.1111/j.1469-445x.2001.tb00044.x] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- T Wang
- Zoofysiologisk Afdeling, Aarhus Universitet, Universitetsparken, 8000 Aarhus C, Denmark.
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