1
|
Burman R, Alperin N. CSF-to-blood toxins clearance is modulated by breathing through cranio-spinal CSF oscillation. J Sleep Res 2024; 33:e14029. [PMID: 37734843 DOI: 10.1111/jsr.14029] [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: 05/18/2023] [Revised: 07/14/2023] [Accepted: 08/16/2023] [Indexed: 09/23/2023]
Abstract
Clearance of brain toxins occurs during sleep, although the mechanism remains unknown. Previous studies implied that the intracranial aqueductal cerebrospinal fluid (CSF) oscillations are involved, but no mechanism was suggested. The rationale for focusing on the aqueductal CSF oscillations is unclear. This study focuses on the cranio-spinal CSF oscillation and the factors that modulate this flow. We propose a mechanism where increased cranio-spinal CSF movements enhance CSF-to-blood metabolic waste clearance through the spinal CSF re-absorption sites. A recent study demonstrating that disturbed sleep impairs CSF-to-blood but not brain-to-CSF clearance, supports the fundamentals of our proposed mechanism. Eight healthy subjects underwent phase-contrast magnetic resonance imaging to quantify the effect of respiration on the cranio-spinal CSF oscillations. Maximal CSF volume displaced from the cranium to the spinal canal during each respiration and cardiac cycle were derived as measures of cranio-spinal CSF mixing level. Transition from normal to slow and abdominal breathing resulted in a 56% increase in the maximal displaced CSF volume. Maximal change in the arterial-venous blood volume, which is the driving force of the CSF oscillations, was increased by 41% during slow abdominal breathing. Cranio-spinal CSF oscillations are driven by the momentary difference between arterial inflow and venous outflow. Breathing modulates the CSF oscillation through changes in the venous outflow. The amount of toxins being transferred to the spinal canal during each respiratory cycle is significantly increased during slow and deeper abdominal breathing, which explains enhanced CSF-to-blood toxins clearance during slow-wave sleep and poor clearance during disrupted sleep.
Collapse
Affiliation(s)
- Ritambhar Burman
- Department of Biomedical Engineering, University of Miami, Miami, Florida, USA
| | - Noam Alperin
- Department of Biomedical Engineering, University of Miami, Miami, Florida, USA
- Department of Radiology, Miller School of Medicine, University of Miami, Miami, Florida, USA
| |
Collapse
|
2
|
Ritz T. Putting back respiration into respiratory sinus arrhythmia or high-frequency heart rate variability: Implications for interpretation, respiratory rhythmicity, and health. Biol Psychol 2024; 185:108728. [PMID: 38092221 DOI: 10.1016/j.biopsycho.2023.108728] [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: 06/26/2022] [Revised: 12/06/2023] [Accepted: 12/07/2023] [Indexed: 12/23/2023]
Abstract
Research on respiratory sinus arrhythmia, or high-frequency heart rate variability (its frequency-domain equivalent), has been popular in psychology and the behavioral sciences for some time. It is typically interpreted as an indicator of cardiac vagal activity. However, as research has shown for decades, the respiratory pattern can influence the amplitude of these noninvasive measures substantially, without necessarily reflecting changes in tonic cardiac vagal activity. Although changes in respiration are systematically associated with experiential and behavioral states, this potential confound in the interpretation of RSA, or HF-HRV, is rarely considered. Interpretations of within-individual changes in these parameters are therefore only conclusive if undertaken relative to the breathing pattern. The interpretation of absolute levels of these parameters between individuals is additionally burdened with the problem of residual inspiratory cardiac vagal activity in humans. Furthermore, multiple demographic, anthropometric, life-style, health, and medication variables can act as relevant third variables that might explain associations of RSA or HF-HRV with experiential and behavioral variables. Because vagal activity measured by these parameters only represents the portion of cardiac vagal outflow that is modulated by the respiratory rhythm, alternative interpretations beyond cardiac vagal activity should be considered. Accumulating research shows that activity of multiple populations of neurons in the brain and the periphery, and with that organ activity and function, are modulated rhythmically by respiratory activity. Thus, observable health benefits ascribed to the cardiac vagal system through RSA or HF-HRV may actually reflect beneficial effects of respiratory modulation. Respiratory rhythmicity may ultimately provide the mechanism that integrates central, autonomic, and visceral activities.
Collapse
Affiliation(s)
- Thomas Ritz
- Department of Psychology, Southern Methodist University, Dallas, TX, USA.
| |
Collapse
|
3
|
Woo JY, Pikov V, Chen JD. Neuromodulation for Gastroesophageal Reflux Disease: A Systematic Review. JOURNAL OF TRANSLATIONAL GASTROENTEROLOGY 2023; 1:47-56. [PMID: 38009094 PMCID: PMC10673618] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 11/28/2023]
Abstract
Background and objectives In this systematic review, we evaluated the efficacy, mechanisms and safety of three neuromodulation therapies in patients with gastroesophageal reflux disease (GERD), including the effect of neuromodulation therapies on symptoms and key GERD pathophysiologies, lower esophageal sphincter (LES) pressure, esophageal motility, gastric motility, and parasympathetic activity. The first therapy is LES electrical stimulation using an implantable electrical stimulator, the second is transcutaneous electrical acustimulation, and the third is manual acupuncture. Methods A systematic review of literature according to the PRISMA guidelines was performed. Online databases searched include Medline (Ovid), Embase, and PubMed. Studies were assessed for inclusion and exclusion criteria with Covidence, a systematic review software. Results The analysis included thirteen clinical studies. Four papers included were registered under two open-label trials on ClinicalTrials.gov for LES electrical stimulation; Five randomized trials with sham-treated controls were analyzed for transcutaneous electrical acustimulation; Four studies, including three involving standard therapy controls and one involving shamtreated controls were included for manual acupuncture. All evaluated studies demonstrated significant beneficial effects on GERD symptoms, using patient-completed questionnaires, objective 24-h measurement of esophageal pH, and patient-reported use of proton pump inhibitors. In evaluating the effect on key GERD pathophysiologies, electrical stimulation significantly increased LES pressure, and transcutaneous electrical acustimulation significantly improved esophageal motility, gastric motility, and parasympathetic activity. None of the evaluated neuromodulation methods produced severe adverse effects. Conclusions Cumulative evidence from the evaluated studies indicates that neuromodulation therapies were effective in treating the GERD symptoms and key underlying GERD pathophysiologies. They are thus valuable options for individualized GERD treatment.
Collapse
Affiliation(s)
- Jia Yi Woo
- Northern Health, Epping, Victoria, Australia
| | | | - Jiande D.Z. Chen
- Division of Gastroenterology and Hepatology, University of Michigan School of Medicine, Ann Arbor, MI, USA
| |
Collapse
|
4
|
Pingali H, Hunter SD. Exploring mechanisms of blood pressure regulation in response to device-guided and non-device-guided slow breathing: A mini review. Auton Neurosci 2023; 244:103050. [PMID: 36410208 DOI: 10.1016/j.autneu.2022.103050] [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: 06/27/2022] [Revised: 11/08/2022] [Accepted: 11/09/2022] [Indexed: 11/16/2022]
Abstract
BACKGROUND Hypertension is a widespread disease that, if persistent, increases the risks of coronary heart disease mortality and morbidity. Slow breathing is a recommended blood pressure-lowering strategy though the mechanisms mediating its effects are unknown. OBJECTIVE This review aims to evaluate autonomic and vascular function as potential mediators driving BP adaptive responses with slow breathing. METHODS We searched EBSCO host, Web of Science, Cochrane Central Register of Controlled Trials, and PubMed using key words for optimized search results. RESULTS Nineteen studies were included in this review (11 device-guided; 8 non-device-guided breathing). Though some studies showed increased vagally mediated components of heart rate variability during slow breathing, results from acute and long-term studies were incongruent. Increases in baroreflex sensitivity (BRS) following a single device-guided slow breathing bout were noted in normotensive and hypertensive adults. Long-term (4 weeks to 3 months) effects of slow breathing on BRS were absent. Device-guided breathing resulted in immediate reductions in muscle sympathetic nerve activity (MSNA) in normo- and hyper-tensive adults though results from long-term studies yielded inconsistent findings. Non-device-guided slow breathing posed acute and chronic effects on vascular function with reductions in arterial stiffness in adults with type I diabetes and increases in microvascular endothelial function in adults with irritable bowel syndrome. Non-device guided breathing also reduced pro-inflammatory cytokines in healthy and hypertensive adults in acute and chronic studies. No adverse effects or non-adherence to treatment were noted in these trials. CONCLUSION Device-guided slow breathing is a feasible and effective modality in improving BRS, HRV, and arterial stiffness though its long-term effects are obscure. Though less evidence exists supporting the efficacy of non-device-guided slow breathing, acute and chronic studies demonstrate improvements in vascular function and inflammatory cytokines. More studies are needed to further explore the long-term effects of slow breathing in general and non-device-guided breathing in particular.
Collapse
Affiliation(s)
- Harika Pingali
- Texas State University Department of Health & Human Performance, San Marcos, TX, USA
| | - Stacy D Hunter
- Texas State University Department of Health & Human Performance, San Marcos, TX, USA.
| |
Collapse
|
5
|
Merabet N, Lucassen PJ, Crielaard L, Stronks K, Quax R, Sloot PMA, la Fleur SE, Nicolaou M. How exposure to chronic stress contributes to the development of type 2 diabetes: A complexity science approach. Front Neuroendocrinol 2022; 65:100972. [PMID: 34929260 DOI: 10.1016/j.yfrne.2021.100972] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2021] [Revised: 11/24/2021] [Accepted: 12/12/2021] [Indexed: 11/18/2022]
Abstract
Chronic stress contributes to the onset of type 2 diabetes (T2D), yet the underlying etiological mechanisms are not fully understood. Responses to stress are influenced by earlier experiences, sex, emotions and cognition, and involve a complex network of neurotransmitters and hormones, that affect multiple biological systems. In addition, the systems activated by stress can be altered by behavioral, metabolic and environmental factors. The impact of stress on metabolic health can thus be considered an emergent process, involving different types of interactions between multiple variables, that are driven by non-linear dynamics at different spatiotemporal scales. To obtain a more comprehensive picture of the links between chronic stress and T2D, we followed a complexity science approach to build a causal loop diagram (CLD) connecting the various mediators and processes involved in stress responses relevant for T2D pathogenesis. This CLD could help develop novel computational models and formulate new hypotheses regarding disease etiology.
Collapse
Affiliation(s)
- Nadège Merabet
- Department of Public and Occupational Health, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research Institute, Meibergdreef 9, Amsterdam, the Netherlands; Institute for Advanced Study, University of Amsterdam, Amsterdam 1012 GC, the Netherlands; Centre for Urban Mental Health, University of Amsterdam, Amsterdam 1012 GC, the Netherlands
| | - Paul J Lucassen
- Centre for Urban Mental Health, University of Amsterdam, Amsterdam 1012 GC, the Netherlands; Brain Plasticity Group, Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam 1098 XH, the Netherlands
| | - Loes Crielaard
- Department of Public and Occupational Health, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research Institute, Meibergdreef 9, Amsterdam, the Netherlands; Institute for Advanced Study, University of Amsterdam, Amsterdam 1012 GC, the Netherlands
| | - Karien Stronks
- Department of Public and Occupational Health, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research Institute, Meibergdreef 9, Amsterdam, the Netherlands; Institute for Advanced Study, University of Amsterdam, Amsterdam 1012 GC, the Netherlands; Centre for Urban Mental Health, University of Amsterdam, Amsterdam 1012 GC, the Netherlands
| | - Rick Quax
- Institute for Advanced Study, University of Amsterdam, Amsterdam 1012 GC, the Netherlands; Computational Science Lab, University of Amsterdam, Amsterdam 1098 XH, the Netherlands
| | - Peter M A Sloot
- Institute for Advanced Study, University of Amsterdam, Amsterdam 1012 GC, the Netherlands; Centre for Urban Mental Health, University of Amsterdam, Amsterdam 1012 GC, the Netherlands; Computational Science Lab, University of Amsterdam, Amsterdam 1098 XH, the Netherlands; National Centre of Cognitive Research, ITMO University, St. Petersburg, Russian Federation
| | - Susanne E la Fleur
- Department of Endocrinology and Metabolism & Laboratory of Endocrinology, Department of Clinical Chemistry, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, the Netherlands; Metabolism and Reward Group, Netherlands Institute for Neuroscience, an Institute of the Royal Netherlands Academy of Arts and Sciences, Meibergdreef 47, Amsterdam, the Netherlands.
| | - Mary Nicolaou
- Department of Public and Occupational Health, Amsterdam UMC, University of Amsterdam, Amsterdam Public Health Research Institute, Meibergdreef 9, Amsterdam, the Netherlands; Institute for Advanced Study, University of Amsterdam, Amsterdam 1012 GC, the Netherlands; Centre for Urban Mental Health, University of Amsterdam, Amsterdam 1012 GC, the Netherlands.
| |
Collapse
|