1
|
Mehta RI, Mehta RI. Understanding central nervous system fluid networks: Historical perspectives and a revised model for clinical neurofluid imaging. NMR IN BIOMEDICINE 2024; 37:e5149. [PMID: 38584002 DOI: 10.1002/nbm.5149] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2023] [Revised: 02/26/2024] [Accepted: 02/27/2024] [Indexed: 04/09/2024]
Abstract
The central nervous system (CNS) lacks traditionally defined lymphatic vasculature. However, CNS tissues and barriers compartmentalize the brain, spinal cord, and adjacent spaces, facilitating the transmittal of fluids, metabolic wastes, immune cells, and vital signals, while more conventional lymphatic pathways in the meninges, cervicofacial and paraspinal regions transmit efflux fluid and molecules to peripheral lymph and lymph nodes. Thus, a unique and highly organized fluid circulation network encompassing intraparenchymal, subarachnoid, dural, and extradural segments functions in unison to maintain CNS homeostasis. Pathways involved in this system have been under investigation for centuries and continue to be the source of considerable interest and debate. Modern imaging and microscopy technologies have led to important breakthroughs pertaining to various elements of CNS fluid circuitry and exchange over the past decade, thus enhancing knowledge on mechanisms of mammalian CNS maintenance and disease. Yet, to better understand precise anatomical routes, the physiology and clinical significance of these CNS pathways, and potential therapeutic targets in humans, fluid conduits, flow-regulating factors, and tissue effects must be analyzed systematically and in a global manner in persons across age, demographical factors, and disease states. Here, we illustrate the system-wide nature of intermixing CNS fluid networks, summarize historical and clinical studies, and discuss anatomical and physiological similarities and differences that are relevant for translation of evidence from mice to humans. We also review Cushing's classical model of cerebrospinal fluid flow and present a new framework of this "third circulation" that emphasizes previously unexplained complexities of CNS fluid circulation in humans. Finally, we review future directions in the field, including emerging theranostic techniques and MRI studies required in humans.
Collapse
Affiliation(s)
- Rupal I Mehta
- Department of Pathology, Rush University Medical Center, Chicago, Illinois, USA
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, Illinois, USA
| | - Rashi I Mehta
- Department of Neuroradiology, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
- Department of Neuroscience, Rockefeller Neuroscience Institute, West Virginia University, Morgantown, West Virginia, USA
| |
Collapse
|
2
|
Yue Y, Zhang X, Lv W, Lai HY, Shen T. Interplay between the glymphatic system and neurotoxic proteins in Parkinson's disease and related disorders: current knowledge and future directions. Neural Regen Res 2024; 19:1973-1980. [PMID: 38227524 DOI: 10.4103/1673-5374.390970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 10/26/2023] [Indexed: 01/17/2024] Open
Abstract
Parkinson's disease is a common neurodegenerative disorder that is associated with abnormal aggregation and accumulation of neurotoxic proteins, including α-synuclein, amyloid-β, and tau, in addition to the impaired elimination of these neurotoxic protein. Atypical parkinsonism, which has the same clinical presentation and neuropathology as Parkinson's disease, expands the disease landscape within the continuum of Parkinson's disease and related disorders. The glymphatic system is a waste clearance system in the brain, which is responsible for eliminating the neurotoxic proteins from the interstitial fluid. Impairment of the glymphatic system has been proposed as a significant contributor to the development and progression of neurodegenerative disease, as it exacerbates the aggregation of neurotoxic proteins and deteriorates neuronal damage. Therefore, impairment of the glymphatic system could be considered as the final common pathway to neurodegeneration. Previous evidence has provided initial insights into the potential effect of the impaired glymphatic system on Parkinson's disease and related disorders; however, many unanswered questions remain. This review aims to provide a comprehensive summary of the growing literature on the glymphatic system in Parkinson's disease and related disorders. The focus of this review is on identifying the manifestations and mechanisms of interplay between the glymphatic system and neurotoxic proteins, including loss of polarization of aquaporin-4 in astrocytic endfeet, sleep and circadian rhythms, neuroinflammation, astrogliosis, and gliosis. This review further delves into the underlying pathophysiology of the glymphatic system in Parkinson's disease and related disorders, and the potential implications of targeting the glymphatic system as a novel and promising therapeutic strategy.
Collapse
Affiliation(s)
- Yumei Yue
- Department of Neurology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Xiaodan Zhang
- Department of Emergency Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China
| | - Wen Lv
- Department of Neurology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Hsin-Yi Lai
- Department of Neurology of the Second Affiliated Hospital and School of Brain Science and Brain Medicine, Interdisciplinary Institute of Neuroscience and Technology, Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
- College of Biomedical Engineering and Instrument Science, Zhejiang University, Hangzhou, Zhejiang Province, China
- MOE Frontier Science Center for Brain Science and Brain-Machine Integration, State Key Laboratory of Brain-machine Intelligence, School of Brain Science and Brain Medicine, Zhejiang University, Hangzhou, Zhejiang Province, China
| | - Ting Shen
- Department of Neurology of the Second Affiliated Hospital and School of Brain Science and Brain Medicine, Interdisciplinary Institute of Neuroscience and Technology, Key Laboratory of Medical Neurobiology of Zhejiang Province, Zhejiang University School of Medicine, Hangzhou, Zhejiang Province, China
| |
Collapse
|
3
|
Peng W, Yuan Y, Lei J, Zhao Y, Li Y, Qu Q, Wang J. Long-Term High-Fat Diet Impairs AQP4-Mediated Glymphatic Clearance of Amyloid Beta. Mol Neurobiol 2024:10.1007/s12035-024-04320-3. [PMID: 38958889 DOI: 10.1007/s12035-024-04320-3] [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: 03/04/2024] [Accepted: 06/19/2024] [Indexed: 07/04/2024]
Abstract
As a risk factor for Alzheimer's disease (AD), studies have demonstrated that long-term high-fat diet (HFD) could accelerate the deposition of amyloid beta (Aβ) in the brain. The glymphatic system plays a critical role in Aβ clearance from the brain. However, studies investigating the effects of long-term HFD on glymphatic function have reported paradoxical outcomes, and whether glymphatic dysfunction is involved in the disturbance of Aβ clearance in long-term HFD-fed mice has not been determined. In the present study, we injected fluorescently labeled Aβ into the hippocampus and found that Aβ clearance was decreased in HFD-fed mice. We found that long-term HFD-fed mice had decreased glymphatic function by injecting fluorescent tracers into the cisterna magna and corpus striatum. In long-term HFD-fed mice, aquaporin-4 (AQP4) polarization in the cortex was disrupted, and glymphatic clearance activity was positively correlated with the AQP4 polarization index. In HFD-fed mice, the disturbance of Aβ clearance from the hippocampus was exacerbated by TGN-020, a specific inhibitor of AQP4, whereas TGN-073, an enhancer of AQP4, ameliorated it. These findings suggest that long-term HFD disrupts Aβ clearance by inhibiting AQP4-mediated glymphatic function. The underlying mechanism may involve the disruption of AQP4 polarization.
Collapse
Affiliation(s)
- Wei Peng
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Rd, Xi'an, 710061, China
| | - Ye Yuan
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Rd, Xi'an, 710061, China
| | - Jingna Lei
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Rd, Xi'an, 710061, China
| | - Yi Zhao
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Rd, Xi'an, 710061, China
| | - Yan Li
- Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China
| | - Qiumin Qu
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Rd, Xi'an, 710061, China.
- Center for Brain Science, The First Affiliated Hospital of Xi'an Jiaotong University, Xi'an, China.
| | - Jin Wang
- Department of Neurology, The First Affiliated Hospital of Xi'an Jiaotong University, 277 West Yanta Rd, Xi'an, 710061, China.
| |
Collapse
|
4
|
Smets NG, Strijkers GJ, Vinje V, Bakker ENTP. Cerebrospinal fluid turnover as a driver of brain clearance. NMR IN BIOMEDICINE 2024; 37:e5029. [PMID: 37658736 DOI: 10.1002/nbm.5029] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/30/2023] [Accepted: 08/05/2023] [Indexed: 09/05/2023]
Abstract
Cerebrospinal fluid (CSF) has historically been considered to function as a sink for brain-derived waste disposal. Recent work suggested that CSF interacts even more intensely with brain tissue than previously recognized, through perivascular spaces that penetrate the brain. Cardiac pulsations, vasomotion, and respiration have been suggested to drive CSF flow in these perivascular spaces, thereby enhancing waste clearance. However, the intrinsic role of CSF production in relation to its distribution volume (turnover) is not an explicit component of recent concepts on brain clearance. Here, we review the work on CSF turnover and volume, focusing on preclinical evidence. Herein, we highlight the use of MRI in establishing CSF-related parameters. We describe the impact of sleep, effect of anesthesia, aging, and hypertension on CSF turnover, and how this relates to brain clearance. Evaluation of the available evidence suggests that CSF turnover is a major determinant in brain clearance. In addition, we propose that several putative drivers of brain clearance, but also conditions associated with impaired clearance, such as aging, may actually relate to altered CSF turnover.
Collapse
Affiliation(s)
- Nina G Smets
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, location AMC, Amsterdam, the Netherlands
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, the Netherlands
- Amsterdam Neuroscience Research Institute, Amsterdam, the Netherlands
| | - Gustav J Strijkers
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, location AMC, Amsterdam, the Netherlands
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, the Netherlands
| | | | - Erik N T P Bakker
- Department of Biomedical Engineering and Physics, Amsterdam University Medical Center, location AMC, Amsterdam, the Netherlands
- Amsterdam Cardiovascular Sciences Research Institute, Amsterdam, the Netherlands
- Amsterdam Neuroscience Research Institute, Amsterdam, the Netherlands
| |
Collapse
|
5
|
Yoon SH, Kim YC, Seo HJ, Hong SC, Kim TW, Jeong JH, Um YH. Association Between Hypnotics and Dementia: A Mini Narrative Review. Psychiatry Investig 2024; 21:457-463. [PMID: 38810994 PMCID: PMC11136580 DOI: 10.30773/pi.2023.0383] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Revised: 02/22/2024] [Accepted: 03/16/2024] [Indexed: 05/31/2024] Open
Abstract
OBJECTIVE This narrative review aims to provide a comprehensive assessment of the existing literature on the relationship between hypnotics and dementia, considering both potential link and inconclusive or lack of association. METHODS Data from studies that investigate the association between hypnotic medications and dementia were reviewed. Studies included both cohort studies and systematic reviews, participants with various type of dementia and hypnotics including benzodiazepines (BZDs) and Z-drugs (ZDs). RESULTS The existing literatures presents conflicting evidence regarding the association between hypnotics, including BZDs and ZDs, and the risk of dementia. Some studies suggest a potential link between prolonged use of hypnotics and an increased risk of dementia. However, other studies indicate inconclusive or lacking evidence regarding this association. Factors such as study design, sample characteristics, and control of confounding variables contribute to the variability in findings. CONCLUSION The relationship between hypnotics and dementia remains complex and controversial. While some studies suggest a potential association, others find inconclusive or conflicting evidence. Future research should focus on addressing methodological limitations, considering classifying dementia subtypes, and try to adjust medication lag time.
Collapse
Affiliation(s)
- Sung-Hoon Yoon
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Psychiatry, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea
| | - Young-Chan Kim
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Psychiatry, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea
| | - Ho Jun Seo
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Psychiatry, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea
| | - Seung Chul Hong
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Psychiatry, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea
| | - Tae Won Kim
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Psychiatry, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea
| | - Jong-Hyun Jeong
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Psychiatry, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea
| | - Yoo Hyun Um
- Department of Psychiatry, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
- Department of Psychiatry, St. Vincent’s Hospital, College of Medicine, The Catholic University of Korea, Suwon, Republic of Korea
| |
Collapse
|
6
|
Rae CD, Baur JA, Borges K, Dienel G, Díaz-García CM, Douglass SR, Drew K, Duarte JMN, Duran J, Kann O, Kristian T, Lee-Liu D, Lindquist BE, McNay EC, Robinson MB, Rothman DL, Rowlands BD, Ryan TA, Scafidi J, Scafidi S, Shuttleworth CW, Swanson RA, Uruk G, Vardjan N, Zorec R, McKenna MC. Brain energy metabolism: A roadmap for future research. J Neurochem 2024; 168:910-954. [PMID: 38183680 PMCID: PMC11102343 DOI: 10.1111/jnc.16032] [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: 05/27/2023] [Revised: 11/29/2023] [Accepted: 12/05/2023] [Indexed: 01/08/2024]
Abstract
Although we have learned much about how the brain fuels its functions over the last decades, there remains much still to discover in an organ that is so complex. This article lays out major gaps in our knowledge of interrelationships between brain metabolism and brain function, including biochemical, cellular, and subcellular aspects of functional metabolism and its imaging in adult brain, as well as during development, aging, and disease. The focus is on unknowns in metabolism of major brain substrates and associated transporters, the roles of insulin and of lipid droplets, the emerging role of metabolism in microglia, mysteries about the major brain cofactor and signaling molecule NAD+, as well as unsolved problems underlying brain metabolism in pathologies such as traumatic brain injury, epilepsy, and metabolic downregulation during hibernation. It describes our current level of understanding of these facets of brain energy metabolism as well as a roadmap for future research.
Collapse
Affiliation(s)
- Caroline D. Rae
- School of Psychology, The University of New South Wales, NSW 2052 & Neuroscience Research Australia, Randwick, New South Wales, Australia
| | - Joseph A. Baur
- Department of Physiology and Institute for Diabetes, Obesity and Metabolism, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Karin Borges
- School of Biomedical Sciences, Faculty of Medicine, The University of Queensland, St Lucia, QLD, Australia
| | - Gerald Dienel
- Department of Neurology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
- Department of Cell Biology and Physiology, University of New Mexico School of Medicine, Albuquerque, New Mexico, USA
| | - Carlos Manlio Díaz-García
- Department of Biochemistry and Molecular Biology, Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma, USA
| | | | - Kelly Drew
- Center for Transformative Research in Metabolism, Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, Alaska, USA
| | - João M. N. Duarte
- Department of Experimental Medical Science, Faculty of Medicine, Lund University, Lund, & Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Jordi Duran
- Institut Químic de Sarrià (IQS), Universitat Ramon Llull (URL), Barcelona, Spain
- Institute for Bioengineering of Catalonia (IBEC), The Barcelona Institute of Science and Technology, Barcelona, Spain
| | - Oliver Kann
- Institute of Physiology and Pathophysiology, University of Heidelberg, D-69120; Interdisciplinary Center for Neurosciences (IZN), University of Heidelberg, Heidelberg, Germany
| | - Tibor Kristian
- Veterans Affairs Maryland Health Center System, Baltimore, Maryland, USA
- Department of Anesthesiology and the Center for Shock, Trauma, and Anesthesiology Research (S.T.A.R.), University of Maryland School of Medicine, Baltimore, Maryland, USA
| | - Dasfne Lee-Liu
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Santiago, Región Metropolitana, Chile
| | - Britta E. Lindquist
- Department of Neurology, Division of Neurocritical Care, Gladstone Institute of Neurological Disease, University of California at San Francisco, San Francisco, California, USA
| | - Ewan C. McNay
- Behavioral Neuroscience, University at Albany, Albany, New York, USA
| | - Michael B. Robinson
- Departments of Pediatrics and System Pharmacology & Translational Therapeutics, Children’s Hospital of Philadelphia, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Douglas L. Rothman
- Magnetic Resonance Research Center and Departments of Radiology and Biomedical Engineering, Yale University, New Haven, Connecticut, USA
| | - Benjamin D. Rowlands
- School of Chemistry, Faculty of Science, The University of Sydney, Sydney, New South Wales, Australia
| | - Timothy A. Ryan
- Department of Biochemistry, Weill Cornell Medicine, New York, New York, USA
| | - Joseph Scafidi
- Department of Neurology, Kennedy Krieger Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Susanna Scafidi
- Anesthesiology & Critical Care Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - C. William Shuttleworth
- Department of Neurosciences, University of New Mexico School of Medicine Albuquerque, Albuquerque, New Mexico, USA
| | - Raymond A. Swanson
- Department of Neurology, University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Gökhan Uruk
- Department of Neurology, University of California, San Francisco, and San Francisco Veterans Affairs Medical Center, San Francisco, California, USA
| | - Nina Vardjan
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology—Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Robert Zorec
- Laboratory of Cell Engineering, Celica Biomedical, Ljubljana, Slovenia
- Laboratory of Neuroendocrinology—Molecular Cell Physiology, Institute of Pathophysiology, Faculty of Medicine, University of Ljubljana, Ljubljana, Slovenia
| | - Mary C. McKenna
- Department of Pediatrics and Program in Neuroscience, University of Maryland School of Medicine, Baltimore, Maryland, USA
| |
Collapse
|
7
|
Basu R, Preat T, Plaçais PY. Glial metabolism versatility regulates mushroom body-driven behavioral output in Drosophila. Learn Mem 2024; 31:a053823. [PMID: 38862167 PMCID: PMC11199944 DOI: 10.1101/lm.053823.123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2024] [Accepted: 04/23/2024] [Indexed: 06/13/2024]
Abstract
Providing metabolic support to neurons is now recognized as a major function of glial cells that is conserved from invertebrates to vertebrates. However, research in this field has focused for more than two decades on the relevance of lactate and glial glycolysis for neuronal energy metabolism, while overlooking many other facets of glial metabolism and their impact on neuronal physiology, circuit activity, and behavior. Here, we review recent work that has unveiled new features of glial metabolism, especially in Drosophila, in the modulation of behavioral traits involving the mushroom bodies (MBs). These recent findings reveal that spatially and biochemically distinct modes of glucose-derived neuronal fueling are implemented within the MB in a memory type-specific manner. In addition, cortex glia are endowed with several antioxidant functions, whereas astrocytes can serve as pro-oxidant agents that are beneficial to redox signaling underlying long-term memory. Finally, glial fatty acid oxidation seems to play a dual fail-safe role: first, as a mode of energy production upon glucose shortage, and, second, as a factor underlying the clearance of excessive oxidative load during sleep. Altogether, these integrated studies performed in Drosophila indicate that glial metabolism has a deterministic role on behavior.
Collapse
Affiliation(s)
- Ruchira Basu
- Energy & Memory, Brain Plasticity (UMR 8249), CNRS, ESPCI Paris, PSL Research University, 75005 Paris, France
| | - Thomas Preat
- Energy & Memory, Brain Plasticity (UMR 8249), CNRS, ESPCI Paris, PSL Research University, 75005 Paris, France
| | - Pierre-Yves Plaçais
- Energy & Memory, Brain Plasticity (UMR 8249), CNRS, ESPCI Paris, PSL Research University, 75005 Paris, France
| |
Collapse
|
8
|
Kroll T, Miranda A, Drechsel A, Beer S, Lang M, Drzezga A, Rosa-Neto P, Verhaeghe J, Elmenhorst D, Bauer A. Dynamic neuroreceptor positron emission tomography in non-anesthetized rats using point source based motion correction: A feasibility study with [ 11C]ABP688. J Cereb Blood Flow Metab 2024:271678X241239133. [PMID: 38684219 DOI: 10.1177/0271678x241239133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 05/02/2024]
Abstract
To prevent motion artifacts in small animal positron emission tomography (PET), animals are routinely scanned under anesthesia or physical restraint. Both may potentially alter metabolism and neurochemistry. This study investigates the feasibility of fully awake acquisition and subsequent absolute quantification of dynamic brain PET data via pharmacokinetic modelling in moving rats using the glutamate 5 receptor radioligand [11C]ABP688 and point source based motion correction. Five male rats underwent three dynamic [11C]ABP688 PET scans: two test-retest awake PET scans and one scan under anesthesia for comparison. Specific radioligand binding was determined via the simplified reference tissue model (reference: cerebellum) and outcome parameters BPND and R1 were evaluated in terms of stability and reproducibility. Test-retest measurements in awake animals gave reliable results with high correlations of BPND (y = 1.08 × -0.2, r = 0.99, p < 0.01) and an acceptable variability (mean over all investigated regions 15.7 ± 2.4%). Regional [11C]ABP688 BPNDs under awake and anesthetized conditions were comparable although in awake scans, absolute radioactive peak uptakes were lower and relative blood flow in terms of R1 was higher. Awake small animal PET with absolute quantification of neuroreceptor availability is technically feasible and reproducible thereby providing a suitable alternative whenever effects of anesthesia are undesirable, e.g. in sleep research.
Collapse
Affiliation(s)
- Tina Kroll
- Institute of Neurosciences and Medicine (INM-2), Forschungszentrum Jülich GmbH, Germany
| | - Alan Miranda
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
| | - Alexandra Drechsel
- Institute of Neurosciences and Medicine (INM-2), Forschungszentrum Jülich GmbH, Germany
| | - Simone Beer
- Institute of Neurosciences and Medicine (INM-2), Forschungszentrum Jülich GmbH, Germany
| | - Markus Lang
- Institute of Neurosciences and Medicine (INM-5), Forschungszentrum Jülich GmbH, Germany
| | - Alexander Drzezga
- Institute of Neurosciences and Medicine (INM-2), Forschungszentrum Jülich GmbH, Germany
- Department of Nuclear Medicine, University Hospital Cologne, Germany
- German Center for Neurodegenerative Diseases (DZNE), Bonn-Cologne, Germany
| | - Pedro Rosa-Neto
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, Alzheimer's Disease Research Unit, Douglas Research Institute, Le Centre intégré universitaire de santé et de services sociaux (CIUSSS) de l'Ouest-de-l'Île-de-Montréal; Department of Neurology and Neurosurgery, Psychiatry and Pharmacology and Therapeutics, McGill University, Montreal, Canada
| | - Jeroen Verhaeghe
- Molecular Imaging Center Antwerp, University of Antwerp, Belgium
| | - David Elmenhorst
- Institute of Neurosciences and Medicine (INM-2), Forschungszentrum Jülich GmbH, Germany
- Department of Nuclear Medicine, University Hospital Cologne, Germany
| | - Andreas Bauer
- Institute of Neurosciences and Medicine (INM-2), Forschungszentrum Jülich GmbH, Germany
| |
Collapse
|
9
|
Avilez-Avilez JJ, Medina-Flores MF, Gómez-Gonzalez B. Sleep loss impairs blood-brain barrier function: Cellular and molecular mechanisms. VITAMINS AND HORMONES 2024; 126:77-96. [PMID: 39029977 DOI: 10.1016/bs.vh.2024.02.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/21/2024]
Abstract
Sleep is a physiological process that preserves the integrity of the neuro-immune-endocrine network to maintain homeostasis. Sleep regulates the production and secretion of hormones, neurotransmitters, cytokines and other inflammatory mediators, both at the central nervous system (CNS) and at the periphery. Sleep promotes the removal of potentially toxic metabolites out of the brain through specialized systems such as the glymphatic system, as well as the expression of specific transporters in the blood-brain barrier. The blood-brain barrier maintains CNS homeostasis by selectively transporting metabolic substrates and nutrients into the brain, by regulating the efflux of metabolic waste products, and maintaining bidirectional communication between the periphery and the CNS. All those processes are disrupted during sleep loss. Brain endothelial cells express the blood-brain barrier phenotype, which arises after cell-to-cell interactions with mural cells, like pericytes, and after the release of soluble factors by astroglial endfeet. Astroglia, pericytes and brain endothelial cells respond differently to sleep loss; evidence has shown that sleep loss induces a chronic low-grade inflammatory state at the CNS, which is associated with blood-brain barrier dysfunction. In animal models, blood-brain barrier dysfunction is characterized by increased blood-brain barrier permeability, decreased tight junction protein expression and pericyte detachment from the capillary wall. Blood-brain barrier dysfunction may promote defects in brain clearance of potentially neurotoxic metabolites and byproducts of neural physiology, which may eventually contribute to neurodegenerative diseases. This chapter aims to describe the cellular and molecular mechanisms by which sleep loss modifies the function of the blood-brain barrier.
Collapse
Affiliation(s)
- Jessica Janeth Avilez-Avilez
- Graduate Program in Experimental Biology, Universidad Autónoma Metropolitana, Mexico City, Mexico; Area of Neurosciences, Department of Biology of Reproduction, Universidad Autónoma Metropolitana, Mexico City, Mexico
| | - María Fernanda Medina-Flores
- Graduate Program in Experimental Biology, Universidad Autónoma Metropolitana, Mexico City, Mexico; Area of Neurosciences, Department of Biology of Reproduction, Universidad Autónoma Metropolitana, Mexico City, Mexico
| | - Beatriz Gómez-Gonzalez
- Area of Neurosciences, Department of Biology of Reproduction, Universidad Autónoma Metropolitana, Mexico City, Mexico.
| |
Collapse
|
10
|
Beschorner N, Nedergaard M. Glymphatic system dysfunction in neurodegenerative diseases. Curr Opin Neurol 2024; 37:182-188. [PMID: 38345416 DOI: 10.1097/wco.0000000000001252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/08/2024]
Abstract
PURPOSE OF REVIEW Purpose of this review is to update the ongoing work in the field of glymphatic and neurodegenerative research and to highlight focus areas that are particularly promising. RECENT FINDINGS Multiple reports have over the past decade documented that glymphatic fluid transport is broadly suppressed in neurodegenerative diseases. Most studies have focused on Alzheimer's disease using a variety of preclinical disease models, whereas the clinical work is based on various neuroimaging approaches. It has consistently been reported that brain fluid transport is impaired in patients suffering from Alzheimer's disease compared with age-matched control subjects. SUMMARY An open question in the field is to define the mechanistic underpinning of why glymphatic function is suppressed. Other questions include the opportunities for using glymphatic imaging for diagnostic purposes and in treatment intended to prevent or slow Alzheimer disease progression.
Collapse
Affiliation(s)
- Natalie Beschorner
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen N, Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen N, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical School, Rochester, New York, USA
| |
Collapse
|
11
|
Al‐kuraishy HM, Al‐Gareeb AI, Albuhadily AK, Elewa YHA, AL‐Farga A, Aqlan F, Zahran MH, Batiha GE. Sleep disorders cause Parkinson's disease or the reverse is true: Good GABA good night. CNS Neurosci Ther 2024; 30:e14521. [PMID: 38491789 PMCID: PMC10943276 DOI: 10.1111/cns.14521] [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: 07/13/2023] [Revised: 10/03/2023] [Accepted: 10/23/2023] [Indexed: 03/18/2024] Open
Abstract
BACKGROUND Parkinson's disease (PD) is a progressive neurodegenerative brain disease due to degeneration of dopaminergic neurons (DNs) presented with motor and non-motor symptoms. PD symptoms are developed in response to the disturbance of diverse neurotransmitters including γ-aminobutyric acid (GABA). GABA has a neuroprotective effect against PD neuropathology by protecting DNs in the substantia nigra pars compacta (SNpc). It has been shown that the degeneration of GABAergic neurons is linked with the degeneration of DNs and the progression of motor and non-motor PD symptoms. GABA neurotransmission is a necessary pathway for normal sleep patterns, thus deregulation of GABAergic neurotransmission in PD could be the potential cause of sleep disorders in PD. AIM Sleep disorders affect GABA neurotransmission leading to memory and cognitive dysfunction in PD. For example, insomnia and short sleep duration are associated with a reduction of brain GABA levels. Moreover, PD-related disorders including rigidity and nocturia influence sleep patterns leading to fragmented sleep which may also affect PD neuropathology. However, the mechanistic role of GABA in PD neuropathology regarding motor and non-motor symptoms is not fully elucidated. Therefore, this narrative review aims to clarify the mechanistic role of GABA in PD neuropathology mainly in sleep disorders, and how good GABA improves PD. In addition, this review of published articles tries to elucidate how sleep disorders such as insomnia and REM sleep behavior disorder (RBD) affect PD neuropathology and severity. The present review has many limitations including the paucity of prospective studies and most findings are taken from observational and preclinical studies. GABA involvement in the pathogenesis of PD has been recently discussed by recent studies. Therefore, future prospective studies regarding the use of GABA agonists in the management of PD are suggested to observe their distinct effects on motor and non-motor symptoms. CONCLUSION There is a bidirectional relationship between the pathogenesis of PD and sleep disorders which might be due to GABA deregulation.
Collapse
Affiliation(s)
- Hayder M. Al‐kuraishy
- Department of Clinical Pharmacology and Medicine, College of MedicineAl‐Mustansiriya UniversityBaghdadIraq
| | - Ali I. Al‐Gareeb
- Department of Clinical Pharmacology and Medicine, College of MedicineAl‐Mustansiriya UniversityBaghdadIraq
| | - Ali K. Albuhadily
- Department of Clinical Pharmacology and Medicine, College of MedicineAl‐Mustansiriya UniversityBaghdadIraq
| | - Yaser Hosny Ali Elewa
- Department of Histology and Cytology, Faculty of Veterinary MedicineZagazig UniversityZagazigEgypt
- Faculty of Veterinary MedicineHokkaido UniversitySapporoJapan
| | - Ammar AL‐Farga
- Biochemistry Department, College of SciencesUniversity of JeddahJeddahSaudia Arbia
| | - Faisal Aqlan
- Department of Chemistry, College of SciencesIbb UniversityIbb GovernorateYemen
| | | | - Gaber El‐Saber Batiha
- Department of Pharmacology and Therapeutics, Faculty of Veterinary MedicineDamanhur UniversityDamanhurEgypt
| |
Collapse
|
12
|
Freund W, Weber F. The Function of Sleep and the Treatment of Primary Insomnia. DEUTSCHES ARZTEBLATT INTERNATIONAL 2023; 120:863-870. [PMID: 37942822 PMCID: PMC10840130 DOI: 10.3238/arztebl.m2023.0228] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Revised: 10/16/2023] [Accepted: 10/16/2023] [Indexed: 11/10/2023]
Abstract
BACKGROUND Approximately 21 900 women and 35 300 men developed lung cancer in Germany in 2018, and 16 999 women and 27 882 men died of it. The outcome mainly depends on the tumor stage. In early stages (stage I or II), treatment can be curative; unfortunately, because early-stage lung cancers are generally asymptom - atic, 74% of women and 77% of men already have advanced-stage disease (stage III or IV) at the time of diagnosis. Screening with low-dose computed tomography is an option enabling early diagnosis and curative treatment. METHODS This review is based on pertinent articles retrieved by a selective search of the literature on screening for lung cancer. RESULTS In the studies of lung cancer screening that have been published to date, sensitivity ranged from 68.5% to 93.8%, and specificity from 73.4% to 99.2%. A meta-analysis by the German Federal Office for Radiation Protection revealed a 15% reduction in lung cancer mortality when low-dose computed tomography was used in persons who were judged to be at high risk for lung cancer (risk ratio [RR] 0.85, 95% confidence interval [0.77; 0.95]). 1.9% of subjects died in the screening arm of the meta-analysis, and 2.2% in the control group. The observation periods ranged from 6.6 to 10 years; false-positive rates ranged from 84.9% to 96.4%. Malignant findings were confirmed in 45% to 70% of the biopsies or resective procedures that were performed. CONCLUSION Systematic lung cancer screening with low-dose CT lowers mortality from lung cancer in (current or former) heavy smokers. This benefit must be weighed against the high rate of false-positive findings and overdiagnoses.
Collapse
Affiliation(s)
- Wolfgang Freund
- Neurocenter Biberach
- Diagnostic and Interventional Radiology, Ulm University Hospital, Ulm
| | | |
Collapse
|
13
|
Postnov D, Semyachkina-Glushkovskaya O, Litvinenko E, Kurths J, Penzel T. Mechanisms of Activation of Brain's Drainage during Sleep: The Nightlife of Astrocytes. Cells 2023; 12:2667. [PMID: 37998402 PMCID: PMC10670149 DOI: 10.3390/cells12222667] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2023] [Revised: 11/09/2023] [Accepted: 11/15/2023] [Indexed: 11/25/2023] Open
Abstract
The study of functions, mechanisms of generation, and pathways of movement of cerebral fluids has a long history, but the last decade has been especially productive. The proposed glymphatic hypothesis, which suggests a mechanism of the brain waste removal system (BWRS), caused an active discussion on both the criticism of some of the perspectives and our intensive study of new experimental facts. It was especially found that the intensity of the metabolite clearance changes significantly during the transition between sleep and wakefulness. Interestingly, at the cellular level, a number of aspects of this problem have been focused on, such as astrocytes-glial cells, which, over the past two decades, have been recognized as equal partners of neurons and perform many important functions. In particular, an important role was assigned to astrocytes within the framework of the glymphatic hypothesis. In this review, we return to the "astrocytocentric" view of the BWRS function and the explanation of its activation during sleep from the viewpoint of new findings over the last decade. Our main conclusion is that the BWRS's action may be analyzed both at the systemic (whole-brain) and at the local (cellular) level. The local level means here that the neuro-glial-vascular unit can also be regarded as the smallest functional unit of sleep, and therefore, the smallest functional unit of the BWRS.
Collapse
Affiliation(s)
- Dmitry Postnov
- Department of Optics and Biophotonics, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia;
| | - Oxana Semyachkina-Glushkovskaya
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (O.S.-G.); (J.K.)
- Physics Department, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany
| | - Elena Litvinenko
- Department of Optics and Biophotonics, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia;
| | - Jürgen Kurths
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (O.S.-G.); (J.K.)
- Physics Department, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany
- Potsdam Institute for Climate Impact Research, Telegrafenberg A31, 14473 Potsdam, Germany
| | - Thomas Penzel
- Department of Biology, Saratov State University, Astrakhanskaya Str. 83, 410012 Saratov, Russia; (O.S.-G.); (J.K.)
- Charité — Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| |
Collapse
|
14
|
Wang DJJ, Hua J, Cao D, Ho ML. Neurofluids and the glymphatic system: anatomy, physiology, and imaging. Br J Radiol 2023; 96:20230016. [PMID: 37191063 PMCID: PMC10607419 DOI: 10.1259/bjr.20230016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 04/05/2023] [Accepted: 04/14/2023] [Indexed: 05/17/2023] Open
Abstract
First described in 2012, the glymphatic system is responsible for maintaining homeostasis within the central nervous system, including nutrient delivery, waste clearance, and consistency of the ionic microenvironment. It is comprised of glial cells and barrier systems that modulate neurofluid production, circulation, and exchange. Experimental interrogation of neurofluid dynamics is restricted to ex vivo and in vitro studies in animals and humans, therefore diagnostic imaging plays an important role in minimally invasive evaluation. This review article will synthesize current knowledge and theories regarding neurofluid circulation and implications for neuroimaging. First, we will discuss the anatomy of the neurogliovascular unit, including paravascular and perivascular pathways of fluid exchange. In addition, we will summarize the structure and function of barrier systems including the blood-brain, blood-cerebrospinal fluid, and brain-cerebrospinal fluid barriers. Next, we will mention physiologic factors that yield normal variations in neurofluid circulation, and how various disease pathologies can disrupt glymphatic drainage pathways. Lastly, we will cover the spectrum of diagnostic imaging and interventional techniques with relevance to glymphatic structure, flow, and function. We conclude by highlighting current barriers and future directions for translational imaging and applications to neurologic disorders.
Collapse
Affiliation(s)
- Danny JJ Wang
- Mark & Mary Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, United States
| | | | | | - Mai-Lan Ho
- Nationwide Children’s Hospital and The Ohio State University, Columbus, Ohio, United States
| |
Collapse
|
15
|
Kim E, Van Reet J, Yoo SS. Cerebrospinal fluid solute transport associated with sensorimotor brain activity in rodents. Sci Rep 2023; 13:17002. [PMID: 37813871 PMCID: PMC10562378 DOI: 10.1038/s41598-023-43920-2] [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: 05/24/2023] [Accepted: 09/29/2023] [Indexed: 10/11/2023] Open
Abstract
Cerebrospinal fluid (CSF) is crucial for maintaining neuronal homeostasis, providing nutrition, and removing metabolic waste from the brain. However, the relationship between neuronal activity and CSF solute transport remains poorly understood. To investigate the effect of regional neuronal activity on CSF solute transport, Sprague-Dawley rats (all male, n = 30) under anesthesia received an intracisternal injection of a fluorescent tracer (Texas Red ovalbumin) and were subjected to unilateral electrical stimulation of a forelimb. Two groups (n = 10 each) underwent two different types of stimulation protocols for 90 min, one including intermittent 7.5-s resting periods and the other without rest. The control group was not stimulated. Compared to the control, the stimulation without resting periods led to increased transport across most of the cortical areas, including the ventricles. The group that received intermittent stimulation showed an elevated level of solute uptake in limited areas, i.e., near/within the ventricles and on the ventral brain surface. Interhemispheric differences in CSF solute transport were also found in the cortical regions that overlap with the forelimb sensorimotor area. These findings suggest that neuronal activity may trigger local and brain-wide increases in CSF solute transport, contributing to waste clearance.
Collapse
Affiliation(s)
- Evgenii Kim
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Jared Van Reet
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA
| | - Seung-Schik Yoo
- Department of Radiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis Street, Boston, MA, 02115, USA.
| |
Collapse
|
16
|
Sarker A, Suh M, Choi Y, Park JY, Lee YS, Lee DS. Intrathecal [ 64Cu]Cu-albumin PET reveals age-related decline of lymphatic drainage of cerebrospinal fluid. Sci Rep 2023; 13:12930. [PMID: 37558700 PMCID: PMC10412645 DOI: 10.1038/s41598-023-39903-y] [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: 03/18/2023] [Accepted: 08/01/2023] [Indexed: 08/11/2023] Open
Abstract
Age-related cognitive decline is associated with dysfunctional lymphatic drainage of cerebrospinal fluid (CSF) through meningeal lymphatic vessels. In this study, intrathecal [64Cu]Cu-albumin positron emission tomography (PET) was applied in mice to evaluate lymphatic drainage of CSF and its variation with age. [64Cu]Cu-albumin PET was performed at multiple time points after intrathecal injection of [64Cu]Cu-albumin at an infusion rate of 700 nl/min in adult and aged mice (15-25 months old). CSF clearance and paravertebral lymph nodes were quantified after injection and during the stationary phase. Stationary phase of the next day followed the initial perturbed state by injection of 6 ul (1/7 of total CSF volume) and CSF clearance half-time from the subarachnoid space was 93.4 ± 19.7 and 123.3 ± 15.6 min in adult and aged mice (p = 0.01), respectively. While the % injected dose of CSF space were higher, the activity of the paravertebral lymph nodes were lower in the aged mice on the next day. [64Cu]Cu-albumin PET enabled us to quantify CSF-lymphatic drainage across all levels of brain spinal cords and to visualize and quantify lymph node activity due to CSF drainage. [64Cu]Cu-albumin PET revealed the age-related decrease of the lymphatic drainage of CSF due to this decreased drainage from the subarachnoid space, especially during the stationary phase, in aged mice.
Collapse
Affiliation(s)
- Azmal Sarker
- Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Korea
| | - Minseok Suh
- Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Korea.
- Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea.
- Biomedical Research Center, Seoul National University Hospital, Seoul, Korea.
| | - Yoori Choi
- Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea
- Biomedical Research Center, Seoul National University Hospital, Seoul, Korea
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea
| | - Ji Yong Park
- Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Korea
- Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea
| | - Yun-Sang Lee
- Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Korea
- Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea
| | - Dong Soo Lee
- Department of Nuclear Medicine, College of Medicine, Seoul National University, Seoul, Korea.
- Department of Nuclear Medicine, Seoul National University Hospital, Seoul, Korea.
- Department of Molecular Medicine and Biopharmaceutical Sciences, Graduate School of Convergence Science and Technology, Seoul National University, Seoul, Korea.
- Medical Research Center, College of Medicine, Seoul National University, Seoul, Korea.
- Medical Science and Engineering, School of Convergence Science and Technology, Pohang University of Science and Technology (POSTECH), Pohang, Korea.
| |
Collapse
|
17
|
Gao Y, Liu K, Zhu J. Glymphatic system: an emerging therapeutic approach for neurological disorders. Front Mol Neurosci 2023; 16:1138769. [PMID: 37485040 PMCID: PMC10359151 DOI: 10.3389/fnmol.2023.1138769] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 06/21/2023] [Indexed: 07/25/2023] Open
Abstract
The functions of the glymphatic system include clearance of the metabolic waste and modulation of the water transport in the brain, and it forms a brain-wide fluid network along with cerebrospinal fluid (CSF) and interstitial fluid (ISF). The glymphatic pathway consists of periarterial influx of CSF, astrocyte-mediated interchange between ISF and CSF supported by aquaporin-4 (AQP4) on the endfeet of astrocyte around the periarterioles, and perivenous efflux of CSF. Finally, CSF is absorbed by the arachnoid granules or flows into the cervical lymphatic vessels. There is growing evidence from animal experiments that the glymphatic system dysfunction is involved in many neurological disorders, such as Alzheimer's disease, stroke, epilepsy, traumatic brain injury and meningitis. In this review, we summarize the latest progress on the glymphatic system and its driving factors, as well as changes in the glymphatic pathway in different neurological diseases. We significantly highlight the likely therapeutic approaches for glymphatic pathway in neurological diseases, and the importance of AQP4 and normal sleep architecture in this process.
Collapse
Affiliation(s)
- Ying Gao
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Changchun, China
| | - Kangding Liu
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Changchun, China
| | - Jie Zhu
- Department of Neurology, Neuroscience Centre, The First Hospital of Jilin University, Changchun, China
- Department of Neurobiology, Care Sciences and Society, Karolinska Institute, Karolinska University Hospital, Solna, Sweden
| |
Collapse
|
18
|
Peters ME, Lyketsos CG. The glymphatic system's role in traumatic brain injury-related neurodegeneration. Mol Psychiatry 2023; 28:2707-2715. [PMID: 37185960 DOI: 10.1038/s41380-023-02070-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/25/2022] [Revised: 04/03/2023] [Accepted: 04/05/2023] [Indexed: 05/17/2023]
Abstract
In at least some individuals who suffer a traumatic brain injury (TBI), there exists a risk of future neurodegenerative illness. This review focuses on the association between the brain-based paravascular drainage pathway known as the "glymphatic system" and TBI-related neurodegeneration. The glymphatic system is composed of cerebrospinal fluid (CSF) flowing into the brain parenchyma along paravascular spaces surrounding penetrating arterioles where it mixes with interstitial fluid (ISF) before being cleared along paravenous drainage pathways. Aquaporin-4 (AQP4) water channels on astrocytic end-feet appear essential for the functioning of this system. The current literature linking glymphatic system disruption and TBI-related neurodegeneration is largely based on murine models with existing human research focused on the need for biomarkers of glymphatic system function (e.g., neuroimaging modalities). Key findings from the existing literature include evidence of glymphatic system flow disruption following TBI, mechanisms of this decreased flow (i.e., AQP4 depolarization), and evidence of protein accumulation and deposition (e.g., amyloid β, tau). The same studies suggest that glymphatic dysfunction leads to subsequent neurodegeneration, cognitive decline, and/or behavioral change although replication in humans is needed. Identified emerging topics from the literature are as follows: link between TBI, sleep, and glymphatic system dysfunction; influence of glymphatic system disruption on TBI biomarkers; and development of novel treatments for glymphatic system disruption following TBI. Although a burgeoning field, more research is needed to elucidate the role of glymphatic system disruption in TBI-related neurodegeneration.
Collapse
Affiliation(s)
- Matthew E Peters
- Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Constantine G Lyketsos
- Department of Psychiatry and Behavioral Sciences, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| |
Collapse
|
19
|
Sigurdsson B, Hauglund NL, Lilius TO, Mogensen FLH, Mortensen KN, Beschorner N, Klinger L, Bærentzen SL, Rosenholm MP, Shalgunov V, Herth M, Mori Y, Nedergaard M. A SPECT-based method for dynamic imaging of the glymphatic system in rats. J Cereb Blood Flow Metab 2023; 43:1153-1165. [PMID: 36809165 PMCID: PMC10291457 DOI: 10.1177/0271678x231156982] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/17/2022] [Accepted: 12/07/2022] [Indexed: 02/23/2023]
Abstract
The glymphatic system is a brain-wide waste drainage system that promotes cerebrospinal fluid circulation through the brain to remove waste metabolites. Currently, the most common methods for assessing glymphatic function are ex vivo fluorescence microscopy of brain slices, macroscopic cortical imaging, and MRI. While all these methods have been crucial for expanding our understanding of the glymphatic system, new techniques are required to overcome their specific drawbacks. Here, we evaluate SPECT/CT imaging as a tool to assess glymphatic function in different anesthesia-induced brain states using two radiolabeled tracers, [111In]-DTPA and [99mTc]-NanoScan. Using SPECT, we confirmed the existence of brain state-dependent differences in glymphatic flow and we show brain state-dependent differences of CSF flow kinetics and CSF egress to the lymph nodes. We compare SPECT and MRI for imaging glymphatic flow and find that the two imaging modalities show the same overall pattern of CSF flow, but that SPECT was specific across a greater range of tracer concentrations than MRI. Overall, we find that SPECT imaging is a promising tool for imaging the glymphatic system, and that qualities such as high sensitivity and the variety of available tracers make SPECT imaging a good alternative for glymphatic research.
Collapse
Affiliation(s)
- Björn Sigurdsson
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Natalie L Hauglund
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Tuomas O Lilius
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- INDIVIDRUG Research Program, University of Helsinki, Finland
- Department of Pharmacology, University of Helsinki, Finland
- Department of Emergency Medicine and Services, Helsinki University Hospital and University of Helsinki, Finland
| | - Frida L-H Mogensen
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- Neuro-Immunology Group, Department of Cancer Research, Luxembourg Institute of Health, Luxembourg, Luxembourg
- Doctoral School of Science and Technology, University of Luxembourg, Esch-sur-Alzette, Luxembourg
| | | | - Natalie Beschorner
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Laura Klinger
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Simone L Bærentzen
- Translational Neuropsychiatry Unit, Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
- Department of Nuclear Medicine and PET Center, Aarhus University Hospital, Aarhus, Denmark
| | - Marko P Rosenholm
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Vladimir Shalgunov
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
| | - Matthias Herth
- Department of Drug Design and Pharmacology, University of Copenhagen, Denmark
- Department of Clinical Physiology, Copenhagen University Hospital, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, USA
| |
Collapse
|
20
|
Semyachkina-Glushkovskaya O, Penzel T, Poluektov M, Fedosov I, Tzoy M, Terskov A, Blokhina I, Sidorov V, Kurths J. Phototherapy of Alzheimer's Disease: Photostimulation of Brain Lymphatics during Sleep: A Systematic Review. Int J Mol Sci 2023; 24:10946. [PMID: 37446135 DOI: 10.3390/ijms241310946] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 06/18/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
The global number of people with Alzheimer's disease (AD) doubles every 5 years. It has been established that unless an effective treatment for AD is found, the incidence of AD will triple by 2060. However, pharmacological therapies for AD have failed to show effectiveness and safety. Therefore, the search for alternative methods for treating AD is an urgent problem in medicine. The lymphatic drainage and removal system of the brain (LDRSB) plays an important role in resistance to the progression of AD. The development of methods for augmentation of the LDRSB functions may contribute to progress in AD therapy. Photobiomodulation (PBM) is considered to be a non-pharmacological and safe approach for AD therapy. Here, we highlight the most recent and relevant studies of PBM for AD. We focus on emerging evidence that indicates the potential benefits of PBM during sleep for modulation of natural activation of the LDRSB at nighttime, providing effective removal of metabolites, including amyloid-β, from the brain, leading to reduced progression of AD. Our review creates a new niche in the therapy of brain diseases during sleep and sheds light on the development of smart sleep technologies for neurodegenerative diseases.
Collapse
Affiliation(s)
- Oxana Semyachkina-Glushkovskaya
- Department of Physics, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Thomas Penzel
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
- Interdisziplinäres Schlafmedizinisches Zentrum, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany
| | - Mikhail Poluektov
- Department of Nervous Diseases, Sechenov First Moscow State Medical University, Bolshaya Pirogovskaya 2, Building 4, 119435 Moscow, Russia
| | - Ivan Fedosov
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Maria Tzoy
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Andrey Terskov
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Inna Blokhina
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
| | - Viktor Sidorov
- Company "Lazma" for Research and Production Enterprise of Laser Medical Equipment, Kuusinena Str. 11, 123308 Moscow, Russia
| | - Jürgen Kurths
- Department of Physics, Humboldt University, Newtonstrasse 15, 12489 Berlin, Germany
- Department of Biology, Saratov State University, Astrakhanskaya 82, 410012 Saratov, Russia
- Department of Complexity Science, Potsdam Institute for Climate Impact Research, Telegrafenberg A31, 14473 Potsdam, Germany
| |
Collapse
|
21
|
Ding Z, Fan X, Zhang Y, Yao M, Wang G, Dong Y, Liu J, Song W. The glymphatic system: a new perspective on brain diseases. Front Aging Neurosci 2023; 15:1179988. [PMID: 37396658 PMCID: PMC10308198 DOI: 10.3389/fnagi.2023.1179988] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2023] [Accepted: 05/29/2023] [Indexed: 07/04/2023] Open
Abstract
The glymphatic system is a brain-wide perivascular pathway driven by aquaporin-4 on the endfeet of astrocytes, which can deliver nutrients and active substances to the brain parenchyma through periarterial cerebrospinal fluid (CSF) influx pathway and remove metabolic wastes through perivenous clearance routes. This paper summarizes the composition, overall fluid flow, solute transport, related diseases, affecting factors, and preclinical research methods of the glymphatic system. In doing so, we aim to provide direction and reference for more relevant researchers in the future.
Collapse
|
22
|
Simoes Braga Boisserand L, Bouchart J, Geraldo LH, Lee S, Sanganahalli BG, Parent M, Zhang S, Xue Y, Skarica M, Guegan J, Li M, Liu X, Poulet M, Askanase M, Osherov A, Spajer M, Kamouh MRE, Eichmann A, Alitalo K, Zhou J, Sestan N, Sansing LH, Benveniste H, Hyder F, Thomas JL. VEGF-C promotes brain-derived fluid drainage, confers neuroprotection, and improves stroke outcomes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.30.542708. [PMID: 37398128 PMCID: PMC10312491 DOI: 10.1101/2023.05.30.542708] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/04/2023]
Abstract
Meningeal lymphatic vessels promote tissue clearance and immune surveillance in the central nervous system (CNS). Vascular endothelium growth factor-C (VEGF-C) is essential for meningeal lymphatic development and maintenance and has therapeutic potential for treating neurological disorders, including ischemic stroke. We have investigated the effects of VEGF-C overexpression on brain fluid drainage, single cell transcriptome in the brain, and stroke outcomes in adult mice. Intra-cerebrospinal fluid administration of an adeno-associated virus expressing VEGF-C (AAV-VEGF-C) increases the CNS lymphatic network. Post-contrast T1 mapping of the head and neck showed that deep cervical lymph node size and drainage of CNS-derived fluids were increased. Single nuclei RNA sequencing revealed a neuro-supportive role of VEGF-C via upregulation of calcium and brain-derived neurotrophic factor (BDNF) signaling pathways in brain cells. In a mouse model of ischemic stroke, AAV-VEGF-C pretreatment reduced stroke injury and ameliorated motor performances in the subacute stage. AAV-VEGF-C thus promotes CNS-derived fluid and solute drainage, confers neuroprotection, and reduces ischemic stroke damage. Short abstract Intrathecal delivery of VEGF-C increases the lymphatic drainage of brain-derived fluids confers neuroprotection, and improves neurological outcomes after ischemic stroke.
Collapse
|
23
|
Ye D, Chen S, Liu Y, Weixel C, Hu Z, Yuan J, Chen H. Mechanically manipulating glymphatic transport by ultrasound combined with microbubbles. Proc Natl Acad Sci U S A 2023; 120:e2212933120. [PMID: 37186852 PMCID: PMC10214201 DOI: 10.1073/pnas.2212933120] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 04/11/2023] [Indexed: 05/17/2023] Open
Abstract
The glymphatic system is a perivascular fluid transport system for waste clearance. Glymphatic transport is believed to be driven by the perivascular pumping effect created by the pulsation of the arterial wall caused by the cardiac cycle. Ultrasound sonication of circulating microbubbles (MBs) in the cerebral vasculature induces volumetric expansion and contraction of MBs that push and pull on the vessel wall to generate a MB pumping effect. The objective of this study was to evaluate whether glymphatic transport can be mechanically manipulated by focused ultrasound (FUS) sonication of MBs. The glymphatic pathway in intact mouse brains was studied using intranasal administration of fluorescently labeled albumin as fluid tracers, followed by FUS sonication at a deep brain target (thalamus) in the presence of intravenously injected MBs. Intracisternal magna injection, the conventional technique used in studying glymphatic transport, was employed to provide a comparative reference. Three-dimensional confocal microscopy imaging of optically cleared brain tissue revealed that FUS sonication enhanced the transport of fluorescently labeled albumin tracer in the perivascular space (PVS) along microvessels, primarily the arterioles. We also obtained evidence of FUS-enhanced penetration of the albumin tracer from the PVS into the interstitial space. This study revealed that ultrasound combined with circulating MBs could mechanically enhance glymphatic transport in the brain.
Collapse
Affiliation(s)
- Dezhuang Ye
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO63130
| | - Si Chen
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO63130
| | - Yajie Liu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO63130
| | - Charlotte Weixel
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO63130
| | - Zhongtao Hu
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO63130
| | - Jinyun Yuan
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO63130
| | - Hong Chen
- Department of Biomedical Engineering, Washington University in St. Louis, St. Louis, MO63130
- Department of Radiation Oncology, Washington University School of Medicine, St. Louis, MO63130
- Department of Neurosurgery, Washington University School of Medicine, St. Louis, MO63110
- Department of Neurosurgery, Division of Neurotechnology, Washington University School of Medicine, St. Louis, MO 63110
| |
Collapse
|
24
|
Chu Y, Hirst WD, Kordower JH. Mixed pathology as a rule, not exception: Time to reconsider disease nosology. HANDBOOK OF CLINICAL NEUROLOGY 2023; 192:57-71. [PMID: 36796948 DOI: 10.1016/b978-0-323-85538-9.00012-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Parkinson's disease is a progressive neurodegenerative disorder that is associated with motor and nonmotor symptoms. Accumulation of misfolded α-synuclein is considered a key pathological feature during disease initiation and progression. While clearly deemed a synucleinopathy, the development of amyloid-β plaques, tau-containing neurofibrillary tangles, and even TDP-43 protein inclusions occur within the nigrostriatal system and in other brain regions. In addition, inflammatory responses, manifested by glial reactivity, T-cell infiltration, and increased expression of inflammatory cytokines, plus other toxic mediators derived from activated glial cells, are currently recognized as prominent drivers of Parkinson's disease pathology. However, copathologies have increasingly been recognized as the rule (>90%) and not the exception, with Parkinson's disease cases on average exhibiting three different copathologies. While microinfarcts, atherosclerosis, arteriolosclerosis, and cerebral amyloid angiopathy may have an impact on disease progression, α-synuclein, amyloid-β, and TDP-43 pathology do not seem to contribute to progression.
Collapse
Affiliation(s)
- Yaping Chu
- ASU-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ, United States
| | - Warren D Hirst
- Neurodegenerative Diseases Research Unit, Biogen, Boston, MA, United States
| | - Jeffrey H Kordower
- ASU-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ, United States.
| |
Collapse
|
25
|
The Associations between Polysomnographic Parameters and Memory Impairment among Patients with Obstructive Sleep Apnea: A 10-Year Hospital-Based Longitudinal Study. Biomedicines 2023; 11:biomedicines11020621. [PMID: 36831157 PMCID: PMC9953626 DOI: 10.3390/biomedicines11020621] [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: 01/18/2023] [Revised: 02/05/2023] [Accepted: 02/14/2023] [Indexed: 02/22/2023] Open
Abstract
Obstructive sleep apnea (OSA) has been associated with cognitive decline via several mechanisms, including intermittent hypoxemia, sleep fragmentation, and neuroinflammation. The neurological consequences of OSA have evolved into a major biopsychosocial concern in the elderly, especially memory impairment. We aimed to identify the polysomnographic (PSG) parameters capable of predicting memory impairment among OSA patients at or over age 50 with OSA. We reviewed the 10-year electronic medical records of OSA patients and compared the initial PSG parameters between those presenting and not presenting self-reported memory impairment. We conducted subgroup analyses based on OSA severity and performed multivariate analysis to correlate PSG parameters with memory impairment. The result showed that 25 out of the 156 (16%) investigated patients experienced self-reported memory impairment during follow-up. As compared to OSA patients without self-reported memory impairment, those reported with self-reported memory impairment had a higher oxygen desaturation index (ODI) (23.9 ± 17.8 versus 18.2 ± 12.0, p = 0.048). Regarding the associations between apnea-hypopnea index (AHI) as well as ODI and self-reported memory impairment among OSA subgroups classified by severity, the associations were only evident in the severe OSA subgroup in both univariate (p < 0.001; p = 0.005) and multivariate analyses (p = 0.014; p = 0.018). We concluded that AHI and ODI are the most relevant PSG parameters in predicting memory impairment in severe OSA patients.
Collapse
|
26
|
Brain Waste Removal System and Sleep: Photobiomodulation as an Innovative Strategy for Night Therapy of Brain Diseases. Int J Mol Sci 2023; 24:ijms24043221. [PMID: 36834631 PMCID: PMC9965491 DOI: 10.3390/ijms24043221] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/28/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023] Open
Abstract
Emerging evidence suggests that an important function of the sleeping brain is the removal of wastes and toxins from the central nervous system (CNS) due to the activation of the brain waste removal system (BWRS). The meningeal lymphatic vessels (MLVs) are an important part of the BWRS. A decrease in MLV function is associated with Alzheimer's and Parkinson's diseases, intracranial hemorrhages, brain tumors and trauma. Since the BWRS is activated during sleep, a new idea is now being actively discussed in the scientific community: night stimulation of the BWRS might be an innovative and promising strategy for neurorehabilitation medicine. This review highlights new trends in photobiomodulation of the BWRS/MLVs during deep sleep as a breakthrough technology for the effective removal of wastes and unnecessary compounds from the brain in order to increase the neuroprotection of the CNS as well as to prevent or delay various brain diseases.
Collapse
|
27
|
van der Thiel MM, Backes WH, Ramakers IHGB, Jansen JFA. Novel developments in non-contrast enhanced MRI of the perivascular clearance system: What are the possibilities for Alzheimer's disease research? Neurosci Biobehav Rev 2023; 144:104999. [PMID: 36529311 DOI: 10.1016/j.neubiorev.2022.104999] [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: 06/21/2022] [Revised: 11/21/2022] [Accepted: 12/10/2022] [Indexed: 12/23/2022]
Abstract
The cerebral waste clearance system (i.e, glymphatic or intramural periarterial drainage) works through a network of perivascular spaces (PVS). Dysfunction of this system likely contributes to aggregation of Amyloid-β and subsequent toxic plaques in Alzheimer's disease (AD). A promising, non-invasive technique to study this system is MRI, though applications in dementia are still scarce. This review focusses on recent non-contrast enhanced (non-CE) MRI techniques which determine and visualise physiological aspects of the clearance system at multiple levels, i.e., cerebrospinal fluid flow, PVS-flow and interstitial fluid movement. Furthermore, various MRI studies focussing on aspects of the clearance system which are relevant to AD are discussed, such as studies on ageing, sleep alterations, and cognitive decline. Additionally, the complementary function of non-CE to CE methods is elaborated upon. We conclude that non-CE studies have great potential to determine which parts of the waste clearance system are affected by AD and in which stages of cognitive impairment dysfunction of this system occurs, which could allow future clinical trials to target these specific mechanisms.
Collapse
Affiliation(s)
- Merel M van der Thiel
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands; Department of Psychiatry &Neuropsychology, Maastricht University, Maastricht, the Netherlands; School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Walter H Backes
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands; School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands; School for Cardiovascular Disease, Maastricht University, Maastricht, the Netherlands
| | - Inez H G B Ramakers
- Department of Psychiatry &Neuropsychology, Maastricht University, Maastricht, the Netherlands; School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Jacobus F A Jansen
- Department of Radiology & Nuclear Medicine, Maastricht University Medical Center, Maastricht, the Netherlands; School for Mental Health & Neuroscience, Maastricht University, Maastricht, the Netherlands; Department of Electrical Engineering, Eindhoven University of Technology, Eindhoven, the Netherlands.
| |
Collapse
|
28
|
Guo R, Vaughan DT, Rojo ALA, Huang YH. Sleep-mediated regulation of reward circuits: implications in substance use disorders. Neuropsychopharmacology 2023; 48:61-78. [PMID: 35710601 PMCID: PMC9700806 DOI: 10.1038/s41386-022-01356-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/07/2022] [Revised: 05/22/2022] [Accepted: 05/27/2022] [Indexed: 12/11/2022]
Abstract
Our modern society suffers from both pervasive sleep loss and substance abuse-what may be the indications for sleep on substance use disorders (SUDs), and could sleep contribute to the individual variations in SUDs? Decades of research in sleep as well as in motivated behaviors have laid the foundation for us to begin to answer these questions. This review is intended to critically summarize the circuit, cellular, and molecular mechanisms by which sleep influences reward function, and to reveal critical challenges for future studies. The review also suggests that improving sleep quality may serve as complementary therapeutics for treating SUDs, and that formulating sleep metrics may be useful for predicting individual susceptibility to SUDs and other reward-associated psychiatric diseases.
Collapse
Affiliation(s)
- Rong Guo
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA
- Allen Institute, Seattle, WA, 98109, USA
| | - Dylan Thomas Vaughan
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA
- The Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA, USA
| | - Ana Lourdes Almeida Rojo
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA
- The Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA, USA
| | - Yanhua H Huang
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA, 15219, USA.
- The Center for Neuroscience at the University of Pittsburgh, Pittsburgh, PA, USA.
| |
Collapse
|
29
|
Cavaillès C, Berr C, Helmer C, Gabelle A, Jaussent I, Dauvilliers Y. Complaints of daytime sleepiness, insomnia, hypnotic use, and risk of dementia: a prospective cohort study in the elderly. Alzheimers Res Ther 2022; 14:12. [PMID: 35057850 PMCID: PMC8780361 DOI: 10.1186/s13195-021-00952-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 12/20/2021] [Indexed: 01/13/2023]
Abstract
Abstract
Background
Sleep disturbances are common in elderly and occur frequently in dementia. The impact of excessive daytime sleepiness (EDS), insomnia complaints, sleep quality, and hypnotics on the risk of all-cause dementia, Alzheimer disease (AD), and dementia with vascular component (DVC) remains unclear, as does the association between sleep profile and plasma β-amyloid levels.
Methods
Analyses were carried out on 6851 participants aged 65 years and over randomly recruited from three French cities and free of dementia at baseline. A structured interview and self-questionnaire assessed sleep complaints (EDS, insomnia complaints, sleep quality) and medications at baseline. Incident cases of dementia were diagnosed systematically over a 12-year period. Multivariate Cox models were used to estimate the risk of dementia associated with the sleep complaints considered individually and globally. Plasma β-amyloid levels were measured by an xMAP-based assay technology in 984 subjects.
Results
After adjustment for socio-demographic characteristics, lifestyle, APOE-ε4, cardiovascular factors, and depressive status, EDS had a higher risk of all-cause dementia (HR = 1.21; 95%CI = [1.01–1.46]) and DVC (HR = 1.58; 95%CI = [1.07–2.32]) but not AD. Persistent use of hypnotics increased the risk for all-cause dementia, specifically AD (HR = 1.28; 95%CI = [1.04–1.58]), but not DVC. No association was found for insomnia complaints and sleep quality taken as individual factors or combined with EDS on the risk of dementia. No association was found between β-amyloid, sleep complaints, and incident dementia.
Conclusions
The results suggest a deleterious role of EDS and hypnotics on dementia. Further studies are required to elucidate the mechanisms involved in these associations and whether its management can prevent the risk of dementia.
Collapse
|
30
|
Role of the glymphatic system in idiopathic intracranial hypertension. Clin Neurol Neurosurg 2022; 222:107446. [DOI: 10.1016/j.clineuro.2022.107446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Revised: 09/13/2022] [Accepted: 09/14/2022] [Indexed: 11/23/2022]
|
31
|
Jin R, Chan AKY, Wu J, Lee TMC. Relationships between Inflammation and Age-Related Neurocognitive Changes. Int J Mol Sci 2022; 23:12573. [PMID: 36293430 PMCID: PMC9604276 DOI: 10.3390/ijms232012573] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Revised: 07/28/2022] [Accepted: 07/29/2022] [Indexed: 11/18/2022] Open
Abstract
The relationship between inflammation and age-related neurocognitive changes is significant, which may relate to the age-related immune dysfunctions characterized by the senescence of immune cells and elevated inflammatory markers in the peripheral circulation and the central nervous system. In this review, we discuss the potential mechanisms, including the development of vascular inflammation, neuroinflammation, organelle dysfunctions, abnormal cholesterol metabolism, and glymphatic dysfunctions as well as the role that the key molecules play in the immune-cognition interplay. We propose potential therapeutic pharmacological and behavioral strategies for ameliorating age-related neurocognitive changes associated with inflammation. Further research to decipher the multidimensional roles of chronic inflammation in normal and pathological aging processes will help unfold the pathophysiological mechanisms underpinning neurocognitive disorders. The insight gained will lay the path for developing cost-effective preventative measures and the buffering or delaying of age-related neurocognitive decline.
Collapse
Affiliation(s)
- Run Jin
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong 999077, China
- Laboratory of Neuropsychology and Human Neuroscience, The University of Hong Kong, Hong Kong 999077, China
| | - Aidan Kai Yeung Chan
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong 999077, China
- Faculty of Medicine, The University of Hong Kong, Hong Kong 999077, China
| | - Jingsong Wu
- College of Rehabilitation Medicine, Fujian University of Traditional Chinese Medicine, Fuzhou 350108, China
| | - Tatia Mei Chun Lee
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong 999077, China
- Laboratory of Neuropsychology and Human Neuroscience, The University of Hong Kong, Hong Kong 999077, China
| |
Collapse
|
32
|
Bohr T, Hjorth PG, Holst SC, Hrabětová S, Kiviniemi V, Lilius T, Lundgaard I, Mardal KA, Martens EA, Mori Y, Nägerl UV, Nicholson C, Tannenbaum A, Thomas JH, Tithof J, Benveniste H, Iliff JJ, Kelley DH, Nedergaard M. The glymphatic system: Current understanding and modeling. iScience 2022; 25:104987. [PMID: 36093063 PMCID: PMC9460186 DOI: 10.1016/j.isci.2022.104987] [Citation(s) in RCA: 88] [Impact Index Per Article: 44.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
We review theoretical and numerical models of the glymphatic system, which circulates cerebrospinal fluid and interstitial fluid around the brain, facilitating solute transport. Models enable hypothesis development and predictions of transport, with clinical applications including drug delivery, stroke, cardiac arrest, and neurodegenerative disorders like Alzheimer's disease. We sort existing models into broad categories by anatomical function: Perivascular flow, transport in brain parenchyma, interfaces to perivascular spaces, efflux routes, and links to neuronal activity. Needs and opportunities for future work are highlighted wherever possible; new models, expanded models, and novel experiments to inform models could all have tremendous value for advancing the field.
Collapse
Affiliation(s)
- Tomas Bohr
- Department of Physics, Technical University of Denmark, 2800 Kgs. Lyngby, Denmark
| | - Poul G. Hjorth
- Department of Applied Mathematics and Computer Science, Technical University of Denmark, Richard Petersens Plads, 2800 Kgs. Lyngby, Denmark
| | - Sebastian C. Holst
- Neuroscience and Rare Diseases Discovery and Translational Area, Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, Grenzacherstrasse 124, 4070 Basel, Switzerland
| | - Sabina Hrabětová
- Department of Cell Biology and The Robert Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, NY, USA
| | - Vesa Kiviniemi
- Oulu Functional NeuroImaging, Department of Diagnostic Radiology, MRC, Oulu University Hospital, Oulu, Finland
- Medical Imaging, Physics and Technology, the Faculty of Medicine, University of Oulu, Oulu, Finland
| | - Tuomas Lilius
- Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Department of Emergency Medicine and Services, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
| | - Iben Lundgaard
- Department of Experimental Medical Science, Lund University, Lund, Sweden
- Wallenberg Centre for Molecular Medicine, Lund University, Lund, Sweden
| | - Kent-Andre Mardal
- Department of Mathematics, University of Oslo, Oslo, Norway
- Simula Research Laboratory, Department of Numerical Analysis and Scientific Computing, Oslo, Norway
| | | | - Yuki Mori
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - U. Valentin Nägerl
- Instítut Interdisciplinaire de Neurosciences, Université de Bordeaux / CNRS UMR 5297, Centre Broca Nouvelle-Aquitaine, 146 rue Léo Saignat, CS 61292 Case 130, 33076 Bordeaux Cedex France
| | - Charles Nicholson
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, USA
- Department of Cell Biology, SUNY Downstate Health Sciences University, Brooklyn, NY, USA
| | - Allen Tannenbaum
- Departments of Computer Science/ Applied Mathematics and Statistics, Stony Brook University, Stony Brook, NY, USA
| | - John H. Thomas
- Department of Mechanical Engineering, University of Rochester, Rochester, 14627 NY, USA
| | - Jeffrey Tithof
- Department of Mechanical Engineering, University of Minnesota, Minneapolis, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
- Department of Biomedical Engineering, Yale School of Medicine, New Haven, CT, USA
| | - Jeffrey J. Iliff
- VISN 20 Mental Illness Research, Education and Clinical Center, VA Puget Sound Health Care System, Seattle, WA, USA
- Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
- Department of Neurology, University of Washington School of Medicine, Seattle, WA, USA
| | - Douglas H. Kelley
- Department of Mechanical Engineering, University of Rochester, Rochester, 14627 NY, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, 14642 NY, USA
| |
Collapse
|
33
|
The Water Transport System in Astrocytes–Aquaporins. Cells 2022; 11:cells11162564. [PMID: 36010640 PMCID: PMC9406552 DOI: 10.3390/cells11162564] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/26/2022] [Accepted: 08/08/2022] [Indexed: 11/16/2022] Open
Abstract
Highlights (AQPs) are transmembrane proteins responsible for fast water movement across cell membranes, including those of astrocytes. The expression and subcellular localization of AQPs in astrocytes are highly dynamic under physiological and pathological conditions. Besides their primary function in water homeostasis, AQPs participate in many ancillary functions including glutamate clearance in tripartite synapses and cell migration.
Abstract Astrocytes have distinctive morphological and functional characteristics, and are found throughout the central nervous system. Astrocytes are now known to be far more than just housekeeping cells in the brain. Their functions include contributing to the formation of the blood–brain barrier, physically and metabolically supporting and communicating with neurons, regulating the formation and functions of synapses, and maintaining water homeostasis and the microenvironment in the brain. Aquaporins (AQPs) are transmembrane proteins responsible for fast water movement across cell membranes. Various subtypes of AQPs (AQP1, AQP3, AQP4, AQP5, AQP8 and AQP9) have been reported to be expressed in astrocytes, and the expressions and subcellular localizations of AQPs in astrocytes are highly correlated with both their physiological and pathophysiological functions. This review describes and summarizes the recent advances in our understanding of astrocytes and AQPs in regard to controlling water homeostasis in the brain. Findings regarding the features of different AQP subtypes, such as their expression, subcellular localization, physiological functions, and the pathophysiological roles of astrocytes are presented, with brain edema and glioma serving as two representative AQP-associated pathological conditions. The aim is to provide a better insight into the elaborate “water distribution” system in cells, exemplified by astrocytes, under normal and pathological conditions.
Collapse
|
34
|
The glymphatic system: implications for drugs for central nervous system diseases. Nat Rev Drug Discov 2022; 21:763-779. [PMID: 35948785 DOI: 10.1038/s41573-022-00500-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/22/2022] [Indexed: 12/14/2022]
Abstract
In the past decade, evidence for a fluid clearance pathway in the central nervous system known as the glymphatic system has grown. According to the glymphatic system concept, cerebrospinal fluid flows directionally through the brain and non-selectively clears the interstitium of metabolic waste. Importantly, the glymphatic system may be modulated by particular drugs such as anaesthetics, as well as by non-pharmacological factors such as sleep, and its dysfunction has been implicated in central nervous system disorders such as Alzheimer disease. Although the glymphatic system is best described in rodents, reports using multiple neuroimaging modalities indicate that a similar transport system exists in the human brain. Here, we overview the evidence for the glymphatic system and its role in disease and discuss opportunities to harness the glymphatic system therapeutically; for example, by improving the effectiveness of intrathecally delivered drugs.
Collapse
|
35
|
Virenque A, Koivisto H, Antila S, Zub E, Rooney EJ, Miszczuk D, Müller A, Stoka E, Marchi N, Alitalo K, Tanila H, Noe FM. Significance of developmental meningeal lymphatic dysfunction in experimental post-traumatic injury. Brain Behav Immun Health 2022; 23:100466. [PMID: 35694175 PMCID: PMC9184565 DOI: 10.1016/j.bbih.2022.100466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 04/24/2022] [Accepted: 04/26/2022] [Indexed: 12/01/2022] Open
Abstract
Understanding the pathological mechanisms unfolding after chronic traumatic brain injury (TBI) could reveal new therapeutic entry points. During the post-TBI sequel, the involvement of cerebrospinal fluid drainage through the meningeal lymphatic vessels was proposed. Here, we used K14-VEGFR3-Ig transgenic mice to analyze whether a developmental dysfunction of meningeal lymphatic vessels modifies post-TBI pathology. To this end, a moderate TBI was delivered by controlled cortical injury over the temporal lobe in male transgenic mice or their littermate controls. We performed MRI and a battery of behavioral tests over time to define the post-TBI trajectories. In vivo analyses were integrated by ex-vivo quantitative and morphometric examinations of the cortical lesion and glial cells. In post-TBI K14-VEGFR3-Ig mice, the recovery from motor deficits was protracted compared to littermates. This outcome is coherent with the observed slower hematoma clearance in transgenic mice during the first two weeks post-TBI. No other genotype-related behavioral differences were observed, and the volume of cortical lesions imaged by MRI in vivo, and confirmed by histology ex-vivo, were comparable in both groups. However, at the cellular level, post-TBI K14-VEGFR3-Ig mice exhibited an increased percentage of activated Iba1 microglia in the hippocampus and auditory cortex, areas that are proximal to the lesion. Although not impacting or modifying the structural brain damage and post-TBI behavior, a pre-existing dysfunction of meningeal lymphatic vessels is associated with morphological microglial activation over time, possibly representing a sub-clinical pathological imprint or a vulnerability factor. Our findings suggest that pre-existing mLV deficits could represent a possible risk factor for the overall outcome of TBI pathology. Developmental deficit in the meningeal lymphatic vessels contributes to sustain the chronic neuroinflammation and represent a susceptibility factor in TBI, despite the lack of a functional phenotype. Development and progression of TBI-related cortical lesion is not exacerbated by developmental deficit in meningeal lymphatics. Meningeal lymphatic developmental deficits result in increased neuroinflammation, suggesting a sub-clinical pathological imprint or a vulnerability factor. Congenital mLV deficit affects the interstitial fluid dynamics and the post-TBI hematoma resolution.
Collapse
Affiliation(s)
- Anaïs Virenque
- Neuroscience Center, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, 00290, Helsinki, Finland
| | - Hennariikka Koivisto
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Salli Antila
- Wihuri Research Institute and Translational Cancer Medicine Program, Biomedicum Helsinki, University of Helsinki, 00290, Helsinki, Finland
| | - Emma Zub
- Cerebrovascular and Glia Research, Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Erin Jane Rooney
- Neuroscience Center, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, 00290, Helsinki, Finland
| | - Diana Miszczuk
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Adrian Müller
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Enija Stoka
- Neuroscience Center, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, 00290, Helsinki, Finland
| | - Nicola Marchi
- Cerebrovascular and Glia Research, Institute of Functional Genomics, University of Montpellier, CNRS, INSERM, Montpellier, France
| | - Kari Alitalo
- Wihuri Research Institute and Translational Cancer Medicine Program, Biomedicum Helsinki, University of Helsinki, 00290, Helsinki, Finland
| | - Heikki Tanila
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
| | - Francesco Mattia Noe
- Neuroscience Center, Helsinki Institute of Life Science (HiLIFE), University of Helsinki, 00290, Helsinki, Finland
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, 70210, Kuopio, Finland
- Corresponding author. HiLIFE, Neuroscience Center, Helsinki University, Helsinki, Finland.
| |
Collapse
|
36
|
Khang M, Bindra RS, Mark Saltzman W. Intrathecal delivery and its applications in leptomeningeal disease. Adv Drug Deliv Rev 2022; 186:114338. [PMID: 35561835 DOI: 10.1016/j.addr.2022.114338] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2021] [Revised: 04/26/2022] [Accepted: 05/06/2022] [Indexed: 12/22/2022]
Abstract
Intrathecal delivery (IT) of opiates into the cerebrospinal fluid (CSF) for anesthesia and pain relief has been used clinically for decades, but this relatively straightforward approach of bypassing the blood-brain barrier has been underutilized for other indications because of its lack of utility in delivering small lipid-soluble drugs. However, emerging evidence suggests that IT drug delivery be an efficacious strategy for the treatment of cancers in which there is leptomeningeal spread of disease. In this review, we discuss CSF flow dynamics and CSF clearance pathways in the context of intrathecal delivery. We discuss human and animal studies of several new classes of therapeutic agents-cellular, protein, nucleic acid, and nanoparticle-based small molecules-that may benefit from IT delivery. The complexity of the CSF compartment presents several key challenges in predicting biodistribution of IT-delivered drugs. New approaches and strategies are needed that can overcome the high rates of turnover in the CSF to reach specific tissues or cellular targets.
Collapse
|
37
|
Keil SA, Braun M, O’Boyle R, Sevao M, Pedersen T, Agarwal S, Jansson D, Iliff JJ. Dynamic infrared imaging of cerebrospinal fluid tracer influx into the brain. NEUROPHOTONICS 2022; 9:031915. [PMID: 35602461 PMCID: PMC9113559 DOI: 10.1117/1.nph.9.3.031915] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 04/19/2022] [Indexed: 05/14/2023]
Abstract
Significance: The glymphatic system has been described recently as a series of perivascular channels that facilitate fluid exchange and solute clearance in the brain. Glymphatic dysfunction has been implicated in numerous pathological conditions, including Alzheimer's disease, traumatic brain injury, and stroke. Existing methods for assessing glymphatic function have been challenging: dynamic methods, such as two-photon microscopy and contrast-enhanced magnetic resonance imaging require expensive instrumentation and specific technical skills; slice-based fluorescent imaging is more readily implemented but lacks temporal resolution. Aim: To develop a straightforward and adaptable dynamic imaging approach for assessing glymphatic function in vivo in mice. Approach: Using a widely available small animal infrared (IR) imaging system (LICOR Pearl), visualization of IR cerebrospinal fluid tracer distribution over the cortical surface enables time-resolved measurement of the dynamics of glymphatic exchange. Using co-injection of IR and conventional fixable fluorescent tracers, dynamic imaging can be paired with whole-slice fluorescence imaging, permitting the quantification of glymphatic function throughout the brain as well as subsequent histological assessment. Results: These techniques were validated against one another, comparing differences between animals anesthetized with ketamine/xylazine and isoflurane. Conclusions: This technique permits sensitive dynamic imaging of glymphatic function, with the concurrent visualization of resolution of deeper structures.
Collapse
Affiliation(s)
- Samantha A. Keil
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
- University of Washington School of Medicine, Department of Psychiatry and Behavioral Sciences, Seattle, Washington, United States
| | - Molly Braun
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
- University of Washington School of Medicine, Department of Psychiatry and Behavioral Sciences, Seattle, Washington, United States
| | - Ryan O’Boyle
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
| | - Mathew Sevao
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
| | - Taylor Pedersen
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
| | - Sanjana Agarwal
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
| | - Deidre Jansson
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
- University of Washington School of Medicine, Department of Psychiatry and Behavioral Sciences, Seattle, Washington, United States
| | - Jeffrey J. Iliff
- VA Puget Sound Health Care System, VISN 20 Mental Illness Research, Education and Clinical Center (MIRECC), Seattle, Washington, United States
- University of Washington School of Medicine, Department of Psychiatry and Behavioral Sciences, Seattle, Washington, United States
- University of Washington School of Medicine, Department of Neurology, Seattle, Washington, United States
| |
Collapse
|
38
|
Lee MK, Cho SJ, Bae YJ, Kim JM. MRI-Based Demonstration of the Normal Glymphatic System in a Human Population: A Systematic Review. Front Neurol 2022; 13:827398. [PMID: 35693018 PMCID: PMC9174517 DOI: 10.3389/fneur.2022.827398] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2021] [Accepted: 04/27/2022] [Indexed: 11/23/2022] Open
Abstract
Background The glymphatic system has been described as one that facilitates the exchange between the cerebrospinal fluid (CSF) and interstitial fluid, and many recent studies have demonstrated glymphatic flow based on magnetic resonance imaging (MRI). We aim to systematically review the studies demonstrating a normal glymphatic flow in a human population using MRI and to propose a detailed glymphatic imaging protocol. Methods We searched the MEDLINE and EMBASE databases to identify studies with human participants involving MRI-based demonstrations of the normal glymphatic flow. We extracted data on the imaging sequence, imaging protocol, and the targeted anatomical structures on each study. Results According to contrast-enhanced MRI studies, peak enhancement was sequentially detected first in the CSF space, followed by the brain parenchyma, the meningeal lymphatic vessel (MLV), and, finally, the cervical lymph nodes, corresponding with glymphatic flow and explaining the drainage into the MLV. Non-contrast flow-sensitive MRI studies revealed similar glymphatic inflow from the CSF space to the brain parenchyma and efflux of exchanged fluid from the brain parenchyma to the MLV. Conclusion We may recommend T1-weighted contrast-enhanced MRI for visualizing glymphatic flow. Our result can increase understanding of the glymphatic system and may lay the groundwork for establishing central nervous system fluid dynamic theories and developing standardized imaging protocols.
Collapse
Affiliation(s)
- Min Kyoung Lee
- Department of Radiology, College of Medicine, Yeouido St. Mary's Hospital, The Catholic University of Korea, Soeul, South Korea
| | - Se Jin Cho
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
| | - Yun Jung Bae
- Department of Radiology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
- *Correspondence: Yun Jung Bae
| | - Jong-Min Kim
- Department of Neurology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, South Korea
- Jong-Min Kim
| |
Collapse
|
39
|
Piirainen P, Kokki H, Kokki M. Epidural Oxycodone for Acute Pain. Pharmaceuticals (Basel) 2022; 15:643. [PMID: 35631469 PMCID: PMC9144954 DOI: 10.3390/ph15050643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Revised: 05/16/2022] [Accepted: 05/19/2022] [Indexed: 02/01/2023] Open
Abstract
Epidural analgesia is commonly used in labour analgesia and in postoperative pain after major surgery. It is highly effective in severe acute pain, has minimal effects on foetus and newborn, may reduce postoperative complications, and enhance patient satisfaction. In epidural analgesia, low concentrations of local anaesthetics are combined with opioids. Two opioids, morphine and sufentanil, have been approved for epidural use, but there is an interest in evaluating other opioids as well. Oxycodone is one of the most commonly used opioids in acute pain management. However, data on its use in epidural analgesia are sparse. In this narrative review, we describe the preclinical and clinical data on epidural oxycodone. Early data from the 1990s suggested that the epidural administration of oxycodone may not offer any meaningful benefits over intravenous administration, but more recent clinical data show that oxycodone has advantageous pharmacokinetics after epidural administration and that epidural administration is more efficacious than intravenous administration. Further studies are needed on the safety and efficacy of continuous epidural oxycodone administration and its use in epidural admixture.
Collapse
Affiliation(s)
- Panu Piirainen
- Department of Anesthesiology, Surgery and Intensive Care, Oulu University Hospital, 90220 Oulu, Finland;
| | - Hannu Kokki
- Institute of Clinical Medicine, School of Medicine, Faculty of Health Sciences, Kuopio Campus, University of Eastern Finland, 70210 Kuopio, Finland;
| | - Merja Kokki
- Department of Anaesthesiology and Intensive Care, Kuopio University Hospital, 70210 Kuopio, Finland
| |
Collapse
|
40
|
Vacas S, Canales C, Deiner SG, Cole DJ. Perioperative Brain Health in the Older Adult: A Patient Safety Imperative. Anesth Analg 2022; 135:316-328. [PMID: 35584550 PMCID: PMC9288500 DOI: 10.1213/ane.0000000000006090] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
While people 65 years of age and older represent 16% of the population in the United States, they account for >40% of surgical procedures performed each year. Maintaining brain health after anesthesia and surgery is not only important to our patients, but it is also an increasingly important patient safety imperative for the specialty of anesthesiology. Aging is a complex process that diminishes the reserve of every organ system and often results in a patient who is vulnerable to the stress of surgery. The brain is no exception, and many older patients present with preoperative cognitive impairment that is undiagnosed. As we age, a number of changes occur in the human brain, resulting in a patient who is less resilient to perioperative stress, making older adults more susceptible to the phenotypic expression of perioperative neurocognitive disorders. This review summarizes the current scientific and clinical understanding of perioperative neurocognitive disorders and recommends patient-centered, age-focused interventions that can better mitigate risk, prevent harm, and improve outcomes for our patients. Finally, it discusses the emerging topic of sleep and cognitive health and other future frontiers of scientific inquiry that might inform clinical best practices.
Collapse
Affiliation(s)
- Susana Vacas
- From the Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Cecilia Canales
- From the Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| | - Stacie G Deiner
- Department of Anesthesiology, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire
| | - Daniel J Cole
- From the Department of Anesthesiology and Perioperative Medicine, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, California
| |
Collapse
|
41
|
Roy B, Nunez A, Aysola RS, Kang DW, Vacas S, Kumar R. Impaired Glymphatic System Actions in Obstructive Sleep Apnea Adults. Front Neurosci 2022; 16:884234. [PMID: 35600625 PMCID: PMC9120580 DOI: 10.3389/fnins.2022.884234] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2022] [Accepted: 04/19/2022] [Indexed: 12/20/2022] Open
Abstract
Study Objectives Obstructive sleep apnea (OSA) is accompanied by sleep fragmentation and altered sleep architecture, which can potentially hinder the glymphatic system, increasing risks for Alzheimer's disease (AD), but the status is unclear in OSA. Our aim was to investigate the glymphatic system in OSA subjects and examine the relationships between OSA disease severity, sleep symptoms, and glymphatic system indices in OSA using diffusion tensor imaging (DTI). Methods We acquired DTI data from 59 OSA and 62 controls using a 3.0-Tesla MRI and examined OSA disease severity and sleep symptoms with the Pittsburgh Sleep Quality Index (PSQI) and Epworth Sleepiness Scale (ESS). Diffusivity maps in the x-axis (Dxx), y-axis (Dyy), and z-axis (Dzz), as well as in x-y axis (Dxy), y-z axis (Dyz), and x-z axis (Dxz) were calculated, diffusion values for the projection and association fibers extracted, and the DTI analyses along the perivascular space (DTI-ALPS index) were performed. The glymphatic system indices were compared between groups and correlated with disease severity and sleep symptoms in OSA subjects. Results Dzz values, derived from projection fiber areas, Dyy and Dzz values from association fiber areas, as well as ALPS and Dyzmean values were significantly reduced in OSA over controls. Significant correlations emerged between disease severity, sleep symptoms, and Dxy, Dxx, and Dzz values in OSA subjects. Conclusion OSA patients show abnormal glymphatic system function that may contribute to increased risks for AD. The findings suggest that the APLS method can be used to assess the glymphatic system in OSA patients.
Collapse
Affiliation(s)
- Bhaswati Roy
- Department of Anesthesiology and Perioperative Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Alba Nunez
- Department of Anesthesiology and Perioperative Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Ravi S. Aysola
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Daniel W. Kang
- Department of Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Susana Vacas
- Department of Anesthesiology and Perioperative Medicine, University of California, Los Angeles, Los Angeles, CA, United States
| | - Rajesh Kumar
- Department of Anesthesiology and Perioperative Medicine, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Radiology, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Bioengineering, University of California, Los Angeles, Los Angeles, CA, United States
- Brain Research Institute, University of California, Los Angeles, Los Angeles, CA, United States
| |
Collapse
|
42
|
Eshtiaghi A, Eapen-John D, Zaslavsky K, Vosoughi R, Murray BJ, Margolin E. Sleep Quality in Neuromyelitis Optica Spectrum Disorder: A Systematic Review. Int J MS Care 2022; 24:124-131. [PMID: 35645625 PMCID: PMC9135364 DOI: 10.7224/1537-2073.2021-019] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
BACKGROUND This review summarizes the literature on sleep quality in neuromyelitis optica spectrum disorder (NMOSD) and discusses these findings in the context of current knowledge of sleep physiology. METHODS A literature search was performed using Ovid MEDLINE, Embase, and Scopus from inception to September 3, 2020. All included studies reported at least 1 measure of sleep quality in individuals with NMOSD. Pittsburgh Sleep Quality Index (PSQI) scores of individuals from 4 studies were compared with those from a data set of controls. RESULTS Thirteen studies (1041 individuals with NMOSD) were included in the review. Disturbed sleep was demonstrated across subjective metrics based on patient surveys and objective metrics such as polysomnography. An estimated 70% of individuals with NMOSD can be classified as poor sleepers. Standardized mean difference between PSQI scores of 183 individuals with NMOSD and those of 9284 controls was 0.72 (95% CI, 0.57-0.86; P < .001). Decreased sleep quality was significantly associated with decreased quality of life and increased anxiety, depression, and disability status. Sleep disturbances in NMOSD were similar in severity to those in multiple sclerosis. CONCLUSIONS Sleep disturbances are a major contributor to NMOSD disease burden and may arise from the disruption of sleep circuitry, in addition to physical and psychological complications. Multiple processes involved in sleep regulation may be affected, such as, but not limited to, neural circadian circuit disruption, direct effects of inflammation, aminergic projecting system abnormalities, glymphatic system impairment, and development of sleep disorders such as restless legs syndrome/sleep apnea. A better understanding of these mechanisms is necessary for developing effective therapies for NMOSD-associated sleep disturbances.
Collapse
Affiliation(s)
- Arshia Eshtiaghi
- From the Faculty of Medicine (AE, DE-J), University of Toronto, Toronto, ON, Canada
| | - David Eapen-John
- From the Faculty of Medicine (AE, DE-J), University of Toronto, Toronto, ON, Canada
| | - Kirill Zaslavsky
- From the Department of Ophthalmology and Vision Sciences (KZ, EM), University of Toronto, Toronto, ON, Canada
| | - Reza Vosoughi
- From the Division of Neurology, Department of Medicine (RV, BJM), University of Toronto, Toronto, ON, Canada
- From the St Michael’s Hospital, Toronto, ON, Canada (RV)
| | - Brian J. Murray
- From the Division of Neurology, Department of Medicine (RV, BJM), University of Toronto, Toronto, ON, Canada
- From the Sunnybrook Health Science Centre, Toronto, ON, Canada (BJM)
| | - Edward Margolin
- From the Department of Ophthalmology and Vision Sciences (KZ, EM), University of Toronto, Toronto, ON, Canada
| |
Collapse
|
43
|
Maki KA, Alkhatib J, Butera G, Wallen GR. Examining Relationships between Sleep Physiology and the Gut Microbiome in Pre-Clinical and Translational Research: A Scoping Review Protocol (Preprint). JMIR Res Protoc 2022; 11:e38605. [PMID: 35727619 PMCID: PMC9257612 DOI: 10.2196/38605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/13/2022] [Accepted: 06/05/2022] [Indexed: 11/13/2022] Open
Abstract
Background Objective Methods Results Conclusions Trial Registration International Registered Report Identifier (IRRID)
Collapse
Affiliation(s)
- Katherine Anne Maki
- Translational Biobehavioral and Health Disparities Branch, National Institutes of Health Clinical Center, Bethesda, MD, United States
| | - Jenna Alkhatib
- Translational Biobehavioral and Health Disparities Branch, National Institutes of Health Clinical Center, Bethesda, MD, United States
| | - Gisela Butera
- Division of Library Services, National Institutes of Health, Bethesda, MD, United States
| | - Gwenyth Reid Wallen
- Translational Biobehavioral and Health Disparities Branch, National Institutes of Health Clinical Center, Bethesda, MD, United States
| |
Collapse
|
44
|
Abstract
The brain harbors a unique ability to, figuratively speaking, shift its gears. During wakefulness, the brain is geared fully toward processing information and behaving, while homeostatic functions predominate during sleep. The blood-brain barrier establishes a stable environment that is optimal for neuronal function, yet the barrier imposes a physiological problem; transcapillary filtration that forms extracellular fluid in other organs is reduced to a minimum in brain. Consequently, the brain depends on a special fluid [the cerebrospinal fluid (CSF)] that is flushed into brain along the unique perivascular spaces created by astrocytic vascular endfeet. We describe this pathway, coined the term glymphatic system, based on its dependency on astrocytic vascular endfeet and their adluminal expression of aquaporin-4 water channels facing toward CSF-filled perivascular spaces. Glymphatic clearance of potentially harmful metabolic or protein waste products, such as amyloid-β, is primarily active during sleep, when its physiological drivers, the cardiac cycle, respiration, and slow vasomotion, together efficiently propel CSF inflow along periarterial spaces. The brain's extracellular space contains an abundance of proteoglycans and hyaluronan, which provide a low-resistance hydraulic conduit that rapidly can expand and shrink during the sleep-wake cycle. We describe this unique fluid system of the brain, which meets the brain's requisites to maintain homeostasis similar to peripheral organs, considering the blood-brain-barrier and the paths for formation and egress of the CSF.
Collapse
Affiliation(s)
- Martin Kaag Rasmussen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Humberto Mestre
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, New York
| |
Collapse
|
45
|
Li L, Ding G, Zhang L, Davoodi-Bojd E, Chopp M, Li Q, Zhang ZG, Jiang Q. Aging-Related Alterations of Glymphatic Transport in Rat: In vivo Magnetic Resonance Imaging and Kinetic Study. Front Aging Neurosci 2022; 14:841798. [PMID: 35360203 PMCID: PMC8960847 DOI: 10.3389/fnagi.2022.841798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2021] [Accepted: 02/18/2022] [Indexed: 11/23/2022] Open
Abstract
Objective Impaired glymphatic waste clearance function during brain aging leads to the accumulation of metabolic waste and neurotoxic proteins (e.g., amyloid-β, tau) which contribute to neurological disorders. However, how the age-related glymphatic dysfunction exerts its effects on different cerebral regions and affects brain waste clearance remain unclear. Methods We investigated alterations of glymphatic transport in the aged rat brain using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and advanced kinetic modeling. Healthy young (3-4 months) and aged (18-20 months) male rats (n = 12/group) underwent the identical MRI protocol, including T2-weighted imaging and 3D T1-weighted imaging with intracisternal administration of contrast agent (Gd-DTPA). Model-derived parameters of infusion rate and clearance rate, characterizing the kinetics of cerebrospinal fluid (CSF) tracer transport via the glymphatic system, were evaluated in multiple representative brain regions. Changes in the CSF-filled cerebral ventricles were measured using contrast-induced time signal curves (TSCs) in conjunction with structural imaging. Results Compared to the young brain, an overall impairment of glymphatic transport function was detected in the aged brain, evidenced by the decrease in both infusion and clearance rates throughout the brain. Enlarged ventricles in parallel with reduced efficiency in CSF transport through the ventricular regions were present in the aged brain. While the age-related glymphatic dysfunction was widespread, our kinetic quantification demonstrated that its impact differed considerably among cerebral regions with the most severe effect found in olfactory bulb, indicating the heterogeneous and regional preferential alterations of glymphatic function. Conclusion The robust suppression of glymphatic activity in the olfactory bulb, which serves as one of major efflux routes for brain waste clearance, may underlie, in part, age-related neurodegenerative diseases associated with neurotoxic substance accumulation. Our data provide new insight into the cerebral regional vulnerability to brain functional change with aging.
Collapse
Affiliation(s)
- Lian Li
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | | | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
- Department of Physics, Oakland University, Rochester, MI, United States
| | - Qingjiang Li
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Zheng Gang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI, United States
| |
Collapse
|
46
|
Salehpour F, Khademi M, Bragin DE, DiDuro JO. Photobiomodulation Therapy and the Glymphatic System: Promising Applications for Augmenting the Brain Lymphatic Drainage System. Int J Mol Sci 2022; 23:ijms23062975. [PMID: 35328396 PMCID: PMC8950470 DOI: 10.3390/ijms23062975] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Revised: 01/21/2022] [Accepted: 01/22/2022] [Indexed: 12/21/2022] Open
Abstract
The glymphatic system is a glial-dependent waste clearance pathway in the central nervous system, devoted to drain away waste metabolic products and soluble proteins such as amyloid-beta. An impaired brain glymphatic system can increase the incidence of neurovascular, neuroinflammatory, and neurodegenerative diseases. Photobiomodulation (PBM) therapy can serve as a non-invasive neuroprotective strategy for maintaining and optimizing effective brain waste clearance. In this review, we discuss the crucial role of the glymphatic drainage system in removing toxins and waste metabolites from the brain. We review recent animal research on the neurotherapeutic benefits of PBM therapy on glymphatic drainage and clearance. We also highlight cellular mechanisms of PBM on the cerebral glymphatic system. Animal research has shed light on the beneficial effects of PBM on the cerebral drainage system through the clearance of amyloid-beta via meningeal lymphatic vessels. Finally, PBM-mediated increase in the blood–brain barrier permeability with a subsequent rise in Aβ clearance from PBM-induced relaxation of lymphatic vessels via a vasodilation process will be discussed. We conclude that PBM promotion of cranial and extracranial lymphatic system function might be a promising strategy for the treatment of brain diseases associated with cerebrospinal fluid outflow abnormality.
Collapse
Affiliation(s)
- Farzad Salehpour
- College for Light Medicine and Photobiomodulation, D-82319 Starnberg, Germany;
- ProNeuroLIGHT LLC, Phoenix, AZ 85041, USA
| | - Mahsa Khademi
- Neurosciences Research Center (NSRC), Tabriz University of Medical Sciences, Tabriz 51666, Iran;
| | - Denis E. Bragin
- Department of Neurology, University of New Mexico School of Medicine, Albuquerque, NM 87131, USA;
| | - Joseph O. DiDuro
- ProNeuroLIGHT LLC, Phoenix, AZ 85041, USA
- Correspondence: ; Tel.: +1-(845)-203-9204
| |
Collapse
|
47
|
Siow TY, Toh CH, Hsu JL, Liu GH, Lee SH, Chen NH, Fu CJ, Castillo M, Fang JT. Association of Sleep, Neuropsychological Performance, and Gray Matter Volume With Glymphatic Function in Community-Dwelling Older Adults. Neurology 2022; 98:e829-e838. [PMID: 34906982 DOI: 10.1212/wnl.0000000000013215] [Citation(s) in RCA: 45] [Impact Index Per Article: 22.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2021] [Accepted: 12/02/2021] [Indexed: 11/15/2022] Open
Abstract
BACKGROUND AND OBJECTIVES The glymphatic system, which is robustly enabled during some stages of sleep, is a fluid-transport pathway that clears cerebral waste products. Most contemporary knowledge regarding the glymphatic system is inferred from rodent experiments and human research is limited. Our objective is to explore the associations between human glymphatic function, sleep, neuropsychological performance, and cerebral gray matter volumes. METHODS This cross-sectional study included individuals 60 years or older who had participated in the Integrating Systemic Data of Geriatric Medicine to Explore the Solution for Health Aging study between September 2019 and October 2020. Community-dwelling older adults were enrolled at 2 different sites. Participants with dementia, major depressive disorders, and other major organ system abnormalities were excluded. Sleep profile was accessed using questionnaires and polysomnography. Administered neuropsychological test batteries included Everyday Cognition (ECog) and the Consortium to Establish a Registry for Alzheimer's Disease Neuropsychological Battery (CERAD-NB). Gray matter volumes were estimated based on MRI. Diffusion tensor imaging analysis along the perivascular space (DTI-ALPS) index was used as the MRI marker of glymphatic function. RESULTS A total of 84 participants (mean [SD] age 73.3 [7.1] years, 47 [56.0%] women) were analyzed. Multivariate linear regression model determined that age (unstandardized β, -0.0025 [SE 0.0001]; p = 0.02), N2 sleep duration (unstandardized β, 0.0002 [SE 0.0001]; p = 0.04), and the apnea-hypopnea index (unstandardized β, -0.0011 [SE 0.0005]; p = 0.03) were independently associated with DTI-ALPS. Higher DTI-ALPS was associated with better ECog language scores (unstandardized β, -0.59 [SE 0.28]; p = 0.04) and better CERAD-NB word list learning delayed recall subtest scores (unstandardized β, 6.17 [SE 2.31]; p = 0.009) after covarying for age and education. Higher DTI-ALPS was also associated with higher gray matter volume (unstandardized β, 107.00 [SE 43.65]; p = 0.02) after controlling for age, sex, and total intracranial volume. DISCUSSION Significant associations were identified between glymphatic function and sleep, stressing the importance of sleep for brain health. This study also revealed associations between DTI-ALPS, neuropsychological performance, and cerebral gray matter volumes, suggesting the potential of DTI-ALPS as a biomarker for cognitive disorders.
Collapse
Affiliation(s)
- Tiing Yee Siow
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| | - Cheng Hong Toh
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill.
| | - Jung-Lung Hsu
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| | - Geng-Hao Liu
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| | - Shwu-Hua Lee
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| | - Ning-Hung Chen
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| | - Changjui James Fu
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| | - Mauricio Castillo
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| | - Ji-Tseng Fang
- From the Department of Medical Imaging and Intervention (T.Y.S., C.H.T.) and Neuroscience Research Center, Department of Neurology, Medical Center and College of Medicine (J.-L.H.), Chang Gung University College of Medicine, and Division of Acupuncture and Moxibustion, Department of Traditional Chinese Medicine (G.-H.L.), Department of Psychiatry (S.-H.L.), Department of Pulmonary and Critical Care Medicine (N.-H.C.), Biomedical Informatics Unit, Clinical Trial Center (C.J.F.), and Department of Nephrology (J.-T.F.), Chang Gung Memorial Hospital at Linkou, Taoyuan; Graduate Institute of Mind, Brain, & Consciousness (J.-L.H.), Taipei Medical University; Brain & Consciousness Research Center (J.-L.H.), Shuang Ho Hospital, New Taipei City; School of Traditional Chinese Medicine (G.-H.L., N.-H.C.) and School of Medicine (J.-T.F.), College of Medicine (S.-H.L.), Chang Gung University; Sleep Center (G.-H.L., N.-H.C.), Chang Gung Memorial Hospital, Taoyuan, Taiwan; and Department of Radiology (M.C.), University of North Carolina School of Medicine, Chapel Hill
| |
Collapse
|
48
|
Hladky SB, Barrand MA. The glymphatic hypothesis: the theory and the evidence. Fluids Barriers CNS 2022; 19:9. [PMID: 35115036 PMCID: PMC8815211 DOI: 10.1186/s12987-021-00282-z] [Citation(s) in RCA: 87] [Impact Index Per Article: 43.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 10/15/2021] [Indexed: 12/13/2022] Open
Abstract
The glymphatic hypothesis proposes a mechanism for extravascular transport into and out of the brain of hydrophilic solutes unable to cross the blood-brain barrier. It suggests that there is a circulation of fluid carrying solutes inwards via periarterial routes, through the interstitium and outwards via perivenous routes. This review critically analyses the evidence surrounding the mechanisms involved in each of these stages. There is good evidence that both influx and efflux of solutes occur along periarterial routes but no evidence that the principal route of outflow is perivenous. Furthermore, periarterial inflow of fluid is unlikely to be adequate to provide the outflow that would be needed to account for solute efflux. A tenet of the hypothesis is that flow sweeps solutes through the parenchyma. However, the velocity of any possible circulatory flow within the interstitium is too small compared to diffusion to provide effective solute movement. By comparison the earlier classical hypothesis describing extravascular transport proposed fluid entry into the parenchyma across the blood-brain barrier, solute movements within the parenchyma by diffusion, and solute efflux partly by diffusion near brain surfaces and partly carried by flow along "preferred routes" including perivascular spaces, white matter tracts and subependymal spaces. It did not suggest fluid entry via periarterial routes. Evidence is still incomplete concerning the routes and fate of solutes leaving the brain. A large proportion of the solutes eliminated from the parenchyma go to lymph nodes before reaching blood but the proportions delivered directly to lymph or indirectly via CSF which then enters lymph are as yet unclear. In addition, still not understood is why and how the absence of AQP4 which is normally highly expressed on glial endfeet lining periarterial and perivenous routes reduces rates of solute elimination from the parenchyma and of solute delivery to it from remote sites of injection. Neither the glymphatic hypothesis nor the earlier classical hypothesis adequately explain how solutes and fluid move into, through and out of the brain parenchyma. Features of a more complete description are discussed. All aspects of extravascular transport require further study.
Collapse
Affiliation(s)
- Stephen B. Hladky
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| | - Margery A. Barrand
- Department of Pharmacology, University of Cambridge, Cambridge, CB2 1PD UK
| |
Collapse
|
49
|
Chong PLH, Garic D, Shen MD, Lundgaard I, Schwichtenberg AJ. Sleep, cerebrospinal fluid, and the glymphatic system: A systematic review. Sleep Med Rev 2022; 61:101572. [PMID: 34902819 PMCID: PMC8821419 DOI: 10.1016/j.smrv.2021.101572] [Citation(s) in RCA: 35] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 10/14/2021] [Accepted: 11/10/2021] [Indexed: 02/03/2023]
Abstract
Current theories of the glymphatic system (GS) hypothesize that it relies on cerebrospinal fluid (CSF) circulation to disseminate growth factors and remove metabolic waste from the brain with increased CSF production and circulation during sleep; thereby, linking sleep disturbance with elements of CSF circulation and GS exchange. However, our growing knowledge of the relations between sleep, CSF, and the GS are plagued by variability in sleep and CSF measures across a wide array of pathologies. Hence, this review aims to summarize the dynamic relationships between sleep, CSF-, and GS-related features in samples of typically developing individuals and those with autoimmune/inflammatory, neurodegenerative, neurodevelopmental, sleep-related, neurotraumatic, neuropsychiatric, and skull atypicalities. One hundred and ninety articles (total n = 19,129 participants) were identified and reviewed for pathology, CSF circulation and related metrics, GS function, and sleep. Numerous associations were documented between sleep problems and CSF metabolite concentrations (e.g., amyloid-beta, orexin, tau proteins) and increased CSF volumes or pressure. However, these relations were not universal, with marked differences across pathologies. It is clear that elements of CSF circulation/composition and GS exchange represent pathways influenced by sleep; however, carefully designed studies and advances in GS measurement are needed to delineate the nuanced relationships.
Collapse
Affiliation(s)
| | - D. Garic
- University of North Carolina, Chapel Hill, NC
| | - M. D. Shen
- University of North Carolina, Chapel Hill, NC
| | - I. Lundgaard
- Department of Experimental Medicine Science, Lund University, Lund, Sweden,Wallenberg Center for Molecular Medicine, Lund University, Lund, Sweden
| | | |
Collapse
|
50
|
Albayram MS, Smith G, Tufan F, Tuna IS, Bostancıklıoğlu M, Zile M, Albayram O. Non-invasive MR imaging of human brain lymphatic networks with connections to cervical lymph nodes. Nat Commun 2022; 13:203. [PMID: 35017525 PMCID: PMC8752739 DOI: 10.1038/s41467-021-27887-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 33.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 12/21/2021] [Indexed: 12/15/2022] Open
Abstract
Meningeal lymphatic vessels have been described in animal studies, but limited comparable data is available in human studies. Here we show dural lymphatic structures along the dural venous sinuses in dorsal regions and along cranial nerves in the ventral regions in the human brain. 3D T2-Fluid Attenuated Inversion Recovery magnetic resonance imaging relies on internal signals of protein rich lymphatic fluid rather than contrast media and is used in the present study to visualize the major human dural lymphatic structures. Moreover we detect direct connections between lymphatic fluid channels along the cranial nerves and vascular structures and the cervical lymph nodes. We also identify age-related cervical lymph node atrophy and thickening of lymphatics channels in both dorsal and ventral regions, findings which reflect the reduced lymphatic output of the aged brain.
Collapse
Affiliation(s)
- Mehmet Sait Albayram
- Department of Radiology, University of Florida, College of Medicine, Gainesville, FL, 32610, USA.
| | - Garrett Smith
- Department of Radiology, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Fatih Tufan
- Geriatrician (PP), Silivrikapi Mh. Hisaralti Cd, Istanbul, 34093, Turkey
| | - Ibrahim Sacit Tuna
- Department of Radiology, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | | | - Michael Zile
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
- Division of Cardiology, Department of Medicine, Ralph H. Johnson Department of Veterans Affairs Medical Center, Charleston, SC, 29425, USA
| | - Onder Albayram
- Division of Cardiology, Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, 29425, USA
- Hollings Cancer Center, Medical University of South Carolina, Charleston, SC, 29425, USA
| |
Collapse
|