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van Veluw SJ, Benveniste H, Bakker ENTP, Carare RO, Greenberg SM, Iliff JJ, Lorthois S, Van Nostrand WE, Petzold GC, Shih AY, van Osch MJP. Is CAA a perivascular brain clearance disease? A discussion of the evidence to date and outlook for future studies. Cell Mol Life Sci 2024; 81:239. [PMID: 38801464 PMCID: PMC11130115 DOI: 10.1007/s00018-024-05277-1] [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: 11/14/2023] [Revised: 04/20/2024] [Accepted: 05/13/2024] [Indexed: 05/29/2024]
Abstract
The brain's network of perivascular channels for clearance of excess fluids and waste plays a critical role in the pathogenesis of several neurodegenerative diseases including cerebral amyloid angiopathy (CAA). CAA is the main cause of hemorrhagic stroke in the elderly, the most common vascular comorbidity in Alzheimer's disease and also implicated in adverse events related to anti-amyloid immunotherapy. Remarkably, the mechanisms governing perivascular clearance of soluble amyloid β-a key culprit in CAA-from the brain to draining lymphatics and systemic circulation remains poorly understood. This knowledge gap is critically important to bridge for understanding the pathophysiology of CAA and accelerate development of targeted therapeutics. The authors of this review recently converged their diverse expertise in the field of perivascular physiology to specifically address this problem within the framework of a Leducq Foundation Transatlantic Network of Excellence on Brain Clearance. This review discusses the overarching goal of the consortium and explores the evidence supporting or refuting the role of impaired perivascular clearance in the pathophysiology of CAA with a focus on translating observations from rodents to humans. We also discuss the anatomical features of perivascular channels as well as the biophysical characteristics of fluid and solute transport.
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Affiliation(s)
- Susanne J van Veluw
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Erik N T P Bakker
- Department of Biomedical Engineering, Amsterdam University Medical Center, Location AMC, Amsterdam Neuroscience Research Institute, Amsterdam, The Netherlands
| | - Roxana O Carare
- Clinical Neurosciences, University of Southampton, Southampton, UK
| | - Steven M Greenberg
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Jeffrey J Iliff
- VA Puget Sound Health Care System, University of Washington, Seattle, WA, USA
| | - Sylvie Lorthois
- Institut de Mécanique Des Fluides de Toulouse, IMFT, Université de Toulouse, CNRS, Toulouse, France
| | - William E Van Nostrand
- Department of Biomedical and Pharmaceutical Science, George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, USA
| | - Gabor C Petzold
- German Center for Neurodegenerative Disease, Bonn, Germany
- Division of Vascular Neurology, Department of Neurology, University Hospital Bonn, Bonn, Germany
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, University of Washington, Seattle, WA, USA
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2
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Miao A, Luo T, Hsieh B, Edge CJ, Gridley M, Wong RTC, Constandinou TG, Wisden W, Franks NP. Brain clearance is reduced during sleep and anesthesia. Nat Neurosci 2024:10.1038/s41593-024-01638-y. [PMID: 38741022 DOI: 10.1038/s41593-024-01638-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 04/03/2024] [Indexed: 05/16/2024]
Abstract
It has been suggested that the function of sleep is to actively clear metabolites and toxins from the brain. Enhanced clearance is also said to occur during anesthesia. Here, we measure clearance and movement of fluorescent molecules in the brains of male mice and show that movement is, in fact, independent of sleep and wake or anesthesia. Moreover, we show that brain clearance is markedly reduced, not increased, during sleep and anesthesia.
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Affiliation(s)
- Andawei Miao
- Department of Life Sciences, Imperial College London, South Kensington, London, UK
- UK Dementia Research Institute, Imperial College London, London, UK
| | - Tianyuan Luo
- Department of Life Sciences, Imperial College London, South Kensington, London, UK
- Department of Anesthesiology, Affiliated Hospital of Zunyi Medical University, Zunyi, China
- Guizhou Key Laboratory of Anesthesia and Organ Protection, Zunyi Medical University, Zunyi, China
| | - Bryan Hsieh
- Department of Life Sciences, Imperial College London, South Kensington, London, UK
- Centre for Doctoral Training and Centre for Neurotechnology, Imperial College London, London, UK
| | - Christopher J Edge
- Department of Life Sciences, Imperial College London, South Kensington, London, UK
| | - Morgan Gridley
- Department of Life Sciences, Imperial College London, South Kensington, London, UK
| | - Ryan Tak Chun Wong
- Department of Life Sciences, Imperial College London, South Kensington, London, UK
| | - Timothy G Constandinou
- Department of Electrical and Electronic Engineering and UK Dementia Research Institute, Care Research & Technology, Imperial College London, London, UK
| | - William Wisden
- Department of Life Sciences, Imperial College London, South Kensington, London, UK.
- UK Dementia Research Institute, Imperial College London, London, UK.
- Centre for Doctoral Training and Centre for Neurotechnology, Imperial College London, London, UK.
| | - Nicholas P Franks
- Department of Life Sciences, Imperial College London, South Kensington, London, UK.
- UK Dementia Research Institute, Imperial College London, London, UK.
- Centre for Doctoral Training and Centre for Neurotechnology, Imperial College London, London, UK.
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3
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Eide PK, Ringstad G. Glymphatic-stagnated edema induced by traumatic brain injury. Trends Pharmacol Sci 2024; 45:388-390. [PMID: 38290921 DOI: 10.1016/j.tips.2024.01.005] [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: 12/20/2023] [Revised: 01/11/2024] [Accepted: 01/17/2024] [Indexed: 02/01/2024]
Abstract
Traumatic brain injury (TBI) outcomes are notably affected by brain edema. A recent report by Hussain et al. unveils a unique form, glymphatic-stagnated brain edema, that stems from impaired glymphatic and lymphatic drainage induced by noradrenergic activation. Consequently, pan-noradrenergic inhibition may emerge as an innovative treatment for TBI-related edema, challenging traditional therapeutic approaches.
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Affiliation(s)
- Per Kristian Eide
- Department of Neurosurgery, Oslo University Hospital - Rikshospitalet, Oslo, Norway; Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway.
| | - Geir Ringstad
- Department of Radiology, Oslo University Hospital - Rikshospitalet, Oslo, Norway; Department of Geriatrics and Internal medicine, Sorlandet Hospital, Arendal, Norway
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4
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Sun B, Fang D, Li W, Li M, Zhu S. NIR-II nanoprobes for investigating the glymphatic system function under anesthesia and stroke injury. J Nanobiotechnology 2024; 22:200. [PMID: 38654299 DOI: 10.1186/s12951-024-02481-w] [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: 01/14/2024] [Accepted: 04/16/2024] [Indexed: 04/25/2024] Open
Abstract
The glymphatic system plays an important role in the transportation of cerebrospinal fluid (CSF) and the clearance of metabolite waste in brain. However, current imaging modalities for studying the glymphatic system are limited. Herein, we apply NIR-II nanoprobes with non-invasive and high-contrast advantages to comprehensively explore the function of glymphatic system in mice under anesthesia and cerebral ischemia-reperfusion injury conditions. Our results show that the supplement drug dexmedetomidine (Dex) enhances CSF influx in the brain, decreases its outflow to mandibular lymph nodes, and leads to significant differences in CSF accumulation pattern in the spine compared to isoflurane (ISO) alone, while both ISO and Dex do not affect the clearance of tracer-filled CSF into blood circulation. Notably, we confirm the compromised glymphatic function after cerebral ischemia-reperfusion injury, leading to impaired glymphatic influx and reduced glymphatic efflux. This technique has great potential to elucidate the underlying mechanisms between the glymphatic system and central nervous system diseases.
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Affiliation(s)
- Bin Sun
- Joint Laboratory of Opto-Functional Theranostics in Medicine and Chemistry, First Hospital of Jilin University, Changchun, 130021, China
- State Key Laboratory of Supramolecular Structure and Materials, Center for Supramolecular Chemical Biology, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Danlan Fang
- Joint Laboratory of Opto-Functional Theranostics in Medicine and Chemistry, First Hospital of Jilin University, Changchun, 130021, China
- State Key Laboratory of Supramolecular Structure and Materials, Center for Supramolecular Chemical Biology, College of Chemistry, Jilin University, Changchun, 130012, China
| | - Wenzhong Li
- Joint Laboratory of Opto-Functional Theranostics in Medicine and Chemistry, First Hospital of Jilin University, Changchun, 130021, China
| | - Mengfei Li
- Joint Laboratory of Opto-Functional Theranostics in Medicine and Chemistry, First Hospital of Jilin University, Changchun, 130021, China
| | - Shoujun Zhu
- Joint Laboratory of Opto-Functional Theranostics in Medicine and Chemistry, First Hospital of Jilin University, Changchun, 130021, China.
- State Key Laboratory of Supramolecular Structure and Materials, Center for Supramolecular Chemical Biology, College of Chemistry, Jilin University, Changchun, 130012, China.
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5
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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.
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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
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6
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Wen Q, Wang H, Haacke EM, Jiang Q, Hu J. Contribution of Direct Cerebral Vascular Transport in Brain Substance Clearance. Aging Dis 2024; 15:584-600. [PMID: 37611901 PMCID: PMC10917538 DOI: 10.14336/ad.2023.0426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 04/26/2023] [Indexed: 08/25/2023] Open
Abstract
The accumulation of harmful substances has long been recognized as a likely cause of many neurodegenerative diseases. The two classic brain clearance pathways are cerebrospinal fluid (CSF) and vascular circulation systems. Since the discovery of the glymphatic system, research on the CSF pathway has gained momentum, and impaired CSF clearance has been implicated in virtually all neurodegenerative animal models. However, the contribution of the direct participation of vascular transport across the blood-brain barrier in clearing substances is often ignored in glymphatic papers. Supportive evidence for the direct involvement of parenchymal vasculature in substance clearance is accumulated. First, multiple mechanisms have been proposed for the vascular drainage of exogenous and endogenous substances across the blood-brain barriers. Second, the "traditional" role of arachnoid villi and granulations as the main site for CSF draining into the vasculature system has been questioned. Third, MRI studies using different CSF tracers indicate that parenchymal vasculature directly participates in tracer efflux, consistent with immunohistochemical findings. Here we will review evidence in the literature that supports the direct participation of the parenchymal vascular system in substance clearance, in addition to the CSF clearance pathways.
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Affiliation(s)
- Qiuting Wen
- Department of Radiology and Imaging Sciences, Indiana University, Indianapolis, IN, USA.
| | - Haoyu Wang
- Beijing Institute of Radiation Medicine, Beijing, China.
| | - E. Mark Haacke
- Department of Radiology, Wayne State University, Detroit, MI 48201 USA.
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202 USA.
| | - Jiani Hu
- Department of Radiology, Wayne State University, Detroit, MI 48201 USA.
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7
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Kaur J, Boyd ED, Ding G, Zhang L, Luo H, Li Q, Li L, Wei M, Landschoot-Ward J, Chopp M, Zhang Z, Jiang Q. The Association between Glymphatic System and Perivascular Macrophages in Brain Waste Clearance. Diagnostics (Basel) 2024; 14:731. [PMID: 38611644 PMCID: PMC11011895 DOI: 10.3390/diagnostics14070731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2024] [Revised: 03/13/2024] [Accepted: 03/14/2024] [Indexed: 04/14/2024] Open
Abstract
The glymphatic system suggests the convective bulk flow of cerebrospinal fluid (CSF) through perivascular spaces and the interstitial spaces of the brain parenchyma for the rapid removal of toxic waste solutes from the brain. However, the presence of convective bulk flow within the brain interstitial spaces is still under debate. We first addressed this argument to determine the involvement of the glymphatic system in brain waste clearance utilizing contrast-enhanced 3D T1-weighted imaging (T1WI), diffusion tensor imaging (DTI), and confocal microscopy imaging. Furthermore, perivascular macrophages (PVMs), which are immune cells located within perivascular spaces, have not been thoroughly explored for their association with the glymphatic system. Therefore, we investigated tracer uptake by PVMs in the perivascular spaces of both the arteries/arterioles and veins/venules and the potential association of PVMs in assisting the glymphatic system for interstitial waste clearance. Our findings demonstrated that both convective bulk flow and diffusion are responsible for the clearance of interstitial waste solutes from the brain parenchyma. Furthermore, our results suggested that PVMs may play an important function in glymphatic system-mediated interstitial waste clearance. The glymphatic system and PVMs could be targeted to enhance interstitial waste clearance in patients with waste-associated neurological conditions and aging.
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Affiliation(s)
- Jasleen Kaur
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
| | - Edward D. Boyd
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
| | - Hao Luo
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Qingjiang Li
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Lian Li
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Min Wei
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Julie Landschoot-Ward
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
- Department of Neurology, Wayne State University, Detroit, MI 48202, USA
| | - Zhenggang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA
- Department of Neurology, Wayne State University, Detroit, MI 48202, USA
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI 48202, USA; (J.K.); (E.D.B.); (G.D.); (L.Z.); (H.L.); (Q.L.); (L.L.); (M.W.); (J.L.-W.); (M.C.); (Z.Z.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
- Department of Neurology, Wayne State University, Detroit, MI 48202, USA
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8
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Boyd ED, Kaur J, Ding G, Chopp M, Jiang Q. Clinical magnetic resonance imaging evaluation of glymphatic function. NMR IN BIOMEDICINE 2024:e5132. [PMID: 38465514 DOI: 10.1002/nbm.5132] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 01/31/2024] [Accepted: 02/06/2024] [Indexed: 03/12/2024]
Abstract
The glymphatic system is a system of specialized perivascular spaces in the brain that facilitates removal of toxic waste solutes from the brain. Evaluation of glymphatic system function by means of magnetic resonance imaging (MRI) has thus far been largely focused on rodents because of the limitations of intrathecal delivery of gadolinium-based contrast agents to humans. This review discusses MRI methods that can be employed clinically for glymphatic-related measurements intended for early diagnosis, prevention, and the treatment of various neurological conditions. Although glymphatic system-based MRI research is in its early stages, recent studies have identified promising noninvasive MRI markers associated with glymphatic system alterations in neurological diseases. However, further optimization in data acquisition, validation, and modeling are needed to investigate the glymphatic system within the clinical setting.
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Affiliation(s)
- Edward D Boyd
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
- Department of Radiology, Michigan State University, East Lansing, Michigan, USA
| | - Jasleen Kaur
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
- Department of Physics, Oakland University, Rochester, Michigan, USA
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
- Department of Radiology, Michigan State University, East Lansing, Michigan, USA
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
- Department of Physics, Oakland University, Rochester, Michigan, USA
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, Michigan, USA
- Department of Radiology, Michigan State University, East Lansing, Michigan, USA
- Department of Physics, Oakland University, Rochester, Michigan, USA
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9
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Das N, Dhamija R, Sarkar S. The role of astrocytes in the glymphatic network: a narrative review. Metab Brain Dis 2024; 39:453-465. [PMID: 38008886 DOI: 10.1007/s11011-023-01327-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2023] [Accepted: 11/17/2023] [Indexed: 11/28/2023]
Abstract
To date, treatment of Central Nervous System (CNS) pathology has largely focused on neuronal structure and function. Yet, revived attention towards fluid circulation within the CNS has exposed the need to further explore the role of glial cells in maintaining homeostasis within neural networks. In the past decade, discovery of the neural glymphatic network has revolutionized traditional understanding of fluid dynamics within the CNS. Advancements in neuroimaging have revealed alternative pathways of cerebrospinal fluid (CSF) generation and efflux. Here, we discuss emerging perspectives on the role of astrocytes in CSF hydrodynamics, with particular focus on the contribution of aquaporin-4 channels to the glymphatic network. Astrocytic structural features and expression patterns are detailed in relation to their function in maintaining integrity of the Blood Brain Barrier (BBB) as part of the neurovascular unit (NVU). This narrative also highlights the potential role of glial dysfunction in pathogenesis of neurodegenerative disease, hydrocephalus, intracranial hemorrhage, ischemic stroke, and traumatic brain injury. The purpose of this literature summary is to provide an update on the changing landscape of scientific theory surrounding production, flow, and absorption of cerebrospinal fluid. The overarching aim of this narrative review is to advance the conception of basic, translational, and clinical research endeavors investigating glia as therapeutic targets for neurological disease.
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Affiliation(s)
- Nikita Das
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Ravi Dhamija
- Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Sumit Sarkar
- Division of Neurotoxicology, HFT-132, National Center for Toxicological Research, U.S. Food & Drug Administration, Jefferson, AR, 72079, USA.
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10
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Boyd ED, Zhang L, Ding G, Li L, Lu M, Li Q, Huang R, Kaur J, Hu J, Chopp M, Zhang Z, Jiang Q. The Glymphatic Response to the Development of Type 2 Diabetes. Biomedicines 2024; 12:401. [PMID: 38398003 PMCID: PMC10886551 DOI: 10.3390/biomedicines12020401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 01/21/2024] [Accepted: 02/02/2024] [Indexed: 02/25/2024] Open
Abstract
The glymphatic system has recently been shown to be important in neurological diseases, including diabetes. However, little is known about how the progressive onset of diabetes affects the glymphatic system. The aim of this study is to investigate the glymphatic system response to the progressive onset of diabetes in a rat model of type 2 diabetic mellitus. Male Wistar rats (n = 45) with and without diabetes were evaluated using MRI glymphatic tracer kinetics, functional tests, and brain tissue immunohistochemistry. Our data demonstrated that the contrast agent clearance impairment gradually progressed with the diabetic duration. The MRI data showed that an impairment in contrast clearance occurred prior to the cognitive deficits detected using functional tests and permitted the detection of an early DM stage compared to the immuno-histopathology and cognitive tests. Additionally, the quantitative MRI markers of brain waste clearance demonstrated region-dependent sensitivity in glymphatic impairment. The improved sensitivity of MRI markers in the olfactory bulb and the whole brain at an early DM stage may be attributed to the important role of the olfactory bulb in the parenchymal efflux pathway. MRI can provide sensitive quantitative markers of glymphatic impairment during the progression of DM and can be used as a valuable tool for the early diagnosis of DM with a potential for clinical application.
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Affiliation(s)
- Edward D. Boyd
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
| | - Lian Li
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
| | - Mei Lu
- Department of Public Health Sciences, Henry Ford Health System, Detroit, MI 48202, USA;
| | - Qingjiang Li
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
| | - Rui Huang
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
| | - Jasleen Kaur
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
| | - Jiani Hu
- Department of Radiology, Wayne State University, Detroit, MI 48202, USA;
| | - Michael Chopp
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
- Department of Physics, Oakland University, Rochester, MI 48309, USA
- Department of Neurology, Wayne State University, Detroit, MI 28202, USA
| | - Zhenggang Zhang
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
- Department of Neurology, Wayne State University, Detroit, MI 28202, USA
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, E&R B126, 2799 West Grand Boulevard, Detroit, MI 48202, USA; (L.Z.); (G.D.); (L.L.); (Q.L.); (J.K.); (M.C.); (Z.Z.); (Q.J.)
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA
- Department of Physics, Oakland University, Rochester, MI 48309, USA
- Department of Neurology, Wayne State University, Detroit, MI 28202, USA
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11
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Zhang J, Liu S, Wu Y, Tang Z, Wu Y, Qi Y, Dong F, Wang Y. Enlarged Perivascular Space and Index for Diffusivity Along the Perivascular Space as Emerging Neuroimaging Biomarkers of Neurological Diseases. Cell Mol Neurobiol 2023; 44:14. [PMID: 38158515 DOI: 10.1007/s10571-023-01440-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 11/12/2023] [Indexed: 01/03/2024]
Abstract
The existence of lymphatic vessels or similar clearance systems in the central nervous system (CNS) that transport nutrients and remove cellular waste is a neuroscientific question of great significance. As the brain is the most metabolically active organ in the body, there is likely to be a potential correlation between its clearance system and the pathological state of the CNS. Until recently the successive discoveries of the glymphatic system and the meningeal lymphatics solved this puzzle. This article reviews the basic anatomy and physiology of the glymphatic system. Imaging techniques to visualize the function of the glymphatic system mainly including post-contrast imaging techniques, indirect lymphatic assessment by detecting increased perivascular space, and diffusion tensor image analysis along the perivascular space (DTI-ALPS) are discussed. The pathological link between glymphatic system dysfunction and neurological disorders is the key point, focusing on the enlarged perivascular space (EPVS) and the index of diffusivity along the perivascular space (ALPS index), which may represent the activity of the glymphatic system as possible clinical neuroimaging biomarkers of neurological disorders. The pathological link between glymphatic system dysfunction and neurological disorders is the key point, focusing on the enlarged perivascular space (EPVS) and the index for of diffusivity along the perivascular space (ALPS index), which may represent the activity of the glymphatic system as possible clinical neuroimaging biomarkers of neurological disorders.
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Affiliation(s)
- Jun Zhang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Shengwen Liu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yaqi Wu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Zhijian Tang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yasong Wu
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yiwei Qi
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Fangyong Dong
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China
| | - Yu Wang
- Department of Neurosurgery, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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12
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Kaur J, Boyd E, Ding G, Zhang L, Luo H, Li Q, Li L, Wei M, Landschoot-Ward J, Chopp M, Zhang Z, Jiang Q. The Association between Glymphatic System and Perivascular Macrophages in Brain Waste Clearance. RESEARCH SQUARE 2023:rs.3.rs-3390074. [PMID: 37886481 PMCID: PMC10602168 DOI: 10.21203/rs.3.rs-3390074/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/28/2023]
Abstract
The glymphatic system suggests the convective bulk flow of cerebrospinal fluid (CSF) through perivascular spaces and the interstitial spaces of the brain parenchyma for the rapid removal of toxic waste solutes from the brain. However, the presence of convective bulk flow within the brain interstitial spaces is still under debate. We first addressed this argument to determine the involvement of the glymphatic system in brain waste clearance utilizing contrast-enhanced 3D T1-weighted imaging (T1WI), diffusion tensor imaging (DTI), and confocal microscopy imaging. Furthermore, perivascular macrophages (PVMs), which are immune cells located within perivascular spaces, have not been thoroughly explored for their association with the glymphatic system. Therefore, we investigated tracer uptake by PVMs in the perivascular spaces of both the arteries/arterioles and veins/venules and the potential association of PVMs in assisting the glymphatic system for interstitial waste clearance. Our findings demonstrated that both convective bulk flow and diffusion are responsible for the clearance of interstitial waste solutes from the brain parenchyma. Furthermore, our results suggested that PVMs play an important function in glymphatic system-mediated interstitial waste clearance. The glymphatic system and PVMs could be targeted to enhance interstitial waste clearance in patients with waste-associated neurological conditions and aging.
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Affiliation(s)
- Jasleen Kaur
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physics, Oakland University, Rochester, MI, USA
| | - Edward Boyd
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Radiology, Michigan State University, Lasing, MI, USA
| | - Guangliang Ding
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Radiology, Michigan State University, Lasing, MI, USA
| | - Li Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physiology, Michigan State University, Lasing, MI, USA
| | - Hao Luo
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | - Qingjiang Li
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | - Lian Li
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | - Min Wei
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
| | | | - Michael Chopp
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physics, Oakland University, Rochester, MI, USA
- Department of Physiology, Michigan State University, Lasing, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
| | - Zhenggang Zhang
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physiology, Michigan State University, Lasing, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
| | - Quan Jiang
- Department of Neurology, Henry Ford Health System, Detroit, MI, USA
- Department of Physics, Oakland University, Rochester, MI, USA
- Department of Radiology, Michigan State University, Lasing, MI, USA
- Department of Neurology, Wayne State University, Detroit, MI, USA
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13
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Dredla BK, Del Brutto OH, Castillo PR. Sleep and Perivascular Spaces. Curr Neurol Neurosci Rep 2023; 23:607-615. [PMID: 37572227 DOI: 10.1007/s11910-023-01293-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/31/2023] [Indexed: 08/14/2023]
Abstract
PURPOSE OF REVIEW The glymphatic system is hypothesized to act as the brain's filtration system to remove toxic solutes that accumulate throughout the day. Perivascular spaces (PVSs) play a fundamental role in the ability of the glymphatic system to function, and sleep influences the effectiveness of this system. This article reviews the complexity of the interplay between sleep, the glymphatic system, and PVS. RECENT FINDINGS New imaging techniques have illuminated the structure of PVS and their associations with differing disease states. Research has shown that sleep may play a key role in the function of PVS and the influence of adenosine, astrocyte, and aquaporin-4 channel in the function of the glymphatic system. Emerging data suggest that differing pathological states such as neuroinflammatory conditions, neurodegenerative diseases, and cognitive dysfunction may be associated with underlying glymphatic system dysfunction, and sleep disorders could be a potential intervention target.
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Affiliation(s)
- Brynn K Dredla
- Sleep Disorders Center, Mayo Clinic College of Medicine, Jacksonville, FL, USA
| | - Oscar H Del Brutto
- School of Medicine and Research Center, Universidad Espíritu Santo-Ecuador, Samborondón, Ecuador.
| | - Pablo R Castillo
- Sleep Disorders Center, Mayo Clinic College of Medicine, Jacksonville, FL, USA
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14
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Gędek A, Koziorowski D, Szlufik S. Assessment of factors influencing glymphatic activity and implications for clinical medicine. Front Neurol 2023; 14:1232304. [PMID: 37767530 PMCID: PMC10520725 DOI: 10.3389/fneur.2023.1232304] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Accepted: 08/22/2023] [Indexed: 09/29/2023] Open
Abstract
The glymphatic system is a highly specialized fluid transport system in the central nervous system. It enables the exchange of the intercellular fluid of the brain, regulation of the movement of this fluid, clearance of unnecessary metabolic products, and, potentially, brain immunity. In this review, based on the latest scientific reports, we present the mechanism of action and function of the glymphatic system and look at the role of factors influencing its activity. Sleep habits, eating patterns, coexisting stress or hypertension, and physical activity can significantly affect glymphatic activity. Modifying them can help to change lives for the better. In the next section of the review, we discuss the connection between the glymphatic system and neurological disorders. Its association with many disease entities suggests that it plays a major role in the physiology of the whole brain, linking many pathophysiological pathways of individual diseases.
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Affiliation(s)
- Adam Gędek
- Department of Neurology, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Poland
- Praski Hospital, Warsaw, Poland
| | - Dariusz Koziorowski
- Department of Neurology, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Poland
| | - Stanisław Szlufik
- Department of Neurology, Faculty of Health Sciences, Medical University of Warsaw, Warsaw, Poland
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15
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Smets NG, Strijkers GJ, Vinje V, Bakker ENTP. Cerebrospinal fluid turnover as a driver of brain clearance. NMR IN BIOMEDICINE 2023: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] [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.
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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
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16
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Zhu Y, Wang G, Kolluru C, Gu Y, Gao H, Zhang J, Wang Y, Wilson DL, Zhu X, Flask CA, Yu X. Transport pathways and kinetics of cerebrospinal fluid tracers in mouse brain observed by dynamic contrast-enhanced MRI. Sci Rep 2023; 13:13882. [PMID: 37620371 PMCID: PMC10449788 DOI: 10.1038/s41598-023-40896-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 08/17/2023] [Indexed: 08/26/2023] Open
Abstract
Recent studies have suggested the glymphatic system as a key mechanism of waste removal in the brain. Dynamic contrast-enhanced MRI (DCE-MRI) using intracisternally administered contrast agents is a promising tool for assessing glymphatic function in the whole brain. In this study, we evaluated the transport kinetics and distribution of three MRI contrast agents with vastly different molecular sizes in mice. Our results demonstrate that oxygen-17 enriched water (H217O), which has direct access to parenchymal tissues via aquaporin-4 water channels, exhibited significantly faster and more extensive transport compared to the two gadolinium-based contrast agents (Gd-DTPA and GadoSpin). Time-lagged correlation and clustering analyses also revealed different transport pathways for Gd-DTPA and H217O. Furthermore, there were significant differences in transport kinetics of the three contrast agents to the lateral ventricles, reflecting the differences in forces that drive solute transport in the brain. These findings suggest the size-dependent transport pathways and kinetics of intracisternally administered contrast agents and the potential of DCE-MRI for assessing multiple aspects of solute transport in the glymphatic system.
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Affiliation(s)
- Yuran Zhu
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Guanhua Wang
- Department of Biomedical Engineering, University of Michigan, Ann Arbor, MI, USA
| | - Chaitanya Kolluru
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Yuning Gu
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Huiyun Gao
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, USA
- Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - Jing Zhang
- Department of Biostatistics, Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Yunmei Wang
- Cardiovascular Research Institute, Case Western Reserve University, Cleveland, OH, USA
- Department of Medicine, Case Western Reserve University, Cleveland, OH, USA
| | - David L Wilson
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
- Department of Radiology, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
| | - Xiaofeng Zhu
- Department of Biostatistics, Population and Quantitative Health Sciences, Case Western Reserve University, Cleveland, OH, USA
| | - Chris A Flask
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
- Department of Radiology, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA
- Department of Pediatrics, Case Western Reserve University, Cleveland, OH, USA
| | - Xin Yu
- Department of Biomedical Engineering, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
- Department of Radiology, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
- Department of Physiology and Biophysics, Case Western Reserve University, Wickenden 430, 10900 Euclid Avenue, Cleveland, OH, 44106, USA.
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17
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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.
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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.
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18
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Wang Z, Song Z, Zhou C, Fang Y, Gu L, Yang W, Gao T, Si X, Liu Y, Chen Y, Guan X, Guo T, Wu J, Bai X, Zhang M, Zhang B, Pu J. Reduced coupling of global brain function and cerebrospinal fluid dynamics in Parkinson's disease. J Cereb Blood Flow Metab 2023; 43:1328-1339. [PMID: 36927139 PMCID: PMC10369155 DOI: 10.1177/0271678x231164337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/13/2022] [Revised: 01/18/2023] [Accepted: 01/23/2023] [Indexed: 03/18/2023]
Abstract
Dysfunction of the glymphatic system, an intracranial clearance pathway that drains misfolded proteins, has been implicated in the onset of Parkinson's disease (PD). Recently, the coupling strength of global blood-oxygen-level-dependent (gBOLD) signals and cerebrospinal fluid (CSF) inflow dynamics have been suggested to be an indicator of glymphatic function. Using resting-state functional magnetic resonance imaging (MRI), we quantified gBOLD-CSF coupling strength as the cross-correlation between baseline gBOLD and CSF inflow signals to evaluate glymphatic function and its association with the clinical manifestations of PD. We found that gBOLD-CSF coupling in drug-naïve PD patients was significantly weaker than that in normal controls, but significantly stronger in patients less affected by sleep disturbances than in those more affected by sleep disturbances, based on the PD sleep scale. Furthermore, we collected longitudinal data from patients and found that baseline gBOLD-CSF coupling negatively correlated with the rate of change over time, but positively correlated with the rate of change in UPDRS-III scores. In conclusion, severe gBOLD-CSF decoupling in PD patients may reflect longitudinal motor impairment, thereby providing a potential marker of glymphatic dysfunction in PD.
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Affiliation(s)
- Zhiyun Wang
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Zhe Song
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Cheng Zhou
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Yi Fang
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Luyan Gu
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Wenyi Yang
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Ting Gao
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Xiaoli Si
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Yi Liu
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Ying Chen
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Xiaojun Guan
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Tao Guo
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Jingjing Wu
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Xueqing Bai
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Minming Zhang
- Department of Radiology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Baorong Zhang
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
| | - Jiali Pu
- Department of Neurology, Second Affiliated Hospital, School of Medicine, Zhejiang University, China
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19
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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: 6] [Impact Index Per Article: 6.0] [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.
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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
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20
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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.
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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
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21
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Ozturk B, Koundal S, Al Bizri E, Chen X, Gursky Z, Dai F, Lim A, Heerdt P, Kipnis J, Tannenbaum A, Lee H, Benveniste H. Continuous positive airway pressure increases CSF flow and glymphatic transport. JCI Insight 2023; 8:e170270. [PMID: 37159262 PMCID: PMC10371231 DOI: 10.1172/jci.insight.170270] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Accepted: 05/04/2023] [Indexed: 05/10/2023] Open
Abstract
Respiration can positively influence cerebrospinal fluid (CSF) flow in the brain, yet its effects on central nervous system (CNS) fluid homeostasis, including waste clearance function via glymphatic and meningeal lymphatic systems, remain unclear. Here, we investigated the effect of supporting respiratory function via continuous positive airway pressure (CPAP) on glymphatic-lymphatic function in spontaneously breathing anesthetized rodents. To do this, we used a systems approach combining engineering, MRI, computational fluid dynamics analysis, and physiological testing. We first designed a nasal CPAP device for use in the rat and demonstrated that it functioned similarly to clinical devices, as evidenced by its ability to open the upper airway, augment end-expiratory lung volume, and improve arterial oxygenation. We further showed that CPAP increased CSF flow speed at the skull base and augmented glymphatic transport regionally. The CPAP-induced augmented CSF flow speed was associated with an increase in intracranial pressure (ICP), including the ICP waveform pulse amplitude. We suggest that the augmented pulse amplitude with CPAP underlies the increase in CSF bulk flow and glymphatic transport. Our results provide insights into the functional crosstalk at the pulmonary-CSF interface and suggest that CPAP might have therapeutic benefit for sustaining glymphatic-lymphatic function.
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Affiliation(s)
- Burhan Ozturk
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Sunil Koundal
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Ehab Al Bizri
- Department of Anesthesiology, Renaissance School of Medicine, Stony Brook University, Stony Brook, New York, USA
| | - Xinan Chen
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York City, New York, USA
| | - Zachary Gursky
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Feng Dai
- Quantitative Data Sciences, Global Product Development Pfizer Inc., Groton, Connecticut, USA
| | - Andrew Lim
- Department of Medicine, University of Toronto, Toronto, Canada
| | - Paul Heerdt
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Jonathan Kipnis
- Brain Immunology and Glia (BIG) Center, Department of Pathology and Immunology, Washington University School of Medicine, St. Louis, Missouri, USA
| | - Allen Tannenbaum
- Departments of Computer Science and Applied Mathematics & Statistics, College of Engineering and Applied Sciences, Stony Brook University, Stony Brook, New York, USA
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut, USA
- Department of Biomedical Engineering, Yale School of Medicine, New Haven, Connecticut, USA
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22
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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.
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23
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Segeroth M, Wachsmuth L, Gagel M, Albers F, Hess A, Faber C. Disentangling the impact of cerebrospinal fluid formation and neuronal activity on solute clearance from the brain. Fluids Barriers CNS 2023; 20:43. [PMID: 37316849 DOI: 10.1186/s12987-023-00443-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 05/18/2023] [Indexed: 06/16/2023] Open
Abstract
BACKGROUND Despite recent attention, pathways and mechanisms of fluid transposition in the brain are still a matter of intense discussion and driving forces underlying waste clearance in the brain remain elusive. Consensus exists that net solute transport is a prerequisite for efficient clearance. The individual impact of neuronal activity and cerebrospinal fluid (CSF) formation, which both vary with brain state and anesthesia, remain unclear. METHODS To separate conditions with high and low neuronal activity and high and low CSF formation, different anesthetic regimens in naive rat were established, using Isoflurane (ISO), Medetomidine (MED), acetazolamide or combinations thereof. With dynamic contrast-enhanced MRI, after application of low molecular weight contrast agent (CA) Gadobutrol to cisterna magna, tracer distribution was monitored as surrogate for solute clearance. Simultaneous fiber-based Ca2+-recordings informed about the state of neuronal activity under different anesthetic regimen. T2-weighted MRI and diffusion-weighted MRI (DWI) provided size of subarachnoidal space and aqueductal flow as surrogates for CSF formation. Finally, a pathway and mechanism-independent two-compartment model was introduced to provide a measure of efficiency for solute clearance from the brain. RESULTS Anatomical imaging, DWI and Ca2+-recordings confirmed that conditions with distinct levels of neuronal activity and CSF formation were achieved. A sleep-resembling condition, with reduced neuronal activity and enhanced CSF formation was achieved using ISO+MED and an awake-like condition with high neuronal activity using MED alone. CA distribution in the brain correlated with the rate of CSF formation. The cortical brain state had major influence on tracer diffusion. Under conditions with low neuronal activity, higher diffusivity suggested enlargement of extracellular space, facilitating a deeper permeation of solutes into brain parenchyma. Under conditions with high neuronal activity, diffusion of solutes into parenchyma was hindered and clearance along paravascular pathways facilitated. Exclusively based on the measured time signal curves, the two-compartment model provided net exchange ratios, which were significantly larger for the sleep-resembling condition than for the awake-like condition. CONCLUSIONS Efficiency of solute clearance in brain changes with alterations in both state of neuronal activity and CSF formation. Our clearance pathway and mechanism agnostic kinetic model informs about net solute transport, solely based on the measured time signal curves. This rather simplifying approach largely accords with preclinical and clinical findings.
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Affiliation(s)
- Martin Segeroth
- Translational Research Imaging Center (TRIC), Clinic of Radiology, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A16, 48149, Münster, Germany
- Department of Radiology, University Hospital Basel, Basel, Switzerland
| | - Lydia Wachsmuth
- Translational Research Imaging Center (TRIC), Clinic of Radiology, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A16, 48149, Münster, Germany
| | - Mathias Gagel
- Translational Research Imaging Center (TRIC), Clinic of Radiology, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A16, 48149, Münster, Germany
| | - Franziska Albers
- Translational Research Imaging Center (TRIC), Clinic of Radiology, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A16, 48149, Münster, Germany
| | - Andreas Hess
- Department of Experimental and Clinical Pharmacology and Toxicology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
- Institute of Neuroradiology, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg (FAU), Erlangen, Germany
- FAU NeW, Research Center for New Bioactive Compounds, Nikolaus-Fiebiger-Str. 10, 91058, Erlangen, Germany
| | - Cornelius Faber
- Translational Research Imaging Center (TRIC), Clinic of Radiology, University of Münster, Albert-Schweitzer-Campus 1, Gebäude A16, 48149, Münster, Germany.
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24
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Siddiqi AZ, Froese L, Gomez A, Sainbhi AS, Stein K, Park K, Vakitbilir N, Zeiler FA. The effect of burst suppression on cerebral blood flow and autoregulation: a scoping review of the human and animal literature. Front Physiol 2023; 14:1204874. [PMID: 37351255 PMCID: PMC10282505 DOI: 10.3389/fphys.2023.1204874] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 05/25/2023] [Indexed: 06/24/2023] Open
Abstract
Background: Burst suppression (BS) is an electroencephalography (EEG) pattern in which there are isoelectric periods interspersed with bursts of cortical activity. Targeting BS through anaesthetic administration is used as a tool in the neuro-intensive care unit but its relationship with cerebral blood flow (CBF) and cerebral autoregulation (CA) is unclear. We performed a systematic scoping review investigating the effect of BS on CBF and CA in animals and humans. Methods: We searched MEDLINE, BIOSIS, EMBASE, SCOPUS and Cochrane library from inception to August 2022. The data that were collected included study population, methods to induce and measure BS, and the effect on CBF and CA. Results: Overall, there were 66 studies that were included in the final results, 41 of which examined animals, 24 of which examined humans, and 1 of which examined both. In almost all the studies, BS was induced using an anaesthetic. In most of the animal and human studies, BS was associated with a decrease in CBF and cerebral metabolism, even if the mean arterial pressure remained constant. The effect on CA during periods of stress (hypercapnia, hypothermia, etc.) was variable. Discussion: BS is associated with a reduction in cerebral metabolic demand and CBF, which may explain its usefulness in patients with brain injury. More evidence is needed to elucidate the connection between BS and CA.
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Affiliation(s)
- A. Zohaib Siddiqi
- Department of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Logan Froese
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Alwyn Gomez
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Amanjyot Singh Sainbhi
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Kevin Stein
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Kangyun Park
- Undergraduate Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
| | - Nuray Vakitbilir
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
| | - Frederick A. Zeiler
- Biomedical Engineering, Faculty of Engineering, University of Manitoba, Winnipeg, MB, Canada
- Department of Human Anatomy and Cell Science, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Section of Neurosurgery, Department of Surgery, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB, Canada
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
- Division of Anaesthesia, Department of Medicine, Addenbrooke’s Hospital, University of Cambridge, Cambridge, United Kingdom
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25
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Liu Y, Liu X, Sun P, Li J, Nie M, Gong J, He A, Zhao M, Yang C, Wang Z. rTMS treatment for abrogating intracerebral hemorrhage-induced brain parenchymal metabolite clearance dysfunction in male mice by regulating intracranial lymphatic drainage. Brain Behav 2023:e3062. [PMID: 37161559 DOI: 10.1002/brb3.3062] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 04/17/2023] [Indexed: 05/11/2023] Open
Abstract
BACKGROUND The discovery of the glymphatic system and meningeal lymphatic vessels challenged the traditional view regarding the lack of a lymphatic system in the central nervous system. It is now known that the intracranial lymphatic system plays an important role in fluid transport, macromolecule uptake, and immune cell trafficking. Studies have also shown that the function of the intracranial lymphatic system is significantly associated with neurological diseases; for example, an impaired intracranial lymphatic system can lead to Tau deposition and an increased lymphocyte count in the brain tissue of mice with subarachnoid hemorrhage. METHODS In this study, we assessed the changes in the intracranial lymphatic system after intracerebral hemorrhage and the regulatory effects of repeated transcranial magnetic stimulation on the glymphatic system and meningeal lymphatic vessels in an intracerebral hemorrhage (ICH) model of male mice. Experimental mice were divided into three groups: Sham, ICH, and ICH + repeated transcranial magnetic stimulation (rTMS). Three days after ICH, mice in the ICH+rTMS group were subjected to rTMS daily for 7 days. Thereafter, the function of the intracranial lymphatic system, clearance of RITC-dextran and FITC-dextran, and neurological functions were evaluated. RESULTS Compared with the Sham group, the ICH group had an impaired glymphatic system. Importantly, rTMS treatment could improve intracranial lymphatic system function as well as behavioral functions and enhance the clearance of parenchymal RITC-dextran and FITC-dextran after ICH. CONCLUSION Our results indicate that rTMS can abrogate ICH-induced brain parenchymal metabolite clearance dysfunction by regulating intracranial lymphatic drainage.
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Affiliation(s)
- Yuheng Liu
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Xuanhui Liu
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Pengju Sun
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Department of Neurosurgery, Fuyang People's Hospital, Fuyang, China
| | - Jing Li
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Meng Nie
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Junjie Gong
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Anqi He
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Mingyu Zhao
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Chen Yang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
- Tianjin Neurological Institute, Key Laboratory of Post-Neuroinjury Neuro-Repair and Regeneration in Central Nervous System, Ministry of Education and Tianjin, Tianjin, China
| | - Zengguang Wang
- Department of Neurosurgery, Tianjin Medical University General Hospital, Tianjin, China
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26
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Wang X, Leong ATL, Tan SZK, Wong EC, Liu Y, Lim LW, Wu EX. Functional MRI reveals brain-wide actions of thalamically-initiated oscillatory activities on associative memory consolidation. Nat Commun 2023; 14:2195. [PMID: 37069169 PMCID: PMC10110623 DOI: 10.1038/s41467-023-37682-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 03/27/2023] [Indexed: 04/19/2023] Open
Abstract
As a key oscillatory activity in the brain, thalamic spindle activities are long believed to support memory consolidation. However, their propagation characteristics and causal actions at systems level remain unclear. Using functional MRI (fMRI) and electrophysiology recordings in male rats, we found that optogenetically-evoked somatosensory thalamic spindle-like activities targeted numerous sensorimotor (cortex, thalamus, brainstem and basal ganglia) and non-sensorimotor limbic regions (cortex, amygdala, and hippocampus) in a stimulation frequency- and length-dependent manner. Thalamic stimulation at slow spindle frequency (8 Hz) and long spindle length (3 s) evoked the most robust brain-wide cross-modal activities. Behaviorally, evoking these global cross-modal activities during memory consolidation improved visual-somatosensory associative memory performance. More importantly, parallel visual fMRI experiments uncovered response potentiation in brain-wide sensorimotor and limbic integrative regions, especially superior colliculus, periaqueductal gray, and insular, retrosplenial and frontal cortices. Our study directly reveals that thalamic spindle activities propagate in a spatiotemporally specific manner and that they consolidate associative memory by strengthening multi-target memory representation.
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Affiliation(s)
- Xunda Wang
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Alex T L Leong
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Shawn Z K Tan
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Eddie C Wong
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Yilong Liu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Lee-Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Ed X Wu
- Laboratory of Biomedical Imaging and Signal Processing, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
- Department of Electrical and Electronic Engineering, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China.
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27
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Sepehrinezhad A, Stolze Larsen F, Ashayeri Ahmadabad R, Shahbazi A, Sahab Negah S. The Glymphatic System May Play a Vital Role in the Pathogenesis of Hepatic Encephalopathy: A Narrative Review. Cells 2023; 12:cells12070979. [PMID: 37048052 PMCID: PMC10093707 DOI: 10.3390/cells12070979] [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: 10/19/2022] [Revised: 02/20/2023] [Accepted: 03/21/2023] [Indexed: 04/14/2023] Open
Abstract
Hepatic encephalopathy (HE) is a neurological complication of liver disease resulting in cognitive, psychiatric, and motor symptoms. Although hyperammonemia is a key factor in the pathogenesis of HE, several other factors have recently been discovered. Among these, the impairment of a highly organized perivascular network known as the glymphatic pathway seems to be involved in the progression of some neurological complications due to the accumulation of misfolded proteins and waste substances in the brain interstitial fluids (ISF). The glymphatic system plays an important role in the clearance of brain metabolic derivatives and prevents aggregation of neurotoxic agents in the brain ISF. Impairment of it will result in aggravated accumulation of neurotoxic agents in the brain ISF. This could also be the case in patients with liver failure complicated by HE. Indeed, accumulation of some metabolic by-products and agents such as ammonia, glutamine, glutamate, and aromatic amino acids has been reported in the human brain ISF using microdialysis technique is attributed to worsening of HE and correlates with brain edema. Furthermore, it has been reported that the glymphatic system is impaired in the olfactory bulb, prefrontal cortex, and hippocampus in an experimental model of HE. In this review, we discuss different factors that may affect the function of the glymphatic pathways and how these changes may be involved in HE.
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Affiliation(s)
- Ali Sepehrinezhad
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran 1449614535, Iran
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad 9919191778, Iran
| | - Fin Stolze Larsen
- Department of Gastroenterology and Hepatology, Rigshospitalet, Copenhagen University Hospital, 999017 Copenhagen, Denmark
| | | | - Ali Shahbazi
- Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran 1449614535, Iran
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran 1449614535, Iran
| | - Sajad Sahab Negah
- Neuroscience Research Center, Mashhad University of Medical Sciences, Mashhad 9919191778, Iran
- Shefa Neuroscience Research Center, Khatam Alanbia Hospital, Tehran 1449614535, Iran
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28
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Min J, Rouanet J, Martini AC, Nashiro K, Yoo HJ, Porat S, Cho C, Wan J, Cole SW, Head E, Nation DA, Thayer JF, Mather M. Modulating heart rate oscillation affects plasma amyloid beta and tau levels in younger and older adults. Sci Rep 2023; 13:3967. [PMID: 36894565 PMCID: PMC9998394 DOI: 10.1038/s41598-023-30167-0] [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] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 02/16/2023] [Indexed: 03/11/2023] Open
Abstract
Slow paced breathing via heart rate variability (HRV) biofeedback stimulates vagus-nerve pathways that counter noradrenergic stress and arousal pathways that can influence production and clearance of Alzheimer's disease (AD)-related proteins. Thus, we examined whether HRV biofeedback intervention affects plasma Αβ40, Αβ42, total tau (tTau), and phosphorylated tau-181 (pTau-181) levels. We randomized healthy adults (N = 108) to use slow-paced breathing with HRV biofeedback to increase heart rate oscillations (Osc+) or to use personalized strategies with HRV biofeedback to decrease heart rate oscillations (Osc-). They practiced 20-40 min daily. Four weeks of practicing the Osc+ and Osc- conditions produced large effect size differences in change in plasma Aβ40 and Aβ42 levels. The Osc+ condition decreased plasma Αβ while the Osc- condition increased Αβ. Decreases in Αβ were associated with decreases in gene transcription indicators of β-adrenergic signaling, linking effects to the noradrenergic system. There were also opposing effects of the Osc+ and Osc- interventions on tTau for younger adults and pTau-181 for older adults. These results provide novel data supporting a causal role of autonomic activity in modulating plasma AD-related biomarkers.Trial registration: NCT03458910 (ClinicalTrials.gov); first posted on 03/08/2018.
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Affiliation(s)
- Jungwon Min
- University of Southern California, Los Angeles, CA, USA
| | | | | | - Kaoru Nashiro
- University of Southern California, Los Angeles, CA, USA
| | - Hyun Joo Yoo
- University of Southern California, Los Angeles, CA, USA
| | - Shai Porat
- University of Southern California, Los Angeles, CA, USA
| | - Christine Cho
- University of Southern California, Los Angeles, CA, USA
| | - Junxiang Wan
- University of Southern California, Los Angeles, CA, USA
| | - Steve W Cole
- University of California, Los Angeles, Los Angeles, CA, USA
| | | | | | | | - Mara Mather
- University of Southern California, Los Angeles, CA, USA.
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29
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Georgakopoulou T, van der Wijk AE, van Bavel E, Bakker ENTP. Perivascular clearance of blood proteins after blood-brain barrier disruption in a rat model of microinfarcts. Microvasc Res 2023; 148:104515. [PMID: 36893583 DOI: 10.1016/j.mvr.2023.104515] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2022] [Revised: 02/15/2023] [Accepted: 03/01/2023] [Indexed: 03/09/2023]
Abstract
Microinfarcts result in a transient loss of the blood-brain barrier (BBB) in the ischemic territory. This leads to the extravasation of blood proteins into the brain parenchyma. It is not clear how these proteins are removed. Here we studied the role of perivascular spaces in brain clearance from extravasated blood proteins. Male and female Wistar rats were infused with microspheres of either 15, 25, or 50 μm in diameter (n = 6 rats per group) via the left carotid artery. We infused either 25,000 microspheres of 15 μm, 5500 of 25 μm, or 1000 of 50 μm. One day later, rats were infused with lectin and hypoxyprobe to label perfused blood vessels and hypoxic areas, respectively. Rats were then euthanized and perfusion-fixed. Brains were excised, sectioned, and analyzed using immunostaining and confocal imaging. Microspheres induced a size-dependent increase in ischemic volume per territory, but the cumulative ischemic volume was similar in all groups. The total volumes of ischemia, hypoxia and infarction affected 1-2 % of the left hemisphere. Immunoglobulins (IgG) were present in ischemic brain tissue surrounding lodged microspheres in all groups. In addition, staining for IgG was found in perivascular spaces of blood vessels nearby areas of BBB disruption. About 2/3 of these vessels were arteries, while the remaining 1/3 of these vessels were veins. The subarachnoid space (SAS) of the affected hemisphere stained stronger for IgG than the contralateral hemisphere in all groups: +27 %, +44 % and +27 % respectively. Microspheres of various sizes induce a local loss of BBB integrity, evidenced by parenchymal IgG staining. The presence of IgG in perivascular spaces of both arteries and veins distinct from the ischemic territories suggests that both contribute to the removal of blood proteins. The strong staining for IgG in the SAS of the affected hemisphere suggests that this perivascular route egresses via the CSF. Perivascular spaces therefore play a previously unrecognized role in tissue clearance of fluid and extravasated proteins after BBB disruption induced by microinfarcts.
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Affiliation(s)
- Theodosia Georgakopoulou
- Amsterdam UMC Location University of Amsterdam, Biomedical Engineering and Physics, Meibergdreef 9, Amsterdam, the Netherlands
| | - Anne-Eva van der Wijk
- Amsterdam UMC Location University of Amsterdam, Biomedical Engineering and Physics, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, the Netherlands
| | - Ed van Bavel
- Amsterdam UMC Location University of Amsterdam, Biomedical Engineering and Physics, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, the Netherlands; Amsterdam Neuroscience, Neurovascular Disorders, Amsterdam, the Netherlands
| | - Erik N T P Bakker
- Amsterdam UMC Location University of Amsterdam, Biomedical Engineering and Physics, Meibergdreef 9, Amsterdam, the Netherlands; Amsterdam Cardiovascular Sciences, Microcirculation, Amsterdam, the Netherlands; Amsterdam Neuroscience, Neurovascular Disorders, Amsterdam, the Netherlands.
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30
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Lilius TO, Mortensen KN, Deville C, Lohela TJ, Stæger FF, Sigurdsson B, Fiordaliso EM, Rosenholm M, Kamphuis C, Beekman FJ, Jensen AI, Nedergaard M. Glymphatic-assisted perivascular brain delivery of intrathecal small gold nanoparticles. J Control Release 2023; 355:135-148. [PMID: 36731802 DOI: 10.1016/j.jconrel.2023.01.054] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2022] [Revised: 11/05/2022] [Accepted: 01/18/2023] [Indexed: 02/04/2023]
Abstract
Nanoparticles are ultrafine particulate matter having considerable potential for treatment of central nervous system (CNS) disorders. Despite their tiny size, the blood-brain barrier (BBB) restricts their access to the CNS. Their direct cerebrospinal fluid (CSF) administration bypasses the BBB endothelium, but still fails to give adequate brain uptake. We present a novel approach for efficient CNS delivery of 111In-radiolabelled gold nanoparticles (AuNPs; 10-15 nm) via intra-cisterna magna administration, with tracking by SPECT imaging. To accelerate CSF brain influx, we administered AuNPs intracisternally in conjunction with systemic hypertonic saline, which dramatically increased the parenchymal AuNP uptake, especially in deep brain regions. AuNPs entered the CNS along periarterial spaces as visualized by MRI of gadolinium-labelled AuNPs and were cleared from brain within 24 h and excreted through the kidneys. Thus, the glymphatic-assisted perivascular network augment by systemic hypertonic saline is a pathway for highly efficient brain-wide distribution of small AuNPs.
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Affiliation(s)
- Tuomas O Lilius
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Department of Pharmacology, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Department of Emergency Medicine and Services, University of Helsinki and Helsinki University Hospital, Finland
| | - Kristian Nygaard Mortensen
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Claire Deville
- The Hevesy Laboratory, Department of Health Technology, Technical University of Denmark, Roskilde, Denmark
| | - Terhi J Lohela
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland; Department of Anaesthesiology, Intensive Care Medicine, and Pain Medicine, University of Helsinki and Helsinki University Hospital, Finland
| | - Frederik Filip Stæger
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Björn Sigurdsson
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Elisabetta M Fiordaliso
- DTU Nanolab - National Center for Nano Fabrication and Characterization, Technical University of Denmark, Kgs. Lyngby, Denmark
| | - Marko Rosenholm
- Center for Translational Neuromedicine, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark; Individualized Drug Therapy Research Program, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Chris Kamphuis
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands; MILabs B.V., Utrecht, the Netherlands
| | - Freek J Beekman
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, the Netherlands; MILabs B.V., Utrecht, the Netherlands; Department of Radiation Science and Technology, Delft University of Technology, Delft, the Netherlands
| | - Andreas I Jensen
- The Hevesy Laboratory, Department of Health Technology, Technical University of Denmark, Roskilde, Denmark.
| | - 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, NY, USA.
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Association of AQP4 single nucleotide polymorphisms (rs335929 and rs2075575) with Parkinson's disease: A case-control study. Neurosci Lett 2023; 797:137062. [PMID: 36626962 DOI: 10.1016/j.neulet.2023.137062] [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: 12/16/2022] [Revised: 01/06/2023] [Accepted: 01/06/2023] [Indexed: 01/09/2023]
Abstract
OBJECTIVE The glymphatic system plays an important role in brain waste removal and is functionally and structurally dependent on astrocyte aquaporin-4 (AQP4). Genetic variation in the AQP4 gene has therefore been hypothesized to be associated with genetic susceptibility to neurodegenerative diseases. This study aimed to investigate whether two specific single nucleotide polymorphisms (SNP) in the AQP4 gene, rs335929, and rs2075575, are associated with the risk and clinical features of PD. METHODS A total of 950 participants, including 475 patients with sporadic PD and 475 independent healthy controls, were included in this case-control study. Two SNPs (rs335929 and rs2075575) of the AQP4 gene were genotyped using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Sanger sequencing was used to determine whether the genotyping results were accurate. A chi-square (χ2) test was used to compare the frequencies of alleles and genotypes between patients and controls. Logistic regression was used to calculate dominance ratios (OR) and 95% confidence intervals (CI). RESULTS The difference between rs2075575 in the dominant model (GG vs GA + AA: P = 0.019) and the overdominant model (GG + AA vs GA: P = 0.013) was statistically significant. Subgroup analysis showed that the frequency of the rs2075575 A allele was significantly higher in female PD patients than in matched female controls (P = 0.017). rs2075575 A allele was significantly more frequent in LOPD patients than in matched elderly controls (P = 0.033). rs335929 polymorphism was not significantly correlated with PD susceptibility in either the overall or subgroup analysis. Haplotype analysis between the two SNPs did not show an association with PD susceptibility. In addition, we found that the rs2075575 G allele was significantly associated with Rapid Eye Movement Behaviour Disorder (RBD) (P = 0.044), and the rs335929 A allele with memory impairment (P = 0.028) in PD. CONCLUSION The AQP4 gene rs2075575 polymorphism may be associated with PD susceptibility, but not the rs335929 polymorphism. rs2075575 is associated with RBD and rs335929 is associated with memory cognition. Regulation of the glymphatic system by interfering with the genetics of AQP4 and thus influencing the pathology of PD may be a direction worth investigating. Studies in larger sample sizes and across ethnicities are essential for further understanding the potential association between AQP genes and PD pathogenesis.
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Zhu Y, Wang G, Kolluru C, Gu Y, Gao H, Zhang J, Wang Y, Wilson DL, Zhu X, Flask CA, Yu X. Transport Pathways and Kinetics of Cerebrospinal Fluid Tracers in Mouse Brain Observed by Dynamic Contrast-Enhanced MRI. RESEARCH SQUARE 2023:rs.3.rs-2544475. [PMID: 36798228 PMCID: PMC9934740 DOI: 10.21203/rs.3.rs-2544475/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 02/10/2023]
Abstract
Background: Recent studies have suggested the glymphatic system as a solute transport pathway and waste removal mechanism in the brain. Imaging intracisternally administered tracers provides the opportunity of assessing various aspects of the glymphatic function. Dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) allows the evaluation of both the kinetics and spatial distribution of tracer transport in the whole brain. However, assessing mouse glymphatic function by DCE-MRI has been challenged by the small size of a mouse brain and the limited volume of fluids that can be delivered intracisternally without significantly altering the intracranial pressure. Further, previous studies in rats suggest that assessment of glymphatic function by DCE-MRI is dependent on the molecular size of the contrast agents. Methods: We established and validated an intracisternal infusion protocol in mice that allowed the measurements of the entire time course of contrast agent transport for 2 hours. The transport kinetics and distribution of three MRI contrast agents with drastically different molecular weights (MWs): Gd-DTPA (MW=661.8 Da, n=7), GadoSpin-P (MW=200 kDa, n=6), and oxygen-17 enriched water (H 2 17 O, MW=19 Da, n=7), were investigated. Results: The transport of H 2 17 O was significantly faster and more extensive than the two gadolinium-based contrast agents. Time-lagged correlation analysis and clustering analysis comparing the kinetics of Gd-DTPA and H 2 17 O transport also showed different cluster patterns and lag time between different regions of the brain, suggesting different transport pathways for H 2 17 O because of its direct access to parenchymal tissues via the aquaporin-4 water channels. Further, there were also significant differences in the transport kinetics of the three tracers to the lateral ventricles, which reflects the differences in forces that drive tracer transport in the brain. Conclusions: Comparison of the transport kinetics and distribution of three MRI contrast agents with different molecular sizes showed drastically different transport profiles and clustering patterns, suggesting that the transport pathways and kinetics in the glymphatic system are size-dependent.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Xin Yu
- Case Western Reserve University
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Lan YL, Wang H, Chen A, Zhang J. Update on the current knowledge of lymphatic drainage system and its emerging roles in glioma management. Immunology 2023; 168:233-247. [PMID: 35719015 DOI: 10.1111/imm.13517] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/22/2022] [Indexed: 01/17/2023] Open
Abstract
The draining of brain interstitial fluid (ISF) to cerebrospinal fluid (CSF) and the subsequent draining of CSF to meningeal lymphatics is well-known. Nonetheless, its role in the development of glioma is a remarkable finding that has to be extensively understood. The glymphatic system (GS) collects CSF from the subarachnoid space and brain ISF through aquaporin-4 (AQP4) water channels. The glial limiting membrane and the perivascular astrocyte-end-feet membrane both have elevated levels of AQP4. CSF is thought to drain through the nerve sheaths of the olfactory and other cranial nerves as well as spinal meningeal lymphatics via dorsal or basal lymphatic vessels. Meningeal lymphatic vessels (MLVs) exist below the skull in the dorsal and basal regions. In this view, MLVs offer a pathway to drain macromolecules and traffic immunological cells from the CNS into cervical lymph nodes (CLNs), and thus can be used as a candidate curing strategy against glioma and other associated complications, such as neuro-inflammation. Taken together, the lymphatic drainage system could provide a route or approach for drug targeting of glioma and other neurological conditions. Nevertheless, its pathophysiological role in glioma remains elusive, which needs extensive research. The current review aims to explore the lymphatic drainage system, its role in glioma progression, and possible therapeutic techniques that target MLVs in the CNS.
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Affiliation(s)
- Yu-Long Lan
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Hongjin Wang
- Department of Neurology, Second Affiliated Hospital of Dalian Medical University, Dalian, Liaoning, China
| | - Aiqin Chen
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
| | - Jianmin Zhang
- Department of Neurosurgery, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang, China
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Qu JZ, Mueller A, McKay TB, Westover MB, Shelton KT, Shaefi S, D'Alessandro DA, Berra L, Brown EN, Houle TT, Akeju O. Nighttime dexmedetomidine for delirium prevention in non-mechanically ventilated patients after cardiac surgery (MINDDS): A single-centre, parallel-arm, randomised, placebo-controlled superiority trial. EClinicalMedicine 2023; 56:101796. [PMID: 36590787 PMCID: PMC9800196 DOI: 10.1016/j.eclinm.2022.101796] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2022] [Revised: 11/30/2022] [Accepted: 12/02/2022] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND The delirium-sparing effect of nighttime dexmedetomidine has not been studied after surgery. We hypothesised that a nighttime dose of dexmedetomidine would reduce the incidence of postoperative delirium as compared to placebo. METHODS This single-centre, parallel-arm, randomised, placebo-controlled superiority trial evaluated whether a short nighttime dose of intravenous dexmedetomidine (1 μg/kg over 40 min) would reduce the incidence of postoperative delirium in patients 60 years of age or older undergoing elective cardiac surgery with cardiopulmonary bypass. Patients were randomised to receive dexmedetomidine or placebo in a 1:1 ratio. The primary outcome was delirium on postoperative day one. Secondary outcomes included delirium within three days of surgery, 30-, 90-, and 180-day abbreviated Montreal Cognitive Assessment scores, Patient Reported Outcome Measures Information System quality of life scores, and all-cause mortality. The study was registered as NCT02856594 on ClinicalTrials.gov on August 5, 2016, before the enrolment of any participants. FINDINGS Of 469 patients that underwent randomisation to placebo (n = 235) or dexmedetomidine (n = 234), 75 met a prespecified drop criterion before the study intervention. Thus, 394 participants (188 dexmedetomidine; 206 placebo) were analysed in the modified intention-to-treat cohort (median age 69 [IQR 64, 74] years; 73.1% male [n = 288]; 26·9% female [n = 106]). Postoperative delirium status on day one was missing for 30 (7.6%) patients. Among those in whom it could be assessed, the primary outcome occurred in 5 of 175 patients (2.9%) in the dexmedetomidine group and 16 of 189 patients (8.5%) in the placebo group (OR 0.32, 95% CI: 0.10-0.83; P = 0.029). A non-significant but higher proportion of participants experienced delirium within three days postoperatively in the placebo group (25/177; 14.1%) compared to the dexmedetomidine group (14/160; 8.8%; OR 0.58; 95% CI, 0.28-1.15). No significant differences between groups were observed in secondary outcomes or safety. INTERPRETATION Our findings suggested that in elderly cardiac surgery patients with a low baseline risk of postoperative delirium and extubated within 12 h of ICU admission, a short nighttime dose of dexmedetomidine decreased the incidence of delirium on postoperative day one. Although non-statistically significant, our findings also suggested a clinical meaningful difference in the three-day incidence of postoperative delirium. FUNDING National Institute on Aging (R01AG053582).
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Affiliation(s)
- Jason Z. Qu
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Ariel Mueller
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Tina B. McKay
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - M. Brandon Westover
- Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Kenneth T. Shelton
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Shahzad Shaefi
- Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - David A. D'Alessandro
- Division of Cardiac Surgery, Department of Surgery, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Lorenzo Berra
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Respiratory Care Services, Massachusetts General Hospital, Boston, MA, USA
| | - Emery N. Brown
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Institute for Medical Engineering and Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Timothy T. Houle
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Oluwaseun Akeju
- Department of Anesthesia, Critical Care and Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Corresponding author. Massachusetts General Hospital, 55 Fruit Street, Gray Bigelow 444, Boston, MA 02114, USA.
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Could dexmedetomidine be repurposed as a glymphatic enhancer? Trends Pharmacol Sci 2022; 43:1030-1040. [PMID: 36280451 DOI: 10.1016/j.tips.2022.09.007] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 09/26/2022] [Accepted: 09/26/2022] [Indexed: 11/06/2022]
Abstract
Cerebrospinal fluid (CSF) flows through the central nervous system (CNS) via the glymphatic pathway to clear the interstitium of metabolic waste. In preclinical studies, glymphatic fluid flow rate increases with low central noradrenergic tone and slow-wave activity during natural sleep and general anesthesia. By contrast, sleep deprivation reduces glymphatic clearance and leads to intracerebral accumulation of metabolic waste, suggesting an underlying mechanism linking sleep disturbances with neurodegenerative diseases. The selective α2-adrenergic agonist dexmedetomidine is a sedative drug that induces slow waves in the electroencephalogram, suppresses central noradrenergic tone, and preserves glymphatic outflow. As recently developed dexmedetomidine formulations enable self-administration, we suggest that dexmedetomidine could serve as a sedative-hypnotic drug to enhance clearance of harmful waste from the brain of those vulnerable to neurodegeneration.
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Lee H, Ozturk B, Stringer MS, Koundal S, MacIntosh BJ, Rothman D, Benveniste H. Choroid plexus tissue perfusion and blood to CSF barrier function in rats measured with continuous arterial spin labeling. Neuroimage 2022; 261:119512. [PMID: 35882269 PMCID: PMC9969358 DOI: 10.1016/j.neuroimage.2022.119512] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2022] [Revised: 06/18/2022] [Accepted: 07/22/2022] [Indexed: 02/08/2023] Open
Abstract
The choroid plexus (ChP) of the cerebral ventricles is a source of cerebrospinal fluid (CSF) production and also plays a key role in immune surveillance at the level of blood-to-CSF-barrier (BCSFB). In this study, we quantify ChP blood perfusion and BCSFB mediated water exchange from arterial blood into ventricular CSF using non-invasive continuous arterial spin labelling magnetic resonance imaging (CASL-MRI). Systemic administration of anti-diuretic hormone (vasopressin) was used to validate BCSFB water flow as a metric of choroidal CSF secretory function. To further investigate the coupling between ChP blood perfusion and BCSFB water flow, we characterized the effects of two anesthetic regimens known to have large-scale differential effects on cerebral blood flow. For quantification of ChP blood perfusion a multi-compartment perfusion model was employed, and we discovered that partial volume correction improved measurement accuracy. Vasopressin significantly reduced both ChP blood perfusion and BCSFB water flow. ChP blood perfusion was significantly higher with pure isoflurane anesthesia (2-2.5%) when compared to a balanced anesthesia with dexmedetomidine and low-dose isoflurane (1.0 %), and significant correlation between ChP blood perfusion and BCSFB water flow was observed, however there was no significant difference in BCSFB water flow. In summary, here we introduce a non-invasive, robust, and spatially resolved in vivo imaging platform to quantify ChP blood perfusion as well as BCSFB water flow which can be applied to study coupling of these two key parameters in future clinical translational studies.
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Affiliation(s)
- Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA.
| | - Burhan Ozturk
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Michael S Stringer
- Brain Research Imaging Centre and UK Dementia Research Institute, Centre for Clinical Brain Sciences, University of Edinburgh, Edinburgh, UK
| | - Sunil Koundal
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Bradley J MacIntosh
- Department of Medical Biophysics, Faculty of Medicine, University of Toronto, Toronto, Canada
| | - Douglas Rothman
- Departments of Radiology and Biomedical Imaging, Yale School of Medicine, New Haven, CT, USA
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
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37
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Zhao L, Tannenbaum A, Bakker ENTP, Benveniste H. Physiology of Glymphatic Solute Transport and Waste Clearance from the Brain. Physiology (Bethesda) 2022; 37:0. [PMID: 35881783 PMCID: PMC9550574 DOI: 10.1152/physiol.00015.2022] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 07/12/2022] [Accepted: 07/20/2022] [Indexed: 12/25/2022] Open
Abstract
This review focuses on the physiology of glymphatic solute transport and waste clearance, using evidence from experimental animal models as well as from human studies. Specific topics addressed include the biophysical characteristics of fluid and solute transport in the central nervous system, glymphatic-lymphatic coupling, as well as the role of cerebrospinal fluid movement for brain waste clearance. We also discuss the current understanding of mechanisms underlying increased waste clearance during sleep.
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Affiliation(s)
- Lucy Zhao
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut
| | - Allen Tannenbaum
- Departments of Computer Science and Applied Mathematics and Statistics, Stony Brook University, Stony Brook, New York
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York City, New York
| | - Erik N T P Bakker
- Department of Biomedical Engineering and Physics, Amsterdam UMC, Amsterdam Cardiovascular Sciences, University of Amsterdam, Amsterdam, The Netherlands
| | - Helene Benveniste
- Department of Anesthesiology, Yale School of Medicine, New Haven, Connecticut
- Department of Biomedical Engineering, Yale School of Medicine, New Haven, Connecticut
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He XZ, Li X, Li ZH, Meng JC, Mao RT, Zhang XK, Zhang RT, Huang HL, Gui Q, Xu GY, Wang LH. High-resolution 3D demonstration of regional heterogeneity in the glymphatic system. J Cereb Blood Flow Metab 2022; 42:2017-2031. [PMID: 35786032 PMCID: PMC9580176 DOI: 10.1177/0271678x221109997] [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: 11/16/2022]
Abstract
Accumulating evidence indicates that the glymphatic system has a critical role in maintaining brain homeostasis. However, the detailed anatomy of the glymphatic pathway is not well understood, mostly due to a lack of high spatial resolution 3D visualization. In this study, a fluorescence micro-optical sectioning tomography (fMOST) was used to characterize the glymphatic architecture in the mouse brain. At 30 and 120 min after intracisternal infusion with fluorescent dextran (Dex-3), lectin was injected to stain the cerebral vasculature. Using fMOST, a high-resolution 3D dataset of the brain-wide distribution of Dex-3 was acquired. Combined with fluorescence microscopy and microplate array, the heterogeneous glymphatic flow and the preferential irrigated regions were identified. These cerebral regions containing large-caliber penetrating arteries and/or adjacent to the subarachnoid space had more robust CSF flow compared to other regions. Moreover, the major glymphatic vessels for CSF influx and fluid efflux in the entire brain were shown in 3D. This study demonstrates the regional heterogeneity in the glymphatic system and provides an anatomical resource for further investigation of the glymphatic function.
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Affiliation(s)
- Xu-Zhong He
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Xin Li
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Zhen-Hua Li
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Jing-Cai Meng
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Rui-Ting Mao
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Xue-Ke Zhang
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Rong-Ting Zhang
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Huai-Liang Huang
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
| | - Qian Gui
- Department of Neurology, Suzhou Municipal Hospital, Suzhou, PR China
| | - Guang-Yin Xu
- Institute of Neuroscience, Soochow University, Suzhou, PR China
| | - Lin-Hui Wang
- Department of Physiology and Neurobiology, Suzhou Medical College of Soochow University, Suzhou, PR China
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Tu W, Zhang N. Neural underpinning of a respiration-associated resting-state fMRI network. eLife 2022; 11:e81555. [PMID: 36263940 PMCID: PMC9645809 DOI: 10.7554/elife.81555] [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: 07/01/2022] [Accepted: 10/13/2022] [Indexed: 11/13/2022] Open
Abstract
Respiration can induce motion and CO2 fluctuation during resting-state fMRI (rsfMRI) scans, which will lead to non-neural artifacts in the rsfMRI signal. In the meantime, as a crucial physiologic process, respiration can directly drive neural activity change in the brain, and may thereby modulate the rsfMRI signal. Nonetheless, this potential neural component in the respiration-fMRI relationship is largely unexplored. To elucidate this issue, here we simultaneously recorded the electrophysiology, rsfMRI, and respiration signals in rats. Our data show that respiration is indeed associated with neural activity changes, evidenced by a phase-locking relationship between slow respiration variations and the gamma-band power of the electrophysiological signal recorded in the anterior cingulate cortex. Intriguingly, slow respiration variations are also linked to a characteristic rsfMRI network, which is mediated by gamma-band neural activity. In addition, this respiration-related brain network disappears when brain-wide neural activity is silenced at an isoelectrical state, while the respiration is maintained, further confirming the necessary role of neural activity in this network. Taken together, this study identifies a respiration-related brain network underpinned by neural activity, which represents a novel component in the respiration-rsfMRI relationship that is distinct from respiration-related rsfMRI artifacts. It opens a new avenue for investigating the interactions between respiration, neural activity, and resting-state brain networks in both healthy and diseased conditions.
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Affiliation(s)
- Wenyu Tu
- The Neuroscience Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State UniversityUniversity ParkUnited States
- Center for Neurotechnology in Mental Health Research, The Pennsylvania State UniversityUniversity ParkUnited States
| | - Nanyin Zhang
- The Neuroscience Graduate Program, The Huck Institutes of the Life Sciences, The Pennsylvania State UniversityUniversity ParkUnited States
- Center for Neurotechnology in Mental Health Research, The Pennsylvania State UniversityUniversity ParkUnited States
- Department of Biomedical Engineering, The Pennsylvania State UniversityUniversity ParkUnited States
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Xu JQ, Liu QQ, Huang SY, Duan CY, Lu HB, Cao Y, Hu JZ. The lymphatic system: a therapeutic target for central nervous system disorders. Neural Regen Res 2022; 18:1249-1256. [PMID: 36453401 PMCID: PMC9838139 DOI: 10.4103/1673-5374.355741] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
The lymphatic vasculature forms an organized network that covers the whole body and is involved in fluid homeostasis, metabolite clearance, and immune surveillance. The recent identification of functional lymphatic vessels in the meninges of the brain and the spinal cord has provided novel insights into neurophysiology. They emerge as major pathways for fluid exchange. The abundance of immune cells in lymphatic vessels and meninges also suggests that lymphatic vessels are actively involved in neuroimmunity. The lymphatic system, through its role in the clearance of neurotoxic proteins, autoimmune cell infiltration, and the transmission of pro-inflammatory signals, participates in the pathogenesis of a variety of neurological disorders, including neurodegenerative and neuroinflammatory diseases and traumatic injury. Vascular endothelial growth factor C is the master regulator of lymphangiogenesis, a process that is critical for the maintenance of central nervous system homeostasis. In this review, we summarize current knowledge and recent advances relating to the anatomical features and immunological functions of the lymphatic system of the central nervous system and highlight its potential as a therapeutic target for neurological disorders and central nervous system repair.
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Affiliation(s)
- Jia-Qi Xu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan Province, China,Mobile Health Ministry of Education - China Mobile Joint Laboratory, Changsha, Hunan Province, China,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Qian-Qi Liu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan Province, China,Mobile Health Ministry of Education - China Mobile Joint Laboratory, Changsha, Hunan Province, China,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Sheng-Yuan Huang
- Department of Cardiovascular Surgery, The Second Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Chun-Yue Duan
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan Province, China,Mobile Health Ministry of Education - China Mobile Joint Laboratory, Changsha, Hunan Province, China,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China
| | - Hong-Bin Lu
- Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan Province, China,Mobile Health Ministry of Education - China Mobile Joint Laboratory, Changsha, Hunan Province, China,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Department of Sports Medicine, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Correspondence to: Yong Cao, or ; Hong-Bin Lu, ; Jian-Zhong Hu, .
| | - Yong Cao
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan Province, China,Mobile Health Ministry of Education - China Mobile Joint Laboratory, Changsha, Hunan Province, China,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Correspondence to: Yong Cao, or ; Hong-Bin Lu, ; Jian-Zhong Hu, .
| | - Jian-Zhong Hu
- Department of Spine Surgery and Orthopaedics, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Key Laboratory of Organ Injury, Aging and Regenerative Medicine of Hunan Province, Changsha, Hunan Province, China,Mobile Health Ministry of Education - China Mobile Joint Laboratory, Changsha, Hunan Province, China,National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, Hunan Province, China,Correspondence to: Yong Cao, or ; Hong-Bin Lu, ; Jian-Zhong Hu, .
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Monte B, Constantinou S, Koundal S, Lee H, Dai F, Gursky Z, Van Nostrand WE, Darbinyan A, Zlokovic BV, Wardlaw J, Benveniste H. Characterization of perivascular space pathology in a rat model of cerebral small vessel disease by in vivo magnetic resonance imaging. J Cereb Blood Flow Metab 2022; 42:1813-1826. [PMID: 35673963 PMCID: PMC9536121 DOI: 10.1177/0271678x221105668] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 05/09/2022] [Accepted: 05/13/2022] [Indexed: 11/17/2022]
Abstract
One of the most common causes of dementia is cerebral small vessel disease (SVD), which is associated with enlarged perivascular spaces (PVS). Clinically, PVS are visible as hyperintensities on T2-weighted (T2w) magnetic resonance images (MRI). While rodent SVD models exhibit arteriolosclerosis, PVS have not been robustly documented by MRI casting doubts on their clinical relevance. Here we established that the severity of SVD in spontaneously hypertensive stroke prone (SHRSP) rats correlated to 'moderate' SVD in human post-mortem tissue. We then developed two approaches for detecting PVS in SHRSP rats: 1) T2w imaging and 2) T1-weighted imaging with administration of gadoteric acid into cerebrospinal fluid. We applied the two protocols to six Wistar-Kyoto (WKY) control rats and thirteen SHRSP rats at ∼12 month of age. The primary endpoint was the number of hyperintense lesions. We found more hyperintensities on T2w MRI in the SHRSP compared to WKY rats (p-value = 0.023). CSF enhancement with gadoteric acid increased the visibility of PVS-like lesions in SHRSP rats. In some of the SHRSP rats, the MRI hyperintensities corresponded to enlarged PVS on histopathology. The finding of PVS-like hyperintensities on T2w MRI support the SHRSP rat's clinical relevance for studying the underlying pathophysiology of SVD.
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Affiliation(s)
- Brittany Monte
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | | | - Sunil Koundal
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Hedok Lee
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - Feng Dai
- Yale Center for Analytical Sciences, Yale School of Public Health, New Haven, CT, USA
| | - Zachary Gursky
- Department of Anesthesiology, Yale School of Medicine, New Haven, CT, USA
| | - William E Van Nostrand
- George and Anne Ryan Institute for Neuroscience and the Department of Biomedical and Pharmaceutical Sciences, University of Rhode Island, Kingston, RI, USA
| | - Armine Darbinyan
- Department of Pathology, Yale School of Medicine, New Haven, CT, USA
| | - Berislav V Zlokovic
- Department of Physiology and Neuroscience, Keck School of Medicine, University of Southern California, Los Angeles, USA
- Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, USA
| | - Joanna Wardlaw
- Division of Neuroimaging Sciences, Centre for Clinical Brain Sciences; UK Dementia Research Institute Centre at the University of Edinburgh; and Edinburgh Imaging, University of Edinburgh, Edinburgh, UK
| | - 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
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42
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Plá V, Bork P, Harnpramukkul A, Olveda G, Ladrón-de-Guevara A, Giannetto MJ, Hussain R, Wang W, Kelley DH, Hablitz LM, Nedergaard M. A real-time in vivo clearance assay for quantification of glymphatic efflux. Cell Rep 2022; 40:111320. [PMID: 36103828 DOI: 10.1016/j.celrep.2022.111320] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 02/05/2022] [Accepted: 08/16/2022] [Indexed: 11/03/2022] Open
Abstract
Glymphatic fluid transport eliminates metabolic waste from the brain including amyloid-β, yet the methodology for studying efflux remains rudimentary. Here, we develop a method to evaluate glymphatic real-time clearance. Efflux of Direct Blue 53 (DB53, also T-1824 or Evans Blue) injected into the striatum is quantified by imaging the DB53 signal in the vascular compartment, where it is retained due to its high affinity to albumin. The DB53 signal is detectable as early as 15 min after injection and the efflux kinetics are sharply reduced in mice lacking the water channel aquaporin 4 (AQP4). Pharmacokinetic modeling reveal that DB53 efflux is consistent with the existence of two efflux paths, one with fast kinetics (T1/2 = 50 min) and another with slow kinetics (T1/2 = 240 min), in wild-type mice. This in vivo methodology will aid in defining the physiological variables that drive efflux, as well as the impact of brain states or disorders on clearance kinetics.
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Affiliation(s)
- Virginia Plá
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Peter Bork
- Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark
| | - Aurakoch Harnpramukkul
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Genaro Olveda
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Antonio Ladrón-de-Guevara
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Michael J Giannetto
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Rashad Hussain
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Wei Wang
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Douglas H Kelley
- Department of Mechanical Engineering, University of Rochester, Rochester, NY 14627, USA
| | - Lauren M Hablitz
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, University of Rochester Medical Center, Rochester, NY 14642, USA; Center for Translational Neuromedicine, University of Copenhagen, 2200 Copenhagen, Denmark.
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43
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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.
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44
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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.
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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.
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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
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Quintin S, Barpujari A, Mehkri Y, Hernandez J, Lucke-Wold B. The glymphatic system and subarachnoid hemorrhage: disruption and recovery. EXPLORATION OF NEUROPROTECTIVE THERAPY 2022; 2:118-130. [PMID: 35756328 PMCID: PMC9221287 DOI: 10.37349/ent.2022.00023] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/09/2022] [Indexed: 01/01/2023]
Abstract
The glymphatic system, or glial-lymphatic system, is a waste clearance system composed of perivascular channels formed by astrocytes that mediate the clearance of proteins and metabolites from the brain. These channels facilitate the movement of cerebrospinal fluid throughout brain parenchyma and are critical for homeostasis. Disruption of the glymphatic system leads to an accumulation of these waste products as well as increased interstitial fluid in the brain. These phenomena are also seen during and after subarachnoid hemorrhages (SAH), contributing to the brain damage seen after rupture of a major blood vessel. Herein this review provides an overview of the glymphatic system, its disruption during SAH, and its function in recovery following SAH. The review also outlines drugs which target the glymphatic system and may have therapeutic applications following SAH.
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Affiliation(s)
- Stephan Quintin
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Arnav Barpujari
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Yusuf Mehkri
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Jairo Hernandez
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
| | - Brandon Lucke-Wold
- Department of Neurosurgery, College of Medicine, University of Florida, Gainesville, Florida 32610, USA
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47
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Xuan X, Zhou G, Chen C, Shao A, Zhou Y, Li X, Zhou J. Glymphatic System: Emerging Therapeutic Target for Neurological Diseases. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:6189170. [PMID: 35726332 PMCID: PMC9206554 DOI: 10.1155/2022/6189170] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 05/15/2022] [Accepted: 05/24/2022] [Indexed: 11/17/2022]
Abstract
The newly discovered glymphatic system acts as pseudolymphatic vessels subserving brain waste clearance and is functionally dependent on astrocytic aquaporin-4 channels. The glymphatic system primarily functions during sleep as an interchange between cerebrospinal fluid and interstitial fluid, with cerebrospinal fluid flowing into the parenchyma via the perivascular spaces and then exchanging with interstitial fluid. The discovery of meningeal lymphatics helps refine the conceptual framework of glymphatic pathway, as certain waste products collected alongside perivascular spaces ultimately drain into the cervical lymph nodes via meningeal lymphatics, whose function regulates the functioning of the glymphatic system. The glymphatic and meningeal lymphatic systems are critical for the homeostasis of central nervous system, and their malfunctions complicate cerebral dysfunction and diseases. The present review will shed light on the structure, regulation, functions, and interrelationships of the glymphatic system and meningeal lymphatics. We will also expound on their impairments and corresponding targeted intervention in neurodegenerative diseases, traumatic brain injury, stroke, and infectious/autoimmune diseases, offering valuable references for future research.
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Affiliation(s)
- Xianjun Xuan
- Department of Neurology, Hangzhou Ninth People's Hospital, Hangzhou, China
| | - Guoyi Zhou
- The Fourth School of Clinical Medicine, Zhejiang Chinese Medical University, Hangzhou, China
| | - Caihong Chen
- Department of Neurology, Hangzhou Ninth People's Hospital, Hangzhou, China
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yunxiang Zhou
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiaobo Li
- Department of Neurology, Hangzhou Ninth People's Hospital, Hangzhou, China
| | - Jiaqi Zhou
- State Key Laboratory for Diagnosis and Treatment of Infectious Diseases, National Clinical Research Center for Infectious Diseases, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, The First Affiliated Hospital, College of Medicine, Zhejiang University, China
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48
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Newell DW, Nedergaard M, Aaslid R. Physiological Mechanisms and Significance of Intracranial B Waves. Front Neurol 2022; 13:872701. [PMID: 35651339 PMCID: PMC9149212 DOI: 10.3389/fneur.2022.872701] [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: 02/09/2022] [Accepted: 04/20/2022] [Indexed: 12/03/2022] Open
Abstract
Objective Recently published studies have described slow spontaneous cerebral blood flow (CBF) and cerebrospinal fluid (CSF) oscillations measured by magnetic resonance imaging (MRI) as potential drivers of brain glymphatic flow, with a similar frequency as intracranial B-waves. Aiming to establish the relationship between these waveforms, we performed additional analysis of frequency and waveform parameters, of our previously published transcranial Doppler (TCD) and intracranial pressure (ICP) recordings of intracranial B waves, to compare to published MRI frequency measurements of CBF and CSF slow oscillations. Patients and Methods We analyzed digital recordings of B waves in 29 patients with head injury, including middle cerebral artery (MCA) flow velocity (FV), ICP, end tidal CO2, and arterial blood pressure (ABP). A subset of these recordings demonstrated high B wave activity and was further analyzed for parameters including frequency, interaction, and waveform distribution curve features. These measures were compared to published similar measurements of spontaneous CBF and CSF fluctuations evaluated using MRI. Results In patients with at least 10% amplitude B wave activity, the MCA blood flow velocity oscillations comprising the B waves, had a maximum amplitude at 0.0245 Hz, and time derivative a maximum amplitude at 0.035 Hz. The frequency range of the B waves was between 0.6–2.3 cycles per min (0.011-0.038 Hz), which is in the same range as MRI measured CBF slow oscillations, reported in human volunteers. Waveform asymmetry in MCA velocity and ICP cycles during B waves, was also similar to published MRI measured CBF slow oscillations. Cross-correlation analysis showed equivalent time derivatives of FV vs. ICP in B waves, compared to MRI measured CBF slow oscillations vs. CSF flow fluctuations. Conclusions The TCD and ICP recordings of intracranial B waves show a similar frequency range as CBF and CSF flow oscillations measured using MRI, and share other unique morphological wave features. These findings strongly suggest a common physiological mechanism underlying the two classes of phenomena. The slow blood flow and volume oscillations causing intracranial B waves appear to be part of a cascade that may provide a significant driving force for compartmentalized CSF movement and facilitate glymphatic flow.
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Affiliation(s)
- David W Newell
- Department of Neurosurgery, Seattle Neuroscience Institute, Seattle, WA, United States
| | - Maiken Nedergaard
- Department of Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark.,Department of Translational Neuromedicine, University of Rochester Medical School, Rochester, NY, United States
| | - Rune Aaslid
- Department of Neurosurgery, University of Bern, Bern, Switzerland
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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.
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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
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50
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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.
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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
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