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Tran NT, Somers A, Vidinopoulos K, Azman Z, Pham Y, Zahra VA, Chan KYY, Hooper S, Crossley K, Allison BJ, Galinsky R, Polglase GR. The synergistic effects of mechanical ventilation and intrauterine inflammation on cerebral inflammation in preterm fetal sheep. Front Cell Neurosci 2024; 18:1397658. [PMID: 38962513 PMCID: PMC11220153 DOI: 10.3389/fncel.2024.1397658] [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: 03/08/2024] [Accepted: 05/31/2024] [Indexed: 07/05/2024] Open
Abstract
Background Intrauterine inflammation and the requirement for mechanical ventilation independently increase the risk of perinatal brain injury and adverse neurodevelopmental outcomes. We aimed to investigate the effects of mechanical ventilation for 24 h, with and without prior exposure to intrauterine inflammation, on markers of brain inflammation and injury in the preterm sheep brain. Methods Chronically instrumented fetal sheep at ~115 days of gestation were randomly allocated to receive a single intratracheal dose of 1 mg lipopolysaccharide (LPS) or isovolumetric saline, then further randomly allocated 1 h after to receive mechanical ventilation with room air or no mechanical ventilation (unventilated control + saline [UVC, n = 7]; in utero mechanical ventilation + saline [VENT, n = 8], unventilated control + intratracheal LPS [UVC + LPS, n = 7]; in utero ventilation + intratracheal LPS [VENT + LPS, n = 7]). Serial fetal blood and plasma samples were collected throughout the experimental protocol for assessment of blood biochemistry and plasma interleukin (IL)-6 levels. After 24 h of mechanical ventilation, fetal brains were collected for RT-qPCR and immunohistochemical analyses. Results LPS exposure increased numbers of microglia and upregulated pro-inflammatory related genes within the cortical gray matter (GM) and subcortical white matter (SCWM) (pLPS < 0.05). Mechanical ventilation alone increased astrocytic cell density in the periventricular white matter (PVWM) (pVENT = 0.03) but had no effect on pro-inflammatory gene expression. The combination of ventilation and LPS increased plasma IL-6 levels (p < 0.02 vs. UVC and VENT groups), and exacerbated expression of pro-inflammatory-related genes (IL1β, TLR4, PTGS2, CXCL10) and microglial density (p < 0.05 vs. VENT). Conclusion This study demonstrates that 24 h of mechanical ventilation after exposure to intrauterine inflammation increased markers of systemic and brain inflammation and led to the upregulation of pro-inflammatory genes in the white matter. We conclude that 24 h of mechanical ventilation following intrauterine inflammation may precondition the preterm brain toward being more susceptible to inflammation-induced injury.
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Affiliation(s)
- Nhi T. Tran
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Ainsley Somers
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Kayla Vidinopoulos
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Zahrah Azman
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Yen Pham
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Valerie A. Zahra
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Kyra Y. Y. Chan
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
| | - Stuart Hooper
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Kelly Crossley
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Beth J. Allison
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Robert Galinsky
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Obstetrics and Gynaecology, Monash University, Clayton, VIC, Australia
| | - Graeme R. Polglase
- The Ritchie Centre, Hudson Institute of Medical Research, Clayton, VIC, Australia
- Department of Paediatrics, Monash University, Clayton, VIC, Australia
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Anwar MM, Pérez-Martínez L, Pedraza-Alva G. Exploring the Significance of Microglial Phenotypes and Morphological Diversity in Neuroinflammation and Neurodegenerative Diseases: From Mechanisms to Potential Therapeutic Targets. Immunol Invest 2024:1-56. [PMID: 38836373 DOI: 10.1080/08820139.2024.2358446] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/06/2024]
Abstract
Studying various microglial phenotypes and their functions in neurodegenerative diseases is crucial due to the intricate nature of their phenomics and their vital immunological role. Microglia undergo substantial phenomic changes, encompassing morphological, transcriptional, and functional aspects, resulting in distinct cell types with diverse structures, functions, properties, and implications. The traditional classification of microglia as ramified, M1 (proinflammatory), or M2 (anti-inflammatory) phenotypes is overly simplistic, failing to capture the wide range of recently identified microglial phenotypes in various brain regions affected by neurodegenerative diseases. Altered and activated microglial phenotypes deviating from the typical ramified structure are significant features of many neurodegenerative conditions. Understanding the precise role of each microglial phenotype is intricate and sometimes contradictory. This review specifically focuses on elucidating recent modifications in microglial phenotypes within neurodegenerative diseases. Recognizing the heterogeneity of microglial phenotypes in diseased states can unveil novel therapeutic strategies for targeting microglia in neurodegenerative diseases. Moreover, the exploration of the use of healthy isolated microglia to mitigate disease progression has provided an innovative perspective. In conclusion, this review discusses the dynamic landscape of mysterious microglial phenotypes, emphasizing the need for a nuanced understanding to pave the way for innovative therapeutic strategies for neurodegenerative diseases.
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Affiliation(s)
- Mai M Anwar
- Department of Biochemistry, National Organization for Drug Control and Research (NODCAR)/Egyptian Drug Authority (EDA), Cairo, Egypt
| | - Leonor Pérez-Martínez
- Neuroimmunobiology Laboratory, Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Cuernavaca, Morelos, Mexico
| | - Gustavo Pedraza-Alva
- Neuroimmunobiology Laboratory, Department of Molecular Medicine and Bioprocesses, Institute of Biotechnology, National Autonomous University of Mexico, Cuernavaca, Morelos, Mexico
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Abdullahi A, Etoom M, Badaru UM, Elibol N, Abuelsamen AA, Alawneh A, Zakari UU, Saeys W, Truijen S. Vagus nerve stimulation for the treatment of epilepsy: things to note on the protocols, the effects and the mechanisms of action. Int J Neurosci 2024; 134:560-569. [PMID: 36120993 DOI: 10.1080/00207454.2022.2126776] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/19/2022] [Accepted: 08/26/2022] [Indexed: 10/14/2022]
Abstract
Epilepsy is a chronic brain disorder that is characterized by repetitive un-triggered seizures that occur severally within 24 h or more. Non-pharmacological methods for the management of epilepsy were discussed. The non-pharmacological methods include the vagus nerve stimulation (VNS) which is subdivided into invasive and non-invasive techniques. For the non-invasive techniques, the auricular VNS, stimulation of the cervical branch of vagus nerve in the neck, manual massage of the neck, and respiratory vagal nerve stimulation were discussed. Similarly, the stimulation parameters used and the mechanisms of actions through which VNS improves seizures were also discussed. Use of VNS to reduce seizure frequency has come a long way. However, considering the cost and side effects of the invasive method, non-invasive techniques should be given a renewed attention. In particular, respiratory vagal nerve stimulation should be considered. In doing this, the patients should for instance carry out slow-deep breathing exercise 6 to 8 times every 3 h during the waking hours. Slow-deep breathing can be carried out by the patients on their own; therefore this can serve as a form of self-management.HIGHLIGHTSEpilepsy can interfere with the patients' ability to carry out their daily activities and ultimately affect their quality of life.Medications are used to manage epilepsy; but they often have their serious side effects.Vagus nerve stimulation (VNS) is gaining ground especially in the management of refractory epilepsy.The VNS is administered through either the invasive or the non-invasive methodsThe invasive method of VNS like the medication has potential side effects, and can be costly.The non-invasive method includes auricular VNS, stimulation of the neck muscles and skin and respiratory vagal nerve stimulation via slow-deep breathing exercises.The respiratory vagal nerve stimulation via slow-deep breathing exercises seems easy to administer even by the patients themselves.Consequently, it is our opinion that patients with epilepsy be made to carry out slow-deep breathing exercise 6-8 times every 3 h during the waking hours.
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Affiliation(s)
- Auwal Abdullahi
- Department of Physiotherapy, Bayero University Kano, Nigeria
- Department of Rehabilitation Sciences and Physiotherapy, University of Antwerp, Antwerp, Belgium
| | - Mohammad Etoom
- Department of Physiotherapy, Aqaba University of Technology, Aqaba, Jordan
| | | | - Nuray Elibol
- Department of Physiotherapy and Rehabilitation Sciences, Ege University, Izmir, Turkey
| | | | - Anoud Alawneh
- Department of Physiotherapy, Aqaba University of Technology, Aqaba, Jordan
| | - Usman Usman Zakari
- Department of Physiotherapy, Federal Medical Center, Birnin Kudu, Jigawa State, Nigeria
| | - Wim Saeys
- Department of Rehabilitation Sciences and Physiotherapy, University of Antwerp, Antwerp, Belgium
| | - Steven Truijen
- Department of Rehabilitation Sciences and Physiotherapy, University of Antwerp, Antwerp, Belgium
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Kim HS, Jung H, Park YH, Heo SH, Kim S, Moon M. Skin-brain axis in Alzheimer's disease - Pathologic, diagnostic, and therapeutic implications: A Hypothetical Review. Aging Dis 2024:AD.2024.0406. [PMID: 38739932 DOI: 10.14336/ad.2024.0406] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 04/06/2024] [Indexed: 05/16/2024] Open
Abstract
The dynamic interaction between the brain and the skin is termed the 'skin-brain axis.' Changes in the skin not only reflect conditions in the brain but also exert direct and indirect effects on the brain. Interestingly, the connection between the skin and brain is crucial for understanding aging and neurodegenerative diseases. Several studies have shown an association between Alzheimer's disease (AD) and various skin disorders, such as psoriasis, bullous pemphigoid, and skin cancer. Previous studies have shown a significantly increased risk of new-onset AD in patients with psoriasis. In contrast, skin cancer may reduce the risk of developing AD. Accumulating evidence suggests an interaction between skin disease and AD; however, AD-associated pathological changes mediated by the skin-brain axis are not yet clearly defined. While some studies have reported on the diagnostic implications of the skin-brain axis in AD, few have discussed its potential therapeutic applications. In this review, we address the pathological changes mediated by the skin-brain axis in AD. Furthermore, we summarize (1) the diagnostic implications elucidated through the role of the skin-brain axis in AD and (2) the therapeutic implications for AD based on the skin-brain axis. Our review suggests that a potential therapeutic approach targeting the skin-brain axis will enable significant advances in the treatment of AD.
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Affiliation(s)
- Hyeon Soo Kim
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Korea
| | - Haram Jung
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Korea
| | - Yong Ho Park
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Korea
| | - Su-Hak Heo
- Department of Medicinal Bioscience, Konkuk University (Glocal Campus), Chungcheongbuk-do 27478, Korea
| | - Sujin Kim
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Korea
- Research Institute for Dementia Science, Konyang University, Daejeon 35365, Korea
| | - Minho Moon
- Department of Biochemistry, College of Medicine, Konyang University, Daejeon 35365, Korea
- Research Institute for Dementia Science, Konyang University, Daejeon 35365, Korea
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Deng W, Yi P, Xiong Y, Ying J, Lin Y, Dong Y, Wei G, Wang X, Hua F. Gut Metabolites Acting on the Gut-Brain Axis: Regulating the Functional State of Microglia. Aging Dis 2024; 15:480-502. [PMID: 37548933 PMCID: PMC10917527 DOI: 10.14336/ad.2023.0727] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 07/27/2023] [Indexed: 08/08/2023] Open
Abstract
The gut-brain axis is a communication channel that mediates a complex interplay of intestinal flora with the neural, endocrine, and immune systems, linking gut and brain functions. Gut metabolites, a group of small molecules produced or consumed by biochemical processes in the gut, are involved in central nervous system regulation via the highly interconnected gut-brain axis affecting microglia indirectly by influencing the structure of the gut-brain axis or directly affecting microglia function and activity. Accordingly, pathological changes in the central nervous system are connected with changes in intestinal metabolite levels as well as altered microglia function and activity, which may contribute to the pathological process of each neuroinflammatory condition. Here, we discuss the mechanisms by which gut metabolites, for instance, the bile acids, short-chain fatty acids, and tryptophan metabolites, regulate the structure of each component of the gut-brain axis, and explore the important roles of gut metabolites in the central nervous system from the perspective of microglia. At the same time, we highlight the roles of gut metabolites affecting microglia in the pathogenesis of neurodegenerative diseases and neurodevelopmental disorders. Understanding the relationship between microglia, gut microbiota, neuroinflammation, and neurodevelopmental disorders will help us identify new strategies for treating neuropsychiatric disorders.
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Affiliation(s)
- Wenze Deng
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Pengcheng Yi
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Yanhong Xiong
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Jun Ying
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Yue Lin
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Yao Dong
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Gen Wei
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
| | - Xifeng Wang
- Department of Anesthesiology, the First Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
| | - Fuzhou Hua
- Department of Anesthesiology, the Second Affiliated Hospital of Nanchang University, Nanchang, Jiangxi, China.
- Key Laboratory of Anesthesiology of Jiangxi Province, Nanchang City, Jiangxi, China.
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Yan L, Li H, Qian Y, Zhang J, Cong S, Zhang X, Wu L, Wang Y, Wang M, Yu T. Transcutaneous vagus nerve stimulation: a new strategy for Alzheimer's disease intervention through the brain-gut-microbiota axis? Front Aging Neurosci 2024; 16:1334887. [PMID: 38476661 PMCID: PMC10927744 DOI: 10.3389/fnagi.2024.1334887] [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: 11/08/2023] [Accepted: 02/15/2024] [Indexed: 03/14/2024] Open
Abstract
Transcutaneous vagus nerve stimulation (tVNS) is an emerging non-invasive technique designed to stimulate branches of the vagus nerve distributed over the body surface. Studies suggest a correlation between the brain-gut-microbiota (BGM) axis and the pathogenesis of Alzheimer's disease (AD). The BGM axis represents a complex bidirectional communication system, with the vagus nerve being a crucial component. Therefore, non-invasive electrical stimulation of the vagus nerve might have the potential to modify-most of the time probably in a non-physiological way-the signal transmission within the BGM axis, potentially influencing the progression or symptoms of AD. This review explores the interaction between percutaneous vagus nerve stimulation and the BGM axis, emphasizing its potential effects on AD. It examines various aspects, such as specific brain regions, gut microbiota composition, maintenance of intestinal environmental homeostasis, inflammatory responses, brain plasticity, and hypothalamic-pituitary-adrenal (HPA) axis regulation. The review suggests that tVNS could serve as an effective strategy to modulate the BGM axis and potentially intervene in the progression or treatment of Alzheimer's disease in the future.
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Affiliation(s)
- Long Yan
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
- Graduate Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Hong Li
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
- Graduate Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yulin Qian
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
| | - Junfeng Zhang
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
- Graduate Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Shan Cong
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
- Graduate Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Xuemin Zhang
- Graduate Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Linna Wu
- Graduate Department, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Yu Wang
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
| | - Meng Wang
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
| | - Tao Yu
- The First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, Tianjin, China
- National Clinical Research Center for Acupuncture and Moxibustion, Tianjin, China
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Liu Y, Jia N, Tang C, Long H, Wang J. Microglia in Microbiota-Gut-Brain Axis: A Hub in Epilepsy. Mol Neurobiol 2024:10.1007/s12035-024-04022-w. [PMID: 38366306 DOI: 10.1007/s12035-024-04022-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Accepted: 02/06/2024] [Indexed: 02/18/2024]
Abstract
There is growing concern about the role of the microbiota-gut-brain axis in neurological illnesses, and it makes sense to consider microglia as a critical component of this axis in the context of epilepsy. Microglia, which reside in the central nervous system, are dynamic guardians that monitor brain homeostasis. Microglia receive information from the gut microbiota and function as hubs that may be involved in triggering epileptic seizures. Vagus nerve bridges the communication in the axis. Essential axis signaling molecules, such as gamma-aminobutyric acid, 5-hydroxytryptamin, and short-chain fatty acids, are currently under investigation for their participation in drug-resistant epilepsy (DRE). In this review, we explain how vagus nerve connects the gut microbiota to microglia in the brain and discuss the emerging concepts derived from this interaction. Understanding microbiota-gut-brain axis in epilepsy brings hope for DRE therapies. Future treatments can focus on the modulatory effect of the axis and target microglia in solving DRE.
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Affiliation(s)
- Yuyang Liu
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- The First Clinical Medicine College, Southern Medical University, Guangzhou, China
- Neural Networks Surgery Team, Southern Medical University, Guangzhou, China
| | - Ningkang Jia
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Neural Networks Surgery Team, Southern Medical University, Guangzhou, China
- The Second Clinical Medicine College, Southern Medical University, Guangzhou, China
| | - Chuqi Tang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- The First Clinical Medicine College, Southern Medical University, Guangzhou, China
- Neural Networks Surgery Team, Southern Medical University, Guangzhou, China
| | - Hao Long
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- The First Clinical Medicine College, Southern Medical University, Guangzhou, China
| | - Jun Wang
- Department of Neurosurgery, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
- The First Clinical Medicine College, Southern Medical University, Guangzhou, China.
- Neural Networks Surgery Team, Southern Medical University, Guangzhou, China.
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8
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Conn KA, Borsom EM, Cope EK. Implications of microbe-derived ɣ-aminobutyric acid (GABA) in gut and brain barrier integrity and GABAergic signaling in Alzheimer's disease. Gut Microbes 2024; 16:2371950. [PMID: 39008552 PMCID: PMC11253888 DOI: 10.1080/19490976.2024.2371950] [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: 03/13/2024] [Accepted: 06/19/2024] [Indexed: 07/17/2024] Open
Abstract
The gut microbial ecosystem communicates bidirectionally with the brain in what is known as the gut-microbiome-brain axis. Bidirectional signaling occurs through several pathways including signaling via the vagus nerve, circulation of microbial metabolites, and immune activation. Alterations in the gut microbiota are implicated in Alzheimer's disease (AD), a progressive neurodegenerative disease. Perturbations in gut microbial communities may affect pathways within the gut-microbiome-brain axis through altered production of microbial metabolites including ɣ-aminobutyric acid (GABA), the primary inhibitory mammalian neurotransmitter. GABA has been shown to act on gut integrity through modulation of gut mucins and tight junction proteins and may be involved in vagus nerve signal inhibition. The GABAergic signaling pathway has been shown to be dysregulated in AD, and may be responsive to interventions. Gut microbial production of GABA is of recent interest in neurological disorders, including AD. Bacteroides and Lactic Acid Bacteria (LAB), including Lactobacillus, are predominant producers of GABA. This review highlights how temporal alterations in gut microbial communities associated with AD may affect the GABAergic signaling pathway, intestinal barrier integrity, and AD-associated inflammation.
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Affiliation(s)
- Kathryn A. Conn
- Center for Applied Microbiome Sciences, The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Emily M. Borsom
- Center for Data-Driven Discovery for Biology, Allen Institute, Seattle, WA, USA
| | - Emily K. Cope
- Center for Applied Microbiome Sciences, The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
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Tyliszczak M, Wiatrak B, Danielewski M, Szeląg A, Kucharska AZ, Sozański T. Does a pickle a day keep Alzheimer's away? Fermented food in Alzheimer's disease: A review. Exp Gerontol 2023; 184:112332. [PMID: 37967591 DOI: 10.1016/j.exger.2023.112332] [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: 09/18/2023] [Revised: 11/09/2023] [Accepted: 11/12/2023] [Indexed: 11/17/2023]
Abstract
Fermented food is commonly viewed as healthy, mostly due to its probiotic and digestion-enhancing properties and recently it has been examined with regard to the development of new therapeutic and preventive measures for Alzheimer's disease. Fermented food has been shown to have anti-inflammatory and antioxidant properties and to alter the gut microbiota. However, the exact pathogenesis of Alzheimer's disease is still unknown and its connections to systemic inflammation and gut dysbiosis, as potential targets of fermented food, require further investigation. Therefore, to sum up the current knowledge, this article reviews recent research on the pathogenesis of Alzheimer's disease with emphasis on the role of the gut-brain axis and studies examining the use of fermented foods. The analysis of the fermented food research includes clinical and preclinical in vivo and in vitro studies. The fermented food studies have shown promising effects on amyloid-β metabolism, inflammation, and cognitive impairment in animals and humans. Fermented food has great potential in developing new approaches to Alzheimer's disease treatment.
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Affiliation(s)
- Michał Tyliszczak
- Department of Pharmacology, Wroclaw Medical University, Wrocław, Poland.
| | - Benita Wiatrak
- Department of Pharmacology, Wroclaw Medical University, Wrocław, Poland
| | | | - Adam Szeląg
- Department of Pharmacology, Wroclaw Medical University, Wrocław, Poland
| | - Alicja Z Kucharska
- Department of Fruit, Vegetable, and Plant Nutraceutical Technology, Wroclaw University of Environmental and Life Sciences, Wrocław, Poland
| | - Tomasz Sozański
- Department of Preclinical Sciences, Pharmacology and Medical Diagnostics, Faculty of Medicine, Wroclaw University of Science and Technology, Wrocław, Poland
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Trifilio E, Shortell D, Olshan S, O’Neal A, Coyne J, Lamb D, Porges E, Williamson J. Impact of transcutaneous vagus nerve stimulation on healthy cognitive and brain aging. Front Neurosci 2023; 17:1184051. [PMID: 37575296 PMCID: PMC10416636 DOI: 10.3389/fnins.2023.1184051] [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: 03/10/2023] [Accepted: 05/02/2023] [Indexed: 08/15/2023] Open
Abstract
Evidence for clinically meaningful benefits of transcutaneous vagus nerve stimulation (VNS) has been rapidly accumulating over the past 15 years. This relatively novel non-invasive brain stimulation technique has been applied to a wide range of neuropsychiatric disorders including schizophrenia, obsessive compulsive disorder, panic disorder, post-traumatic stress disorder, bipolar disorder, and Alzheimer's disease. More recently, non-invasive forms of VNS have allowed for investigations within healthy aging populations. These results offer insight into protocol considerations specific to older adults and how to translate those results into effective clinical trials and, ultimately, effective clinical care. In this review, we characterize the possible mechanisms by which non-invasive VNS may promote healthy aging (e.g., neurotransmitter effects, inflammation regulation, functional connectivity changes), special considerations for applying non-invasive VNS in an older adult population (e.g., vagus nerve changes with age), and how non-invasive VNS may be used in conjunction with existing behavioral interventions (e.g., cognitive behavioral therapy, cognitive training) to promote healthy emotional and cognitive aging.
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Affiliation(s)
- Erin Trifilio
- Center for OCD and Anxiety Related Disorders, Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, United States
- Brain Rehabilitation and Research Center, Malcom Randall VAMC, Gainesville, FL, United States
- Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States
| | - Destin Shortell
- Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Sarah Olshan
- Brain Rehabilitation and Research Center, Malcom Randall VAMC, Gainesville, FL, United States
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Alexandria O’Neal
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Jozee Coyne
- Center for OCD and Anxiety Related Disorders, Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, United States
- Brain Rehabilitation and Research Center, Malcom Randall VAMC, Gainesville, FL, United States
| | - Damon Lamb
- Center for OCD and Anxiety Related Disorders, Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, United States
- Brain Rehabilitation and Research Center, Malcom Randall VAMC, Gainesville, FL, United States
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - Eric Porges
- Brain Rehabilitation and Research Center, Malcom Randall VAMC, Gainesville, FL, United States
- Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
| | - John Williamson
- Center for OCD and Anxiety Related Disorders, Department of Psychiatry, McKnight Brain Institute, College of Medicine, University of Florida, Gainesville, FL, United States
- Brain Rehabilitation and Research Center, Malcom Randall VAMC, Gainesville, FL, United States
- Department of Clinical and Health Psychology, College of Public Health and Health Professions, University of Florida, Gainesville, FL, United States
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
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11
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Ben-Azu B, del Re EC, VanderZwaag J, Carrier M, Keshavan M, Khakpour M, Tremblay MÈ. Emerging epigenetic dynamics in gut-microglia brain axis: experimental and clinical implications for accelerated brain aging in schizophrenia. Front Cell Neurosci 2023; 17:1139357. [PMID: 37256150 PMCID: PMC10225712 DOI: 10.3389/fncel.2023.1139357] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 04/27/2023] [Indexed: 06/01/2023] Open
Abstract
Brain aging, which involves a progressive loss of neuronal functions, has been reported to be premature in probands affected by schizophrenia (SCZ). Evidence shows that SCZ and accelerated aging are linked to changes in epigenetic clocks. Recent cross-sectional magnetic resonance imaging analyses have uncovered reduced brain reserves and connectivity in patients with SCZ compared to typically aging individuals. These data may indicate early abnormalities of neuronal function following cyto-architectural alterations in SCZ. The current mechanistic knowledge on brain aging, epigenetic changes, and their neuropsychiatric disease association remains incomplete. With this review, we explore and summarize evidence that the dynamics of gut-resident bacteria can modulate molecular brain function and contribute to age-related neurodegenerative disorders. It is known that environmental factors such as mode of birth, dietary habits, stress, pollution, and infections can modulate the microbiota system to regulate intrinsic neuronal activity and brain reserves through the vagus nerve and enteric nervous system. Microbiota-derived molecules can trigger continuous activation of the microglial sensome, groups of receptors and proteins that permit microglia to remodel the brain neurochemistry based on complex environmental activities. This remodeling causes aberrant brain plasticity as early as fetal developmental stages, and after the onset of first-episode psychosis. In the central nervous system, microglia, the resident immune surveillance cells, are involved in neurogenesis, phagocytosis of synapses and neurological dysfunction. Here, we review recent emerging experimental and clinical evidence regarding the gut-brain microglia axis involvement in SCZ pathology and etiology, the hypothesis of brain reserve and accelerated aging induced by dietary habits, stress, pollution, infections, and other factors. We also include in our review the possibilities and consequences of gut dysbiosis activities on microglial function and dysfunction, together with the effects of antipsychotics on the gut microbiome: therapeutic and adverse effects, role of fecal microbiota transplant and psychobiotics on microglial sensomes, brain reserves and SCZ-derived accelerated aging. We end the review with suggestions that may be applicable to the clinical setting. For example, we propose that psychobiotics might contribute to antipsychotic-induced therapeutic benefits or adverse effects, as well as reduce the aging process through the gut-brain microglia axis. Overall, we hope that this review will help increase the understanding of SCZ pathogenesis as related to chronobiology and the gut microbiome, as well as reveal new concepts that will serve as novel treatment targets for SCZ.
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Affiliation(s)
- Benneth Ben-Azu
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Pharmacology, Faculty of Basic Medical Sciences, College of Health Sciences, Delta State University, Abraka, Nigeria
| | - Elisabetta C. del Re
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States
- VA Boston Healthcare System, Brockton, MA, United States
- Beth Israel Deaconess Medical Center, Boston, MA, United States
| | - Jared VanderZwaag
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Micaël Carrier
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Matcheri Keshavan
- Department of Psychiatry, Harvard Medical School, Boston, MA, United States
- Beth Israel Deaconess Medical Center, Boston, MA, United States
| | | | - Marie-Ève Tremblay
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Axe Neurosciences, Centre de Recherche du CHU de Québec, Université Laval, Québec City, QC, Canada
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Centre for Advanced Materials and Related Technology (CAMTEC), Institute on Aging and Lifelong Health (IALH), University of Victoria, Victoria, BC, Canada
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12
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Oh M, Weaver DF. Alzheimer's disease as a fundamental disease of information processing systems: An information theory perspective. Front Neurosci 2023; 17:1106623. [PMID: 36845437 PMCID: PMC9950401 DOI: 10.3389/fnins.2023.1106623] [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: 11/24/2022] [Accepted: 01/30/2023] [Indexed: 02/12/2023] Open
Abstract
The human brain is a dynamic multiplex of information, both neural (neurotransmitter-to-neuron, involving 1.5×1015 action potentials per minute) and immunological (cytokine-to-microglia, providing continuous immune surveillance via 1.5×1010 immunocompetent cells). This conceptualization highlights the opportunity of exploiting "information" not only in the mechanistic understanding of brain pathology, but also as a potential therapeutic modality. Arising from its parallel yet interconnected proteopathic-immunopathic pathogeneses, Alzheimer's disease (AD) enables an exploration of the mechanistic and therapeutic contributions of information as a physical process central to brain disease progression. This review first considers the definition of information and its relevance to neurobiology and thermodynamics. Then we focus on the roles of information in AD using its two classical hallmarks. We assess the pathological contributions of β-amyloid peptides to synaptic dysfunction and reconsider this as a source of noise that disrupts information transfer between presynaptic and postsynaptic neurons. Also, we treat the triggers that activate cytokine-microglial brain processes as information-rich three-dimensional patterns, including pathogen-associated molecular patterns and damage-associated molecular patterns. There are structural and functional similarities between neural and immunological information with both fundamentally contributing to brain anatomy and pathology in health and disease. Finally, the role of information as a therapeutic for AD is introduced, particularly cognitive reserve as a prophylactic protective factor and cognitive therapy as a therapeutic contributor to the comprehensive management of ongoing dementia.
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Affiliation(s)
- Myongin Oh
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Donald F. Weaver
- Krembil Research Institute, University Health Network, Toronto, ON, Canada,Department of Chemistry, University of Toronto, Toronto, ON, Canada,Department of Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada,Department of Medicine (Neurology), University of Toronto, Toronto, ON, Canada,*Correspondence: Donald F. Weaver,
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13
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Chandra S, Sisodia SS, Vassar RJ. The gut microbiome in Alzheimer's disease: what we know and what remains to be explored. Mol Neurodegener 2023; 18:9. [PMID: 36721148 PMCID: PMC9889249 DOI: 10.1186/s13024-023-00595-7] [Citation(s) in RCA: 60] [Impact Index Per Article: 60.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2022] [Accepted: 01/06/2023] [Indexed: 02/02/2023] Open
Abstract
Alzheimer's disease (AD), the most common cause of dementia, results in a sustained decline in cognition. There are currently few effective disease modifying therapies for AD, but insights into the mechanisms that mediate the onset and progression of disease may lead to new, effective therapeutic strategies. Amyloid beta oligomers and plaques, tau aggregates, and neuroinflammation play a critical role in neurodegeneration and impact clinical AD progression. The upstream modulators of these pathological features have not been fully clarified, but recent evidence indicates that the gut microbiome (GMB) may have an influence on these features and therefore may influence AD progression in human patients. In this review, we summarize studies that have identified alterations in the GMB that correlate with pathophysiology in AD patients and AD mouse models. Additionally, we discuss findings with GMB manipulations in AD models and potential GMB-targeted therapeutics for AD. Lastly, we discuss diet, sleep, and exercise as potential modifiers of the relationship between the GMB and AD and conclude with future directions and recommendations for further studies of this topic.
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Affiliation(s)
- Sidhanth Chandra
- grid.16753.360000 0001 2299 3507Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 USA ,grid.16753.360000 0001 2299 3507Medical Scientist Training Program, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 USA
| | - Sangram S. Sisodia
- grid.170205.10000 0004 1936 7822Department of Neurobiology, University of Chicago, Chicago, IL 60637 USA
| | - Robert J. Vassar
- grid.16753.360000 0001 2299 3507Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611 USA
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14
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Xu H, Jin T, Zhang R, Xie H, Zhuang C, Zhang Y, Kong D, Xiao G, Yu X. Cerebral cortex and hippocampus neural interaction during vagus nerve stimulation under in vivo large-scale imaging. Front Neurosci 2023; 17:1131063. [PMID: 36937685 PMCID: PMC10017477 DOI: 10.3389/fnins.2023.1131063] [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: 12/24/2022] [Accepted: 02/13/2023] [Indexed: 03/06/2023] Open
Abstract
Objective The purpose of this study was to study mechanisms of VNS modulation from a single neuron perspective utilizing a practical observation platform with single neuron resolution and widefield, real-time imaging coupled with an animal model simultaneously exposing the cerebral cortex and the hippocampus. Methods We utilized the observation platform characterized of widefield of view, real-time imaging, and high spatiotemporal resolution to obtain the neuronal activities in the cerebral cortex and the hippocampus during VNS in awake states and under anesthesia. Results Some neurons in the hippocampus were tightly related to VNS modulation, and varied types of neurons showed distinct responses to VNS modulation. Conclusion We utilized such an observation platform coupled with a novel animal model to obtain more information on neuron activities in the cerebral cortex and the hippocampus, providing an effective method to further study the mechanisms of therapeutic effects modulated by VNS.
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Affiliation(s)
- Hanyun Xu
- Chinese PLA Medical School, Beijing, China
- Department of Neurosurgery, The First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Tingting Jin
- Pulmonary and Critical Care Department, Wuhu Hospital of East China Normal University, Wuhu, Anhui, China
| | - Rujin Zhang
- Department of Anesthesiology, The First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Hao Xie
- Department of Automation, Tsinghua University, Beijing, China
| | - Chaowei Zhuang
- Department of Automation, Tsinghua University, Beijing, China
| | - Yanyang Zhang
- Department of Neurosurgery, The First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Dongsheng Kong
- Department of Neurosurgery, The First Medical Center of Chinese PLA General Hospital, Beijing, China
| | - Guihua Xiao
- Department of Automation, Tsinghua University, Beijing, China
- BNRist, Tsinghua University, Beijing, China
- *Correspondence: Guihua Xiao,
| | - Xinguang Yu
- Department of Neurosurgery, The First Medical Center of Chinese PLA General Hospital, Beijing, China
- Xinguang Yu,
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15
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Zhang C, Xue P, Zhang H, Tan C, Zhao S, Li X, Sun L, Zheng H, Wang J, Zhang B, Lang W. Gut brain interaction theory reveals gut microbiota mediated neurogenesis and traditional Chinese medicine research strategies. Front Cell Infect Microbiol 2022; 12:1072341. [PMID: 36569198 PMCID: PMC9772886 DOI: 10.3389/fcimb.2022.1072341] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2022] [Accepted: 11/07/2022] [Indexed: 12/13/2022] Open
Abstract
Adult neurogenesis is the process of differentiation of neural stem cells (NSCs) into neurons and glial cells in certain areas of the adult brain. Defects in neurogenesis can lead to neurodegenerative diseases, mental disorders, and other maladies. This process is directionally regulated by transcription factors, the Wnt and Notch pathway, the extracellular matrix, and various growth factors. External factors like stress, physical exercise, diet, medications, etc., affect neurogenesis and the gut microbiota. The gut microbiota may affect NSCs through vagal, immune and chemical pathways, and other pathways. Traditional Chinese medicine (TCM) has been proven to affect NSCs proliferation and differentiation and can regulate the abundance and metabolites produced by intestinal microorganisms. However, the underlying mechanisms by which these factors regulate neurogenesis through the gut microbiota are not fully understood. In this review, we describe the recent evidence on the role of the gut microbiota in neurogenesis. Moreover, we hypothesize on the characteristics of the microbiota-gut-brain axis based on bacterial phyla, including microbiota's metabolites, and neuronal and immune pathways while providing an outlook on TCM's potential effects on adult neurogenesis by regulating gut microbiota.
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Affiliation(s)
- Chenxi Zhang
- Basic Medical Science College, Qiqihar Medical University, Qiqihar, China
| | - Peng Xue
- Medical School of Nantong University, Nantong University, Nantong, China
| | - Haiyan Zhang
- Basic Medical Science College, Qiqihar Medical University, Qiqihar, China
| | - Chenxi Tan
- Department of Infection Control, The Second Affiliated Hospital of Qiqihar Medical University, Qiqihar, China
| | - Shiyao Zhao
- Department of Nuclear Medicine, The Third Affiliated Hospital of Qiqihar Medical University, Qiqihar, China
| | - Xudong Li
- Department of Breast Surgery, Harbin Medical University Cancer Hospital, Harbin, China
| | - Lihui Sun
- Basic Medical Science College, Qiqihar Medical University, Qiqihar, China
| | - Huihui Zheng
- Basic Medical Science College, Qiqihar Medical University, Qiqihar, China
| | - Jun Wang
- The Academic Affairs Office, Qiqihar Medical University, Qiqihar, China
| | - Baoling Zhang
- Department of Operating Room, Qiqihar First Hospital, Qiqihar, China
| | - Weiya Lang
- Basic Medical Science College, Qiqihar Medical University, Qiqihar, China,*Correspondence: Weiya Lang,
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16
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D'Alessandro G, Marrocco F, Limatola C. Microglial cells: Sensors for neuronal activity and microbiota-derived molecules. Front Immunol 2022; 13:1011129. [PMID: 36426369 PMCID: PMC9679421 DOI: 10.3389/fimmu.2022.1011129] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Accepted: 10/24/2022] [Indexed: 11/26/2023] Open
Abstract
Microglial cells play pleiotropic homeostatic activities in the brain, during development and in adulthood. Microglia regulate synaptic activity and maturation, and continuously patrol brain parenchyma monitoring for and reacting to eventual alterations or damages. In the last two decades microglia were given a central role as an indicator to monitor the inflammatory state of brain parenchyma. However, the recent introduction of single cell scRNA analyses in several studies on the functional role of microglia, revealed a not-negligible spatio-temporal heterogeneity of microglial cell populations in the brain, both during healthy and in pathological conditions. Furthermore, the recent advances in the knowledge of the mechanisms involved in the modulation of cerebral activity induced by gut microbe-derived molecules open new perspectives for deciphering the role of microglial cells as possible mediators of these interactions. The aim of this review is to summarize the most recent studies correlating gut-derived molecules and vagal stimulation, as well as dysbiotic events, to alteration of brain functioning, and the contribution of microglial cells.
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Affiliation(s)
- Giuseppina D'Alessandro
- Department of Physiology and Pharmacology, Laboratory affiliated to Pasteur Italy, University of Rome La Sapienza, Rome, Italy
- IRCCS Neuromed, Pozzilli (IS), Italy
| | - Francesco Marrocco
- Department of Physiology and Pharmacology, Laboratory affiliated to Pasteur Italy, University of Rome La Sapienza, Rome, Italy
| | - Cristina Limatola
- Department of Physiology and Pharmacology, Laboratory affiliated to Pasteur Italy, University of Rome La Sapienza, Rome, Italy
- IRCCS Neuromed, Pozzilli (IS), Italy
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17
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Xie X, Zhang N, Fu J, Wang Z, Ye Z, Liu Z. The potential for traditional Chinese therapy in treating sleep disorders caused by COVID-19 through the cholinergic anti-inflammatory pathway. Front Pharmacol 2022; 13:1009527. [PMID: 36299906 PMCID: PMC9589290 DOI: 10.3389/fphar.2022.1009527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Accepted: 09/23/2022] [Indexed: 11/23/2022] Open
Abstract
Since the outbreak of Coronavirus disease (COVID-19) in 2019, it has spread rapidly across the globe. Sleep disorders caused by COVID-19 have become a major concern for COVID-19 patients and recovered patients. So far, there’s no effective therapy on this. Traditional Chinese therapy (TCT) has a great effect on sleep disorders, with rare side effects and no obvious withdrawal symptoms. The cholinergic anti-inflammatory pathway, a neuroregulatory pathway in the central nervous system that uses cholinergic neurons and neurotransmitters to suppress inflammatory responses, has been reported to be associated with sleep disorders and psychiatric symptoms. Many studies have shown that TCT activates the cholinergic anti-inflammatory pathway (CAP), inhibits inflammation, and relieves associated symptoms. Therefore, we believe that TCT may be a potential therapeutic strategy to alleviate sleep disorders induced by COVID-19 through CAP. In this review, we analyzed the relationship between cytokine storm induced by Coronavirus and sleep disorders, explained the influence of CAP on sleep disorders, discussed the TCT’s effect on CAP, and summarized the treatment effect of TCT on sleep disorders. Based on these practical researches and theoretical basis, we propose potential strategies to effectively improve the sleep disorders caused by COVID-19.
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Affiliation(s)
- Xiaoxia Xie
- Institute of Regenerative and Reconstructive Medicine, Med-X Institute, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi University of Chinese Medicine, Xian yang, China
| | - Nana Zhang
- Institute of Regenerative and Reconstructive Medicine, Med-X Institute, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- National Local Joint Engineering Research Center for Precision Surgery & Regenerative Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi Provincial Center for Regenerative Medicine and Surgical Engineering, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Jingya Fu
- Institute of Regenerative and Reconstructive Medicine, Med-X Institute, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi University of Chinese Medicine, Xian yang, China
| | - Zhenzhi Wang
- Institute of Regenerative and Reconstructive Medicine, Med-X Institute, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi University of Chinese Medicine, Xian yang, China
| | - Zirun Ye
- Institute of Regenerative and Reconstructive Medicine, Med-X Institute, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- National Local Joint Engineering Research Center for Precision Surgery & Regenerative Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi Provincial Center for Regenerative Medicine and Surgical Engineering, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
| | - Zhijun Liu
- Institute of Regenerative and Reconstructive Medicine, Med-X Institute, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- National Local Joint Engineering Research Center for Precision Surgery & Regenerative Medicine, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- Shaanxi Provincial Center for Regenerative Medicine and Surgical Engineering, First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, China
- *Correspondence: Zhijun Liu,
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Canal-Alonso Á, Casado-Vara R, Castellano O, Herrera-Santos J, Gonçalves J, Màrquez-Sànchez S, Gonçalves JM, Corchado JM. An affordable implantable vagus nerve stimulator system for use in animal research. PHILOSOPHICAL TRANSACTIONS. SERIES A, MATHEMATICAL, PHYSICAL, AND ENGINEERING SCIENCES 2022; 380:20210010. [PMID: 35658680 PMCID: PMC9168444 DOI: 10.1098/rsta.2021.0010] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
In this research, a vagus nerve stimulator has been developed and miniaturized for use in epilepsy research. The board contains all the components necessary for its operation during the standard duration of the experiments, being possible to control it once implanted and even being able to reuse it. The VNS system has been designed for rodents since the VNS devices available for human are not only too large for laboratory animals, but also too expensive. With this solution the expenditure on materials made by laboratories is greatly reduced and bioethical considerations were kept in mind. The system was validated in hamsters. This article is part of the theme issue 'Advanced neurotechnologies: translating innovation for health and well-being'.
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Affiliation(s)
- Ángel Canal-Alonso
- Bioinformatics, Intelligent Systems and Educational Technology (BISITE) Research Group, Salamanca, Spain
- Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
| | - Roberto Casado-Vara
- Bioinformatics, Intelligent Systems and Educational Technology (BISITE) Research Group, Salamanca, Spain
| | - Orlando Castellano
- Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Department of Cell Biology and Pathology, Faculty of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Jorge Herrera-Santos
- Bioinformatics, Intelligent Systems and Educational Technology (BISITE) Research Group, Salamanca, Spain
| | - Jaime Gonçalves
- Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Department of Cell Biology and Pathology, Faculty of Medicine, University of Salamanca, Salamanca, Spain
- Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
| | - Sergio Màrquez-Sànchez
- Bioinformatics, Intelligent Systems and Educational Technology (BISITE) Research Group, Salamanca, Spain
| | - Jesús María Gonçalves
- Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
- Institute of Neuroscience of Castilla y León (INCYL), University of Salamanca, Salamanca, Spain
- Department of Surgery, Faculty of Medicine, University of Salamanca, Salamanca, Spain
| | - Juan Manuel Corchado
- Bioinformatics, Intelligent Systems and Educational Technology (BISITE) Research Group, Salamanca, Spain
- Institute for Biomedical Research of Salamanca (IBSAL), Salamanca, Spain
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Abstract
Mounting evidence indicates that microglia, which are the resident immune cells of the brain, play critical roles in a diverse array of neurodevelopmental processes required for proper brain maturation and function. This evidence has ultimately led to growing speculation that microglial dysfunction may play a role in neurodevelopmental disorder (NDD) pathoetiology. In this review, we first provide an overview of how microglia mechanistically contribute to the sculpting of the developing brain and neuronal circuits. To provide an example of how disruption of microglial biology impacts NDD development, we also highlight emerging evidence that has linked microglial dysregulation to autism spectrum disorder pathogenesis. In recent years, there has been increasing interest in how the gut microbiome shapes microglial biology. In the last section of this review, we put a spotlight on this burgeoning area of microglial research and discuss how microbiota-dependent modulation of microglial biology is currently thought to influence NDD progression.
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Affiliation(s)
- John R Lukens
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, Virginia, USA;
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, Virginia, USA
| | - Ukpong B Eyo
- Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, Virginia, USA;
- Center for Brain Immunology and Glia, University of Virginia, Charlottesville, Virginia, USA
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20
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Bostick JW, Schonhoff AM, Mazmanian SK. Gut microbiome-mediated regulation of neuroinflammation. Curr Opin Immunol 2022; 76:102177. [DOI: 10.1016/j.coi.2022.102177] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/07/2022] [Accepted: 03/10/2022] [Indexed: 12/12/2022]
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21
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Yu Y, Jiang X, Fang X, Wang Y, Liu P, Ling J, Yu L, Jiang M, Tang C. Transauricular Vagal Nerve Stimulation at 40 Hz Inhibits Hippocampal P2X7R/NLRP3/Caspase-1 Signaling and Improves Spatial Learning and Memory in 6-Month-Old APP/PS1 Mice. Neuromodulation 2022; 26:589-600. [PMID: 35595603 DOI: 10.1016/j.neurom.2022.03.011] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2021] [Revised: 02/04/2022] [Accepted: 03/14/2022] [Indexed: 01/01/2023]
Abstract
OBJECTIVES Transauricular vagal nerve stimulation (taVNS) at 40 Hz attenuates hippocampal amyloid load in 6-month-old amyloid precursor protein/presenilin 1 (APP/PS1) transgenic mice, but it is unclear whether 40-Hz taVNS can improve cognition in these mice. Moreover, the underlying mechanisms are still unclear. MATERIALS AND METHODS 6-month-old C57BL/6 (wild type [WT]) and APP/PS1 mice were subjected to 40-Hz taVNS. Novel Object Recognition and the Morris Water Maze were used to evaluate cognition. Hippocampal amyloid-β (Aβ)1-40, Aβ1-42, pro-interleukin (IL)-1β, and pro-IL-18 were measured using enzyme-linked immunosorbent assays. Hippocampal Aβ42, purinergic 2X7 receptor (P2X7R), nucleotide-binding oligomerization domain-like receptor pyrin domain containing 3 (NLRP3), Caspase-1, IL-1β, and IL-18 expression were evaluated by western blotting. Histologic assessments including immunofluorescence, immunohistochemistry, Nissl staining, and Congo red staining were used to assess microglial phagocytosis, neuroprotective effects, and Aβ plaque load. RESULTS 40-Hz taVNS improved spatial memory and learning in 6-month-old APP/PS1 mice but did not affect recognition memory. There were no effects on the cognitive behaviors of 6-month-old WT mice. taVNS at 40 Hz modulated microglia; significantly decreased levels of Aβ1-40, Aβ1-42, pro-IL-1β, and pro-IL-18; inhibited Aβ42, P2X7R, NLRP3, Caspase-1, IL-1β, and IL-18 expression; reduced Aβ deposits; and had neuroprotective effects in the hippocampus of 6-month-old APP/PS1 mice. These changes were not observed in 6-month-old WT mice. CONCLUSION Our results show that 40-Hz taVNS inhibits the hippocampal P2X7R/NLRP3/Caspase-1 signaling and improves spatial learning and memory in 6-month-old APP/PS1 mice.
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Affiliation(s)
- Yutian Yu
- Acupuncture Department, Beijing Shijitan Hospital, Capital Medical University, Beijing, China; Ninth School of Clinical Medicine, Peking University, Beijing, China.
| | - Xuejiao Jiang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Xian Fang
- School of Traditional Chinese Medicine, Capital Medical University, Beijing, China
| | - Yu Wang
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Science, Beijing, China
| | - Pengfei Liu
- Ninth School of Clinical Medicine, Peking University, Beijing, China; Department of Anesthesiology, Beijing Shijitan Hospital, Capital Medical University, Beijing, China
| | - Jing Ling
- Department of Gynecology, Shenzhen Traditional Chinese Medicine Hospital, Shenzhen, China
| | - Lingling Yu
- Department of Chinese and Western Medicine, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Min Jiang
- Acupuncture Department, Beijing Shijitan Hospital, Capital Medical University, Beijing, China; Ninth School of Clinical Medicine, Peking University, Beijing, China.
| | - Chunzhi Tang
- Clinical Medical College of Acupuncture, Moxibustion, and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China.
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22
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Tian Y, Gao G, Dai J. Severe tauopathy and axonopathy in the medulla oblongata in Alzheimer's disease implicate the changes in autonomic nervous function. J Chem Neuroanat 2022; 123:102105. [PMID: 35568249 DOI: 10.1016/j.jchemneu.2022.102105] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2022] [Revised: 05/06/2022] [Accepted: 05/07/2022] [Indexed: 11/17/2022]
Abstract
The autonomic dysfunctions in Alzheimer's disease (AD) have been identified from many clinical studies, however, there is still a lack of evidence directly verifying the structural abnormalities of the autonomic nervous system in AD. Human medulla oblongatas from four AD patients or five non-AD subjects were obtained and observed by using immunohistochemical staining of hyperphosphorylated tau and Aβ amyloid, and post-mortem tracing techniques. We found distinct axonal and somatic immunoreactivities for the tau markers AT8 and Tau-5 in the different areas of the medulla oblongata in AD patients, which was particularly obvious in the dorsal nucleus of the vagus nerve, the nucleus of the solitary tract and the reticular nucleus. The swollen axons, which are a typical feature of axonopathy, were not only identified in the axons with immunohistochemical labeling of AT8 and Tau-5 in the different nuclei of the medulla oblongata, but also in the tracer-labeled afferent and efferent fibres of the vagus nerve in AD patients. Such changes in tauopathy and axonopathy were only occasionally found in the non-AD aged subjects. Interestingly, we did not observe any intra- or extracellular Aβ deposits in the medulla oblongatas of the AD patients or of the non-AD subjects. These results in small samples suggest that occurrence of tauopathy and axonopathy in the parasympathetic nuclei of the medulla oblongata in AD patients may implicate the change of autonomic nervous function.
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Affiliation(s)
- Yi Tian
- Wuhan Institute for Neuroscience and Neuroengineering, South-Central Minzu University, Wuhan, Hubei, China; The College of Life Sciences, South-Central Minzu University, Wuhan, Hubei, China
| | - Ge Gao
- Tongji University School of Medicine, Shanghai, China
| | - Jiapei Dai
- Wuhan Institute for Neuroscience and Neuroengineering, South-Central Minzu University, Wuhan, Hubei, China; The College of Life Sciences, South-Central Minzu University, Wuhan, Hubei, China.
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23
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Zhou R, Qian S, Cho WCS, Zhou J, Jin C, Zhong Y, Wang J, Zhang X, Xu Z, Tian M, Chan LWC, Zhang H. Microbiota-microglia connections in age-related cognition decline. Aging Cell 2022; 21:e13599. [PMID: 35349746 PMCID: PMC9124309 DOI: 10.1111/acel.13599] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2022] [Revised: 03/08/2022] [Accepted: 03/13/2022] [Indexed: 12/13/2022] Open
Abstract
Aging is an inevitable process that all individuals experience, of which the extent differs among individuals. It has been recognized as the risk factor of neurodegenerative diseases by affecting gut microbiota compositions, microglia, and cognition abilities. Aging‐induced changes in gut microbiota compositions have a critical role in orchestrating the morphology and functions of microglia through the gut‐brain axis. Gut microbiota communicates with microglia by its secreted metabolites and neurotransmitters. This is highly associated with age‐related cognitive declines. Here, we review the main composition of microbiota in the aged individuals, outline the changes of the brain in age‐related cognitive decline from a neuroinflammation perspective, especially the changes of morphology and functions of microglia, discuss the crosstalk between microbiota and microglia in the aged brain and further highlight the role of microbiota‐microglia connections in neurodegenerative diseases (Alzheimer's disease and Parkinson's disease).
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Affiliation(s)
- Rui Zhou
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Shufang Qian
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - William C. S. Cho
- Department of Clinical Oncology Queen Elizabeth Hospital Hong Kong SAR China
| | - Jinyun Zhou
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Chentao Jin
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Yan Zhong
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Jing Wang
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Xiaohui Zhang
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Zhoujiao Xu
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Mei Tian
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
| | - Lawrence W. C. Chan
- Department of Health Technology and Informatics The Hong Kong Polytechnic University Hong Kong SAR China
| | - Hong Zhang
- Department of Nuclear Medicine and Medical PET Center The Second Affiliated Hospital of Zhejiang University School of Medicine Hangzhou China
- Key Laboratory for Biomedical Engineering of Ministry of Education Zhejiang University Hangzhou China
- The College of Biomedical Engineering and Instrument Science of Zhejiang University Hangzhou China
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24
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Effects of Long-Term Vagus Nerve Electrical Stimulation Therapy on Acute Cerebral Infarction and Neurological Function Recovery in Post MCAO Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2022; 2022:8131391. [PMID: 35391930 PMCID: PMC8983242 DOI: 10.1155/2022/8131391] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/24/2021] [Revised: 02/28/2022] [Accepted: 03/08/2022] [Indexed: 12/28/2022]
Abstract
Background Vagus nerve stimulation therapy is proven to produce neuroprotective effects against central nervous system diseases and reduce neurological injury, having a positive effect on the recovery of neurological functions in mouse model of stroke. Objective This study was aimed at exploring a wider time window for VNS treatment, investigating the long-term behavioral improvement of long-term VNS in mice after pMCAO, and exploring the antiapoptotic properties of VNS and its role in autophagy, all of which may be a permanent deficiency potential mechanism of neuroprotection in hemorrhagic stroke. Methods Permanent focal cerebral ischemia and implantation of vagus nerve stimulator were performed through intracavitary occlusion of the right middle cerebral artery (MCA). The vagus nerve stimulation group received five times vagus nerve stimulation from 6 h after surgery for 5 days. Adhesive removal test and NSS neurological score were used to evaluate the neurological deficit of mice. TTC staining of mouse brain tissue was performed one week after surgery in order to assess the area of cerebral infarction. Additionally, frozen sections were stained with Fluoro-Jade B to observe the apoptotic cells in the ischemic penumbra of brain tissue. Finally, Western blot was used to detect the changes in the levels of apoptosis-related proteins such as cleaved-caspase3 and Bcl-2 and autophagy-related proteins such as mTOR, Beclin-1, and LC3-II in brain tissue. Results VNS can effectively reduce the behavioral score of pMCAO mice; TTC results showed that VNS could effectively reduce the infarct area after pMCAO (P < 0.05). After VNS intervention of the pMCAO group compared with the pMCAO+VNI group, the FJB-positive cells in the VNS group were significantly decreased (P < 0.05); Western Blot analysis showed that the expression of cleaved-caspase3 in the brain tissue of mice increased after pMCAO (P < 0.05), and the expression of Bcl-2 decreased (P < 0.05). This change could be effectively reversed after VNS intervention (P < 0.05). Conclusion VNS could effectively improve the behavioral performance of mice after permanent stroke in addition to significantly reducing the infarct size of the brain tissue. The mechanism may be related to the effective reduction of cell apoptosis and excessive autophagy after pMCAO by VNS.
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25
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Xie J, Van Hoecke L, Vandenbroucke RE. The Impact of Systemic Inflammation on Alzheimer's Disease Pathology. Front Immunol 2022; 12:796867. [PMID: 35069578 PMCID: PMC8770958 DOI: 10.3389/fimmu.2021.796867] [Citation(s) in RCA: 79] [Impact Index Per Article: 39.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/15/2021] [Indexed: 12/11/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating age-related neurodegenerative disorder with an alarming increasing prevalence. Except for the recently FDA-approved Aducanumab of which the therapeutic effect is not yet conclusively proven, only symptomatic medication that is effective for some AD patients is available. In order to be able to design more rational and effective treatments, our understanding of the mechanisms behind the pathogenesis and progression of AD urgently needs to be improved. Over the last years, it became increasingly clear that peripheral inflammation is one of the detrimental factors that can contribute to the disease. Here, we discuss the current understanding of how systemic and intestinal (referred to as the gut-brain axis) inflammatory processes may affect brain pathology, with a specific focus on AD. Moreover, we give a comprehensive overview of the different preclinical as well as clinical studies that link peripheral Inflammation to AD initiation and progression. Altogether, this review broadens our understanding of the mechanisms behind AD pathology and may help in the rational design of further research aiming to identify novel therapeutic targets.
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Affiliation(s)
- Junhua Xie
- VIB Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Lien Van Hoecke
- VIB Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
| | - Roosmarijn E Vandenbroucke
- VIB Center for Inflammation Research, VIB, Ghent, Belgium.,Department of Biomedical Molecular Biology, Ghent University, Ghent, Belgium
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26
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Namgung U, Kim KJ, Jo BG, Park JM. Vagus nerve stimulation modulates hippocampal inflammation caused by continuous stress in rats. J Neuroinflammation 2022; 19:33. [PMID: 35109857 PMCID: PMC8812005 DOI: 10.1186/s12974-022-02396-z] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 01/20/2022] [Indexed: 12/12/2022] Open
Abstract
Background Previous studies have shown that vagus nerve stimulation (VNS) can attenuate inflammatory responses in peripheral tissues and also improve some neurological disorders and cognitive function in the brain. However, it is not clear how VNS is involved in neuropathological processes in brain tissues. Here, we investigated the regulatory effects of VNS on the production of proinflammatory cytokines in the hippocampus of an animal model of continuous stress (CS). Methods CS was induced by placing rats in cages immersed with water, and acute or chronic electrical stimulation was applied to the cervical vagus nerve of CS animals. Protein levels in the gastric and hippocampal tissues were measured by western blotting and protein signals analyzed by immunofluorescence staining. von Frey test and forced swimming test were performed to assess pain sensitivity and depressive-like behavior in rats, respectively. Results Levels of TNF-α, IL-1β, and IL-6 in the gastric and hippocampal tissues were significantly increased in CS animals compared to the untreated control and downregulated by acute VNS (aVNS). Iba-1-labeled microglial cells in the hippocampus of CS animals revealed morphological features of activated inflammatory cells and then changed to a normal shape by VNS. VNS elevated hippocampal expression of α7 nicotinic acetylcholine receptors (α7 nAChR) in CS animals, and pharmacological blockade of α7 nAChR increased the production of TNF-α, IL-1β, and IL-6, thus suppressing cholinergic anti-inflammatory activity that was mediated by VNS. Chronic VNS (cVNS) down-regulated the hippocampal production of active form of caspase 3 and 5-HT1A receptors and also decreased levels of TNF-α, IL-1β, and IL-6 in the gastric and hippocampal tissues of CS animals. Pain sensitivity and depressive-like behavior, which were increased by CS, were improved by cVNS. Conclusions Our data suggest that VNS may be involved in modulating pathophysiological processes caused by CS in the brain.
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Affiliation(s)
- Uk Namgung
- Department of Oriental Medicine, Institute of Bioscience and Integrative Medicine, Daejeon University, Daehak-ro 62, Daejeon, 34520, South Korea.
| | - Ki-Joong Kim
- Department of Oriental Medicine, Institute of Bioscience and Integrative Medicine, Daejeon University, Daehak-ro 62, Daejeon, 34520, South Korea
| | - Byung-Gon Jo
- Department of Oriental Medicine, Institute of Bioscience and Integrative Medicine, Daejeon University, Daehak-ro 62, Daejeon, 34520, South Korea
| | - Jong Min Park
- Department of Oriental Medicine, Institute of Bioscience and Integrative Medicine, Daejeon University, Daehak-ro 62, Daejeon, 34520, South Korea
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27
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Tynan A, Brines M, Chavan SS. Control of inflammation using non-invasive neuromodulation: past, present and promise. Int Immunol 2022; 34:119-128. [PMID: 34558623 PMCID: PMC8783606 DOI: 10.1093/intimm/dxab073] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Accepted: 09/20/2021] [Indexed: 12/14/2022] Open
Abstract
The nervous system has been increasingly recognized as a novel and accessible target in the regulation of inflammation. The use of implantable and invasive devices targeting neural circuits has yielded successful results in clinical settings but does have some risk or adverse effects. Recent advances in technology and understanding of mechanistic pathways have opened new avenues of non-invasive neuromodulation. Through this review we discuss the novel research and outcomes of major modalities of non-invasive neuromodulation in the context of inflammation including transcutaneous electrical, magnetic and ultrasound neuromodulation. In addition to highlighting the scientific observations and breakthroughs, we discuss the underlying mechanisms and pathways for neural regulation of inflammation.
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Affiliation(s)
- Aisling Tynan
- Laboratory of Biomedical Science, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, Manhasset, NY, USA
| | - Michael Brines
- Laboratory of Biomedical Science, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, Manhasset, NY, USA
| | - Sangeeta S Chavan
- Laboratory of Biomedical Science, Institute of Bioelectronic Medicine, Feinstein Institutes for Medical Research, Northwell Health, 350 Community Drive, Manhasset, NY, USA
- Elmezzi Graduate School of Molecular Medicine, 350 Community Drive, Manhasset, NY, USA
- Donald and Barbara Zucker School of Medicine at Hofstra University, Hempstead, NY, USA
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28
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Krey L, Huber MK, Höglinger GU, Wegner F. Can SARS-CoV-2 Infection Lead to Neurodegeneration and Parkinson's Disease? Brain Sci 2021; 11:1654. [PMID: 34942956 PMCID: PMC8699589 DOI: 10.3390/brainsci11121654] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 12/08/2021] [Accepted: 12/16/2021] [Indexed: 12/12/2022] Open
Abstract
The SARS-CoV-2 pandemic has affected the daily life of the worldwide population since 2020. Links between the newly discovered viral infection and the pathogenesis of neurodegenerative diseases have been investigated in different studies. This review aims to summarize the literature concerning COVID-19 and Parkinson's disease (PD) to give an overview on the interface between viral infection and neurodegeneration with regard to this current topic. We will highlight SARS-CoV-2 neurotropism, neuropathology and the suspected pathophysiological links between the infection and neurodegeneration as well as the psychosocial impact of the pandemic on patients with PD. Some evidence discussed in this review suggests that the SARS-CoV-2 pandemic might be followed by a higher incidence of neurodegenerative diseases in the future. However, the data generated so far are not sufficient to confirm that COVID-19 can trigger or accelerate neurodegenerative diseases.
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Affiliation(s)
- Lea Krey
- Department of Neurology, Hannover Medical School, Carl-Neuberg-Straße 1, 30625 Hannover, Germany; (M.K.H.); (G.U.H.); (F.W.)
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29
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Ramos-Martínez IE, Rodríguez MC, Cerbón M, Ramos-Martínez JC, Ramos-Martínez EG. Role of the Cholinergic Anti-Inflammatory Reflex in Central Nervous System Diseases. Int J Mol Sci 2021; 22:ijms222413427. [PMID: 34948222 PMCID: PMC8705572 DOI: 10.3390/ijms222413427] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2021] [Revised: 11/30/2021] [Accepted: 12/07/2021] [Indexed: 12/12/2022] Open
Abstract
In several central nervous system diseases, it has been reported that inflammation may be related to the etiologic process, therefore, therapeutic strategies are being implemented to control inflammation. As the nervous system and the immune system maintain close bidirectional communication in physiological and pathological conditions, the modulation of inflammation through the cholinergic anti-inflammatory reflex has been proposed. In this review, we summarized the evidence supporting chemical stimulation with cholinergic agonists and vagus nerve stimulation as therapeutic strategies in the treatment of various central nervous system pathologies, and their effect on inflammation.
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Affiliation(s)
- Ivan Emmanuel Ramos-Martínez
- Glycobiology, Cell Growth and Tissue Repair Research Unit (Gly-CRRET), Université Paris Est Créteil (UPEC), 94010 Créteil, France;
| | - María Carmen Rodríguez
- Centro de Investigación Sobre Enfermedades Infecciosas, Instituto Nacional de Salud Pública, SSA, Morelos 62100, Mexico;
| | - Marco Cerbón
- Unidad de Investigación en Reproducción Humana, Instituto Nacional de Perinatología-Facultad de Química, Universidad Nacional Autónoma de México, Ciudad de México 04510, Mexico
- Correspondence: (M.C.); (E.G.R.-M.)
| | - Juan Carlos Ramos-Martínez
- Cardiology Department, Hospital General Regional Lic. Ignacio Garcia Tellez IMSS, Yucatán 97150, Mexico;
| | - Edgar Gustavo Ramos-Martínez
- Escuela de Ciencias, Universidad Autónoma Benito Juárez de Oaxaca, Oaxaca 68120, Mexico
- Instituto de Cómputo Aplicado en Ciencias, Oaxaca 68044, Mexico
- Correspondence: (M.C.); (E.G.R.-M.)
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30
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Jeong WH, Kim WI, Lee JW, Park HK, Song MK, Choi IS, Han JY. Modulation of Long-Term Potentiation by Gamma Frequency Transcranial Alternating Current Stimulation in Transgenic Mouse Models of Alzheimer's Disease. Brain Sci 2021; 11:1532. [PMID: 34827531 PMCID: PMC8615498 DOI: 10.3390/brainsci11111532] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 11/17/2021] [Accepted: 11/17/2021] [Indexed: 11/16/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) is a neuromodulation procedure that is currently studied for the purpose of improving cognitive function in various diseases. A few studies have shown positive effects of tACS in Alzheimer's disease (AD). However, the mechanism underlying tACS has not been established. The purpose of this study was to investigate the mechanism of tACS in five familial AD mutation (5xFAD) mouse models. We prepared twenty 4-month-old mice and divided them into four groups: wild-type mice without stimulation (WT-NT group), wild-type mice with tACS (WT-T group), 5xFAD mice without stimulation (AD-NT group), and 5xFAD mice with tACS (AD-T group). The protocol implemented was as follows: gamma frequency 200 μA over the bilateral frontal lobe for 20 min over 2 weeks. The following tests were conducted: excitatory postsynaptic potential (EPSP) recording, Western blot analysis (cyclic AMP response element-binding (CREB) proteins, phosphorylated CREB proteins, brain-derived neurotrophic factor, and parvalbumin) to examine the synaptic plasticity. The EPSP was remarkably increased in the AD-T group compared with in the AD-NT group. In the Western blot analysis, the differences among the groups were not significant. Hence, tACS can affect the long-lasting enhancement of synaptic transmission in mice models of AD.
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Affiliation(s)
- Won-Hyeong Jeong
- Department of Physical & Rehabilitation Medicine, Chonnam National University Hospital, Gwangju City 61469, Korea; (W.-H.J.); (W.-I.K.); (J.-W.L.); (H.-K.P.); (I.-S.C.)
| | - Wang-In Kim
- Department of Physical & Rehabilitation Medicine, Chonnam National University Hospital, Gwangju City 61469, Korea; (W.-H.J.); (W.-I.K.); (J.-W.L.); (H.-K.P.); (I.-S.C.)
| | - Jin-Won Lee
- Department of Physical & Rehabilitation Medicine, Chonnam National University Hospital, Gwangju City 61469, Korea; (W.-H.J.); (W.-I.K.); (J.-W.L.); (H.-K.P.); (I.-S.C.)
| | - Hyeng-Kyu Park
- Department of Physical & Rehabilitation Medicine, Chonnam National University Hospital, Gwangju City 61469, Korea; (W.-H.J.); (W.-I.K.); (J.-W.L.); (H.-K.P.); (I.-S.C.)
| | - Min-Keun Song
- Department of Physical & Rehabilitation Medicine, Regional Cardiocerebrovascular Center, Center for Aging and Geriatrics, Chonnam National University Medical School & Hospital, Gwangju City 61469, Korea;
| | - In-Sung Choi
- Department of Physical & Rehabilitation Medicine, Chonnam National University Hospital, Gwangju City 61469, Korea; (W.-H.J.); (W.-I.K.); (J.-W.L.); (H.-K.P.); (I.-S.C.)
| | - Jae-Young Han
- Department of Physical & Rehabilitation Medicine, Regional Cardiocerebrovascular Center, Center for Aging and Geriatrics, Chonnam National University Medical School & Hospital, Gwangju City 61469, Korea;
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31
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Frausto DM, Forsyth CB, Keshavarzian A, Voigt RM. Dietary Regulation of Gut-Brain Axis in Alzheimer's Disease: Importance of Microbiota Metabolites. Front Neurosci 2021; 15:736814. [PMID: 34867153 PMCID: PMC8639879 DOI: 10.3389/fnins.2021.736814] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that impacts 45 million people worldwide and is ranked as the 6th top cause of death among all adults by the Centers for Disease Control and Prevention. While genetics is an important risk factor for the development of AD, environment and lifestyle are also contributing risk factors. One such environmental factor is diet, which has emerged as a key influencer of AD development/progression as well as cognition. Diets containing large quantities of saturated/trans-fats, refined carbohydrates, limited intake of fiber, and alcohol are associated with cognitive dysfunction while conversely diets low in saturated/trans-fats (i.e., bad fats), high mono/polyunsaturated fats (i.e., good fats), high in fiber and polyphenols are associated with better cognitive function and memory in both humans and animal models. Mechanistically, this could be the direct consequence of dietary components (lipids, vitamins, polyphenols) on the brain, but other mechanisms are also likely to be important. Diet is considered to be the single greatest factor influencing the intestinal microbiome. Diet robustly influences the types and function of micro-organisms (called microbiota) that reside in the gastrointestinal tract. Availability of different types of nutrients (from the diet) will favor or disfavor the abundance and function of certain groups of microbiota. Microbiota are highly metabolically active and produce many metabolites and other factors that can affect the brain including cognition and the development and clinical progression of AD. This review summarizes data to support a model in which microbiota metabolites influence brain function and AD.
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Affiliation(s)
- Dulce M. Frausto
- Rush Medical College, Rush Center for Integrated Microbiome and Chronobiology Research, Rush University Medical Center, Chicago, IL, United States
| | - Christopher B. Forsyth
- Rush Medical College, Rush Center for Integrated Microbiome and Chronobiology Research, Rush University Medical Center, Chicago, IL, United States
- Department of Medicine, Rush University Medical Center, Chicago, IL, United States
| | - Ali Keshavarzian
- Rush Medical College, Rush Center for Integrated Microbiome and Chronobiology Research, Rush University Medical Center, Chicago, IL, United States
- Department of Medicine, Rush University Medical Center, Chicago, IL, United States
- Department of Physiology, Rush University Medical Center, Chicago, IL, United States
| | - Robin M. Voigt
- Rush Medical College, Rush Center for Integrated Microbiome and Chronobiology Research, Rush University Medical Center, Chicago, IL, United States
- Department of Medicine, Rush University Medical Center, Chicago, IL, United States
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32
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de Gurtubay IG, Bermejo P, Lopez M, Larraya I, Librero J. Evaluation of different vagus nerve stimulation anatomical targets in the ear by vagus evoked potential responses. Brain Behav 2021; 11:e2343. [PMID: 34551214 PMCID: PMC8613407 DOI: 10.1002/brb3.2343] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2021] [Revised: 07/05/2021] [Accepted: 08/09/2021] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND Electrical auricular vagus nerve stimulation (taVNS) is an emerging therapy. Stimuli are transported to brainstem nuclei, whereby its multiple projections reach to many subcortical and cortical areas, thus allowing the neuromodulation of several systemic physiological processes. We aim to define the best auricular target for taVNS through vagus somatosensory evoked potential (VSEP) elicited stimulating different auricular areas with different electrode sizes. METHODS Twenty-six subjects were enrolled. Three stimulation areas were studied: simultaneous cymba and cavum (CC), cymba (C) and earlobe (L); and two electrode sizes: extra-large (X) and small (S). We studied the effect of five combinations (CCX, CCS, CS, LX and LS) on VSEP´s latency and amplitude, and sensory and pain threshold (Pt) using a lineal mixed model regression analysis. We used CS combination, used in a commercial device, as reference model. RESULTS Valid VSEP were obtained for CCX, CCS and CS but not in LX and LS. Both CCS and CCX tests showed significant amplitude increases. The same effect was observed in CCX using CCS as reference. Significant increases in Pt were found for CCX and LX. The same effect was observed in CCX using LX as reference. CONCLUSION The results suggest that CC and C areas are active targets for taVNS but not for earlobe, as anatomical data support. Considering that amplitude reflects the synchronized electrical activity generated, we conclude the most effective topography is the simultaneous stimulation of cymba and concha. The use of X-sized electrodes increases the amplitudes and makes the stimulation more comfortable.
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Affiliation(s)
| | - Pedro Bermejo
- Department of Neurology, Puerta de Hierro Hospital, Madrid, Spain.,Walden Medical Neurodigital Therapies, Gijón, Spain
| | - Miguel Lopez
- Walden Medical Neurodigital Therapies, Gijón, Spain
| | | | - Julian Librero
- Biomedical Research Centre of the Government of Navarre, Pamplona, Spain
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Parodi B, Kerlero de Rosbo N. The Gut-Brain Axis in Multiple Sclerosis. Is Its Dysfunction a Pathological Trigger or a Consequence of the Disease? Front Immunol 2021; 12:718220. [PMID: 34621267 PMCID: PMC8490747 DOI: 10.3389/fimmu.2021.718220] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 09/07/2021] [Indexed: 12/12/2022] Open
Abstract
A large and expending body of evidence indicates that the gut-brain axis likely plays a crucial role in neurological diseases, including multiple sclerosis (MS). As a whole, the gut-brain axis can be considered as a bi-directional multi-crosstalk pathway that governs the interaction between the gut microbiota and the organism. Perturbation in the commensal microbial population, referred to as dysbiosis, is frequently associated with an increased intestinal permeability, or "leaky gut", which allows the entrance of exogeneous molecules, in particular bacterial products and metabolites, that can disrupt tissue homeostasis and induce inflammation, promoting both local and systemic immune responses. An altered gut microbiota could therefore have significant repercussions not only on immune responses in the gut but also in distal effector immune sites such as the CNS. Indeed, the dysregulation of this bi-directional communication as a consequence of dysbiosis has been implicated as playing a possible role in the pathogenesis of neurological diseases. In multiple sclerosis (MS), the gut-brain axis is increasingly being considered as playing a crucial role in its pathogenesis, with a major focus on specific gut microbiota alterations associated with the disease. In both MS and its purported murine model, experimental autoimmune encephalomyelitis (EAE), gastrointestinal symptoms and/or an altered gut microbiota have been reported together with increased intestinal permeability. In both EAE and MS, specific components of the microbiota have been shown to modulate both effector and regulatory T-cell responses and therefore disease progression, and EAE experiments with germ-free and specific pathogen-free mice transferred with microbiota associated or not with disease have clearly demonstrated the possible role of the microbiota in disease pathogenesis and/or progression. Here, we review the evidence that can point to two possible consequences of the gut-brain axis dysfunction in MS and EAE: 1. A pro-inflammatory intestinal environment and "leaky" gut induced by dysbiosis could lead to an altered communication with the CNS through the cholinergic afferent fibers, thereby contributing to CNS inflammation and disease pathogenesis; and 2. Neuroinflammation affecting efferent cholinergic transmission could result in intestinal inflammation as disease progresses.
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Affiliation(s)
- Benedetta Parodi
- Department of Neurosciences, Rehabilitation, Ophthalmology and Maternal-Fetal Medicine (DINOGMI), University of Genoa, Genoa, Italy
| | - Nicole Kerlero de Rosbo
- Department of Neurosciences, Rehabilitation, Ophthalmology and Maternal-Fetal Medicine (DINOGMI), University of Genoa, Genoa, Italy.,TomaLab, Institute of Nanotechnology, Consiglio Nazionale delle Ricerche (CNR), Rome, Italy
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34
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Keute M, Gharabaghi A. Brain plasticity and vagus nerve stimulation. Auton Neurosci 2021; 236:102876. [PMID: 34537681 DOI: 10.1016/j.autneu.2021.102876] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2021] [Revised: 07/01/2021] [Accepted: 08/29/2021] [Indexed: 01/01/2023]
Abstract
After damage to the central nervous system, caused by traumatic injury or ischemia, plasticity becomes critically important for functional recovery. When this inherent capacity to adapt is limited despite training, external stimulation may support this process. Vagus nerve stimulation (VNS) is an effective method to enhance the effect of motor rehabilitation training on functional recovery. However, the mechanisms by which VNS exerts beneficial effects on cortical plasticity are not completely understood. Experimental work suggests that VNS fosters a neurochemical milieu that facilitates synaptic plasticity and supports reinforcement mechanisms. Animal studies, furthermore, suggest that VNS delivery is time-critical and that optima in the parameter space need to be titrated for effect maximization. Human studies suggest that VNS modifies corticospinal excitability. First studies in stroke patients show positive results for invasive, and also promising findings for non-invasive VNS.
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Affiliation(s)
- Marius Keute
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University of Tuebingen, Tuebingen, Germany.
| | - Alireza Gharabaghi
- Institute for Neuromodulation and Neurotechnology, Department of Neurosurgery and Neurotechnology, University of Tuebingen, Tuebingen, Germany
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35
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Loss of vagal integrity disrupts immune components of the microbiota-gut-brain axis and inhibits the effect of Lactobacillus rhamnosus on behavior and the corticosterone stress response. Neuropharmacology 2021; 195:108682. [PMID: 34175326 DOI: 10.1016/j.neuropharm.2021.108682] [Citation(s) in RCA: 36] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/01/2021] [Accepted: 06/15/2021] [Indexed: 01/09/2023]
Abstract
The vagus nerve is one of the major signalling components between the gut microbiota and brain. However, the exact relationship between gut-brain signaling along the vagus and the effects of gut microbes on brain function and behaviour is unclear. In particular, the relationship between the vagus nerve and immune signaling, that also appears to play a critical role in microbiota-gut-brain communication, has not been delineated. The aim of the present study was to determine the effect of subdiaphragmatic vagotomy on peripheral and central immune changes associated with the anxiolytic actions of L.rhamnosus. Male mice underwent vagotomy or sham surgery, followed by administration of L.rhamnosus for 14 days. L.rhamnosus administration following sham surgery resulted in reduced anxiety-like behaviour, and an attenuation of the hypothalamic-pituitary-adrenal axis (HPA axis), as indicated by reduced plasma corticosterone after acute restraint stress. These effects were associated with an increase in splenic T regulatory cells and a decrease in activated microglia in the hippocampus. The anxiolytic effects, HPA modulation and increase in T regulatory cells were prevented by vagotomy, whereas vagotomy alone led to a significant increase in activated microglia in the hippocampus that was not altered with L.rhamnosus treatment. Thus, both microbe induced and constitutive vagal signaling influences critical immune components of the microbiota-gut-brain axis. These findings suggest that, rather than acting as a direct neural link to the central nervous system, the role of the vagus nerve in gut-microbe to brain signalling is as an integral component of a bi-directional neuroimmunoendocrine pathway.
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36
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Alexaki VI. The Impact of Obesity on Microglial Function: Immune, Metabolic and Endocrine Perspectives. Cells 2021; 10:cells10071584. [PMID: 34201844 PMCID: PMC8307603 DOI: 10.3390/cells10071584] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2021] [Revised: 06/18/2021] [Accepted: 06/22/2021] [Indexed: 02/06/2023] Open
Abstract
Increased life expectancy in combination with modern life style and high prevalence of obesity are important risk factors for development of neurodegenerative diseases. Neuroinflammation is a feature of neurodegenerative diseases, and microglia, the innate immune cells of the brain, are central players in it. The present review discusses the effects of obesity, chronic peripheral inflammation and obesity-associated metabolic and endocrine perturbations, including insulin resistance, dyslipidemia and increased glucocorticoid levels, on microglial function.
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Affiliation(s)
- Vasileia Ismini Alexaki
- Institute for Clinical Chemistry and Laboratory Medicine, University Clinic Carl Gustav Carus, TU Dresden, Fetscherstrasse 74, 01307 Dresden, Germany
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37
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Ruhnau P, Zaehle T. Transcranial Auricular Vagus Nerve Stimulation (taVNS) and Ear-EEG: Potential for Closed-Loop Portable Non-invasive Brain Stimulation. Front Hum Neurosci 2021; 15:699473. [PMID: 34194308 PMCID: PMC8236702 DOI: 10.3389/fnhum.2021.699473] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 05/21/2021] [Indexed: 11/17/2022] Open
Abstract
No matter how hard we concentrate, our attention fluctuates – a fact that greatly affects our success in completing a current task. Here, we review work from two methods that, in a closed-loop manner, have the potential to ameliorate these fluctuations. Ear-EEG can measure electric brain activity from areas in or around the ear, using small and thus portable hardware. It has been shown to capture the state of attention with high temporal resolution. Transcutaneous auricular vagus nerve stimulation (taVNS) comes with the same advantages (small and light) and critically current research suggests that it is possible to influence ongoing brain activity that has been linked to attention. Following the review of current work on ear-EEG and taVNS we suggest that a combination of the two methods in a closed-loop system could serve as a potential application to modulate attention.
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Affiliation(s)
- Philipp Ruhnau
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto von Guericke University, Magdeburg, Germany
| | - Tino Zaehle
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany.,Center for Behavioral Brain Sciences, Otto von Guericke University, Magdeburg, Germany
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38
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Transcutaneous vagus nerve stimulation in patients with attention-deficit/hyperactivity disorder: A viable option? PROGRESS IN BRAIN RESEARCH 2021; 264:171-190. [PMID: 34167655 DOI: 10.1016/bs.pbr.2021.03.001] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Individuals with attention-deficit/hyperactivity disorder (ADHD) suffer from a range of cognitive and behavioral problems that severely impair their educational and occupational attainment. ADHD symptoms have been linked to structural and functional changes within and between different brain regions, particularly the prefrontal cortex. At the system level, reduced availability of the neurotransmitters dopamine (DA) and norepinephrine (NE) but also γ-aminobutyric acid (GABA) have been repeatedly demonstrated. Recently, non-invasive brain stimulation (NIBS) techniques have been explored as treatment alternatives to alter dysfunctional activation patterns in specified brain areas or networks. In the current paper, we introduce transcutaneous vagus nerve stimulation (tVNS) as a systemic approach to directly affect NE and GABA neurotransmission. TVNS is a non-drug intervention with low risk and proven efficacy in improving cognitive particularly executive functions. It is easy to apply and therefore well-suited to provide home-based or mobile treatment options allowing a significant increase in treatment intensity and providing easier access to medical care for individuals who are unable to regularly visit a clinician. We describe in detail the underlying mechanisms of tVNS and current fields of application and discuss its potential as an adjuvant treatment for ADHD.
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39
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Keute M, Wienke C, Ruhnau P, Zaehle T. Effects of transcutaneous vagus nerve stimulation (tVNS) on beta and gamma brain oscillations. Cortex 2021; 140:222-231. [PMID: 34015727 DOI: 10.1016/j.cortex.2021.04.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Revised: 04/05/2021] [Accepted: 04/12/2021] [Indexed: 12/01/2022]
Abstract
Physiological and behavioral effects induced through transcutaneous vagus nerve stimulation (tVNS) are under scrutiny in a growing number of studies, yet its mechanisms of action remain poorly understood. One candidate mechanism is a modulation of γ-aminobutyric acid (GABA) transmission through tVNS. Two recent behavioral studies suggest that such a GABAergic effect might occur in a lateralized fashion, i.e., the GABA modulation might be stronger in the left than in the right brain hemisphere after tVNS applied to the left ear. Using magnetoencephalography (MEG), we tested for GABA-associated modulations in resting and event-related brain oscillations and for a lateralization of those effects in a sample of 41 healthy young adults. Our data provide substantial evidence against all hypotheses, i.e., we neither find effects of tVNS on oscillatory power nor a lateralization of effects.
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Affiliation(s)
- Marius Keute
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Institute for Neuromodulation and Neurotechnology, University of Tübingen, Tübingen, Germany.
| | - Christian Wienke
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg
| | - Philipp Ruhnau
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg
| | - Tino Zaehle
- Department of Neurology, Otto-von Guericke-University, Magdeburg, Germany; Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg
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40
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Slater C, Wang Q. Alzheimer's disease: An evolving understanding of noradrenergic involvement and the promising future of electroceutical therapies. Clin Transl Med 2021; 11:e397. [PMID: 33931975 PMCID: PMC8087948 DOI: 10.1002/ctm2.397] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 04/05/2021] [Accepted: 04/11/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) poses a significant global health concern over the next several decades. Multiple hypotheses have been put forth that attempt to explain the underlying pathophysiology of AD. Many of these are briefly reviewed here, but to-date no disease-altering therapy has been achieved. Despite this, recent work expanding on the role of noradrenergic system dysfunction in both the pathogenesis and symptomatic exacerbation of AD has shown promise. The role norepinephrine (NE) plays in AD remains complicated but pre-tangle tau has consistently been shown to arise in the locus coeruleus (LC) of patients with AD decades before symptom onset. The current research reviewed here indicates NE can facilitate neuroprotective and memory-enhancing effects through β adrenergic receptors, while α2A adrenergic receptors may exacerbate amyloid toxicity through a contribution to tau hyperphosphorylation. AD appears to involve a disruption in the balance between these two receptors and their various subtypes. There is also a poorly characterized interplay between the noradrenergic and cholinergic systems. LC deterioration leads to maladaptation in the remaining LC-NE system and subsequently inhibits cholinergic neuron function, eventually leading to the classic cholinergic disruption seen in AD. Understanding AD as a dysfunctional noradrenergic system, provides new avenues for the use of advanced neural stimulation techniques to both study and therapeutically target the earliest stages of neuropathology. Direct LC stimulation and non-invasive vagus nerve stimulation (VNS) have both demonstrated potential use as AD therapeutics. Significant work remains, though, to better understand the role of the noradrenergic system in AD and how electroceuticals can provide disease-altering treatments.
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Affiliation(s)
- Cody Slater
- Department of Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
- Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNew YorkUSA
| | - Qi Wang
- Department of Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
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41
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Farmer AD, Strzelczyk A, Finisguerra A, Gourine AV, Gharabaghi A, Hasan A, Burger AM, Jaramillo AM, Mertens A, Majid A, Verkuil B, Badran BW, Ventura-Bort C, Gaul C, Beste C, Warren CM, Quintana DS, Hämmerer D, Freri E, Frangos E, Tobaldini E, Kaniusas E, Rosenow F, Capone F, Panetsos F, Ackland GL, Kaithwas G, O'Leary GH, Genheimer H, Jacobs HIL, Van Diest I, Schoenen J, Redgrave J, Fang J, Deuchars J, Széles JC, Thayer JF, More K, Vonck K, Steenbergen L, Vianna LC, McTeague LM, Ludwig M, Veldhuizen MG, De Couck M, Casazza M, Keute M, Bikson M, Andreatta M, D'Agostini M, Weymar M, Betts M, Prigge M, Kaess M, Roden M, Thai M, Schuster NM, Montano N, Hansen N, Kroemer NB, Rong P, Fischer R, Howland RH, Sclocco R, Sellaro R, Garcia RG, Bauer S, Gancheva S, Stavrakis S, Kampusch S, Deuchars SA, Wehner S, Laborde S, Usichenko T, Polak T, Zaehle T, Borges U, Teckentrup V, Jandackova VK, Napadow V, Koenig J. International Consensus Based Review and Recommendations for Minimum Reporting Standards in Research on Transcutaneous Vagus Nerve Stimulation (Version 2020). Front Hum Neurosci 2021; 14:568051. [PMID: 33854421 PMCID: PMC8040977 DOI: 10.3389/fnhum.2020.568051] [Citation(s) in RCA: 131] [Impact Index Per Article: 43.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 09/01/2020] [Indexed: 12/18/2022] Open
Abstract
Given its non-invasive nature, there is increasing interest in the use of transcutaneous vagus nerve stimulation (tVNS) across basic, translational and clinical research. Contemporaneously, tVNS can be achieved by stimulating either the auricular branch or the cervical bundle of the vagus nerve, referred to as transcutaneous auricular vagus nerve stimulation(VNS) and transcutaneous cervical VNS, respectively. In order to advance the field in a systematic manner, studies using these technologies need to adequately report sufficient methodological detail to enable comparison of results between studies, replication of studies, as well as enhancing study participant safety. We systematically reviewed the existing tVNS literature to evaluate current reporting practices. Based on this review, and consensus among participating authors, we propose a set of minimal reporting items to guide future tVNS studies. The suggested items address specific technical aspects of the device and stimulation parameters. We also cover general recommendations including inclusion and exclusion criteria for participants, outcome parameters and the detailed reporting of side effects. Furthermore, we review strategies used to identify the optimal stimulation parameters for a given research setting and summarize ongoing developments in animal research with potential implications for the application of tVNS in humans. Finally, we discuss the potential of tVNS in future research as well as the associated challenges across several disciplines in research and clinical practice.
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Affiliation(s)
- Adam D. Farmer
- Department of Gastroenterology, University Hospitals of North Midlands NHS Trust, Stoke on Trent, United Kingdom
| | - Adam Strzelczyk
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | | | - Alexander V. Gourine
- Department of Neuroscience, Physiology and Pharmacology, Centre for Cardiovascular and Metabolic Neuroscience, University College London, London, United Kingdom
| | - Alireza Gharabaghi
- Institute for Neuromodulation and Neurotechnology, University Hospital and University of Tuebingen, Tuebingen, Germany
| | - Alkomiet Hasan
- Department of Psychiatry, Psychotherapy and Psychosomatics, Medical Faculty, University of Augsburg, Augsburg, Germany
- Department of Psychiatry and Psychotherapy, University Hospital, LMU Munich, Munich, Germany
| | - Andreas M. Burger
- Laboratory for Biological Psychology, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
| | | | - Ann Mertens
- Department of Neurology, Institute for Neuroscience, 4Brain, Ghent University Hospital, Gent, Belgium
| | - Arshad Majid
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Bart Verkuil
- Clinical Psychology and the Leiden Institute of Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Bashar W. Badran
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Carlos Ventura-Bort
- Department of Biological Psychology and Affective Science, Faculty of Human Sciences, University of Potsdam, Potsdam, Germany
| | - Charly Gaul
- Migraine and Headache Clinic Koenigstein, Königstein im Taunus, Germany
| | - Christian Beste
- Cognitive Neurophysiology, Department of Child and Adolescent Psychiatry, Faculty of Medicine, TU Dresden, Dresden, Germany
| | | | - Daniel S. Quintana
- NORMENT, Division of Mental Health and Addiction, University of Oslo and Oslo University Hospital, Oslo, Norway
- Department of Psychology, University of Oslo, Oslo, Norway
- KG Jebsen Centre for Neurodevelopmental Disorders, University of Oslo, Oslo, Norway
| | - Dorothea Hämmerer
- Medical Faculty, Institute of Cognitive Neurology and Dementia Research, Otto-von-Guericke University, Magdeburg, Germany
- Institute of Cognitive Neuroscience, University College London, London, United Kingdom
- Center for Behavioral Brain Sciences Magdeburg (CBBS), Otto-von-Guericke University, Magdeburg, Germany
| | - Elena Freri
- Department of Pediatric Neuroscience, Fondazione IRCCS Istituto Neurologico Carlo Besta, Milan, Italy
| | - Eleni Frangos
- Pain and Integrative Neuroscience Branch, National Center for Complementary and Integrative Health, NIH, Bethesda, MD, United States
| | - Eleonora Tobaldini
- Department of Internal Medicine, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Eugenijus Kaniusas
- Institute of Electrodynamics, Microwave and Circuit Engineering, TU Wien, Vienna, Austria
- SzeleSTIM GmbH, Vienna, Austria
| | - Felix Rosenow
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Fioravante Capone
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Università Campus Bio-Medico di Roma, Rome, Italy
| | - Fivos Panetsos
- Faculty of Biology and Faculty of Optics, Complutense University of Madrid and Institute for Health Research, San Carlos Clinical Hospital (IdISSC), Madrid, Spain
| | - Gareth L. Ackland
- Translational Medicine and Therapeutics, Barts and The London School of Medicine and Dentistry, William Harvey Research Institute, Queen Mary University of London, London, United Kingdom
| | - Gaurav Kaithwas
- Department of Pharmaceutical Sciences, School of Biosciences and Biotechnology, Babasaheb Bhimrao Ambedkar University (A Central University), Lucknow, India
| | - Georgia H. O'Leary
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Hannah Genheimer
- Department of Biological Psychology, Clinical Psychology and Psychotherapy, University of Würzburg, Würzburg, Germany
| | - Heidi I. L. Jacobs
- Division of Nuclear Medicine and Molecular Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, United States
- Faculty of Health, Medicine and Life Sciences, School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, Maastricht, Netherlands
| | - Ilse Van Diest
- Research Group Health Psychology, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
| | - Jean Schoenen
- Headache Research Unit, Department of Neurology-Citadelle Hospital, University of Liège, Liège, Belgium
| | - Jessica Redgrave
- Sheffield Institute for Translational Neuroscience (SITraN), University of Sheffield, Sheffield, United Kingdom
| | - Jiliang Fang
- Functional Imaging Lab, Department of Radiology, Guang An Men Hospital, China Academy of Chinese Medical Sciences, Beijing, China
| | - Jim Deuchars
- School of Biomedical Science, Faculty of Biological Science, University of Leeds, Leeds, United Kingdom
| | - Jozsef C. Széles
- Division for Vascular Surgery, Department of Surgery, Medical University of Vienna, Vienna, Austria
| | - Julian F. Thayer
- Department of Psychological Science, University of California, Irvine, Irvine, CA, United States
| | - Kaushik More
- Institute for Cognitive Neurology and Dementia Research, Otto-von-Guericke-University Magdeburg, Magdeburg, Germany
- Neuromodulatory Networks, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Kristl Vonck
- Department of Neurology, Institute for Neuroscience, 4Brain, Ghent University Hospital, Gent, Belgium
| | - Laura Steenbergen
- Clinical and Cognitive Psychology and the Leiden Institute of Brain and Cognition, Leiden University, Leiden, Netherlands
| | - Lauro C. Vianna
- NeuroV̇ASQ̇ - Integrative Physiology Laboratory, Faculty of Physical Education, University of Brasilia, Brasilia, Brazil
| | - Lisa M. McTeague
- Department of Psychiatry, Medical University of South Carolina, Charleston, SC, United States
| | - Mareike Ludwig
- Department of Anatomy, Faculty of Medicine, Mersin University, Mersin, Turkey
| | - Maria G. Veldhuizen
- Mental Health and Wellbeing Research Group, Vrije Universiteit Brussel, Brussels, Belgium
| | - Marijke De Couck
- Faculty of Health Care, University College Odisee, Aalst, Belgium
- Division of Epileptology, Fondazione IRCCS Istituto Neurologico C. Besta, Milan, Italy
| | - Marina Casazza
- Department of Neurosurgery, University of Tübingen, Tübingen, Germany
| | - Marius Keute
- Institute for Neuromodulation and Neurotechnology, University Hospital and University of Tuebingen, Tuebingen, Germany
| | - Marom Bikson
- Department of Biomedical Engineering, City College of New York, New York, NY, United States
| | - Marta Andreatta
- Department of Biological Psychology, Clinical Psychology and Psychotherapy, University of Würzburg, Würzburg, Germany
- Department of Psychology, Education and Child Studies, Erasmus University Rotterdam, Rotterdam, Netherlands
| | - Martina D'Agostini
- Research Group Health Psychology, Faculty of Psychology and Educational Sciences, University of Leuven, Leuven, Belgium
| | - Mathias Weymar
- Department of Biological Psychology and Affective Science, Faculty of Human Sciences, University of Potsdam, Potsdam, Germany
- Faculty of Health Sciences Brandenburg, University of Potsdam, Potsdam, Germany
| | - Matthew Betts
- Department of Anatomy, Faculty of Medicine, Mersin University, Mersin, Turkey
- Deutsches Zentrum für Neurodegenerative Erkrankungen (DZNE), Magdeburg, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke University, Magdeburg, Germany
| | - Matthias Prigge
- Neuromodulatory Networks, Leibniz Institute for Neurobiology, Magdeburg, Germany
| | - Michael Kaess
- University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
- Section for Translational Psychobiology in Child and Adolescent Psychiatry, Department of Child and Adolescent Psychiatry, Centre for Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
| | - Michael Roden
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany
- German Center for Diabetes Research, Munich, Germany
| | - Michelle Thai
- Department of Psychology, College of Liberal Arts, University of Minnesota, Minneapolis, MN, United States
| | - Nathaniel M. Schuster
- Department of Anesthesiology, Center for Pain Medicine, University of California, San Diego Health System, La Jolla, CA, United States
| | - Nicola Montano
- Department of Internal Medicine, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milan, Italy
- Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Niels Hansen
- Department of Psychiatry and Psychotherapy, University of Göttingen, Göttingen, Germany
- Laboratory of Systems Neuroscience and Imaging in Psychiatry (SNIPLab), University of Göttingen, Göttingen, Germany
| | - Nils B. Kroemer
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Peijing Rong
- Institute of Acupuncture and Moxibustion, China Academy of Chinese Medical Sciences, Beijing, China
| | - Rico Fischer
- Department of Psychology, University of Greifswald, Greifswald, Germany
| | - Robert H. Howland
- Department of Psychiatry, University of Pittsburgh School of Medicine, UPMC Western Psychiatric Hospital, Pittsburgh, PA, United States
| | - Roberta Sclocco
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States
- Department of Radiology, Logan University, Chesterfield, MO, United States
| | - Roberta Sellaro
- Cognitive Psychology Unit, Institute of Psychology, Leiden University, Leiden, Netherlands
- Leiden Institute for Brain and Cognition, Leiden, Netherlands
- Department of Developmental Psychology and Socialisation, University of Padova, Padova, Italy
| | - Ronald G. Garcia
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, United States
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, United States
| | - Sebastian Bauer
- Department of Neurology, Epilepsy Center Frankfurt Rhine-Main, Goethe-University Frankfurt, Frankfurt am Main, Germany
| | - Sofiya Gancheva
- Division of Endocrinology and Diabetology, Medical Faculty, Heinrich-Heine University Düsseldorf, Düsseldorf, Germany
- Institute for Clinical Diabetology, German Diabetes Center, Leibniz Center for Diabetes Research at Heinrich Heine University, Düsseldorf, Germany
- Heart Rhythm Institute, University of Oklahoma Health Sciences Center, Oklahoma City, OK, United States
| | - Stavros Stavrakis
- Faculty of Biological Science, School of Biomedical Science, University of Leeds, Leeds, United Kingdom
| | - Stefan Kampusch
- Institute of Electrodynamics, Microwave and Circuit Engineering, TU Wien, Vienna, Austria
- SzeleSTIM GmbH, Vienna, Austria
| | - Susan A. Deuchars
- School of Biomedical Science, Faculty of Biological Science, University of Leeds, Leeds, United Kingdom
| | - Sven Wehner
- Department of Surgery, University Hospital Bonn, Bonn, Germany
| | - Sylvain Laborde
- Department of Performance Psychology, Institute of Psychology, Deutsche Sporthochschule, Köln, Germany
| | - Taras Usichenko
- Department of Anesthesiology, University Medicine Greifswald, Greifswald, Germany
- Department of Anesthesia, McMaster University, Hamilton, ON, Canada
| | - Thomas Polak
- Laboratory of Functional Neurovascular Diagnostics, AG Early Diagnosis of Dementia, Department of Psychiatry, Psychosomatics and Psychotherapy, University Clinic Würzburg, Würzburg, Germany
| | - Tino Zaehle
- Department of Neurology, Otto-von-Guericke University, Magdeburg, Germany
| | - Uirassu Borges
- Department of Performance Psychology, Institute of Psychology, Deutsche Sporthochschule, Köln, Germany
- Department of Social and Health Psychology, Institute of Psychology, Deutsche Sporthochschule, Köln, Germany
| | - Vanessa Teckentrup
- Department of Psychiatry and Psychotherapy, University of Tübingen, Tübingen, Germany
| | - Vera K. Jandackova
- Department of Epidemiology and Public Health, Faculty of Medicine, University of Ostrava, Ostrava, Czechia
- Department of Human Movement Studies, Faculty of Education, University of Ostrava, Ostrava, Czechia
| | - Vitaly Napadow
- Department of Radiology, Athinoula A. Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, MA, United States
- Department of Radiology, Logan University, Chesterfield, MO, United States
| | - Julian Koenig
- University Hospital of Child and Adolescent Psychiatry and Psychotherapy, University of Bern, Bern, Switzerland
- Section for Experimental Child and Adolescent Psychiatry, Department of Child and Adolescent Psychiatry, Centre for Psychosocial Medicine, University of Heidelberg, Heidelberg, Germany
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Rangon CM, Krantic S, Moyse E, Fougère B. The Vagal Autonomic Pathway of COVID-19 at the Crossroad of Alzheimer's Disease and Aging: A Review of Knowledge. J Alzheimers Dis Rep 2020; 4:537-551. [PMID: 33532701 PMCID: PMC7835993 DOI: 10.3233/adr-200273] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/17/2020] [Indexed: 12/11/2022] Open
Abstract
Coronavirus Disease 2019 (COVID-19) pandemic-triggered mortality is significantly higher in older than in younger populations worldwide. Alzheimer's disease (AD) is related to aging and was recently reported to be among the major risk factors for COVID-19 mortality in older people. The symptomatology of COVID-19 indicates that lethal outcomes of infection rely on neurogenic mechanisms. The present review compiles the available knowledge pointing to the convergence of COVID-19 complications with the mechanisms of autonomic dysfunctions in AD and aging. The severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) is prone to neuroinvasion from the lung along the vagus nerve up to the brainstem autonomic nervous centers involved in the coupling of cardiovascular and respiratory rhythms. The brainstem autonomic network allows SARS-CoV-2 to trigger a neurogenic switch to hypertension and hypoventilation, which may act in synergy with aging- and AD-induced dysautonomias, along with an inflammatory "storm". The lethal outcomes of COVID-19, like in AD and unhealthy aging, likely rely on a critical hypoactivity of the efferent vagus nerve cholinergic pathway, which is involved in lowering cardiovascular pressure and systemic inflammation tone. We further discuss the emerging evidence supporting the use of 1) the non-invasive stimulation of vagus nerve as an additional therapeutic approach for severe COVID-19, and 2) the demonstrated vagal tone index, i.e., heart rate variability, via smartphone-based applications as a non-serological low-cost diagnostic of COVID-19. These two well-known medical approaches are already available and now deserve large-scale testing on human cohorts in the context of both AD and COVID-19.
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Affiliation(s)
- Claire-Marie Rangon
- Pain and Neuromodulation Unit, Division of Neurosurgery, Hôpital Fondation Ophtalmologique A. De Rothschild, Paris, France
| | - Slavica Krantic
- Sorbonne Université, St. Antoine Research Center (CRSA), Inserm UMRS-938, Hopital St-Antoine, Paris, France
| | - Emmanuel Moyse
- INRAE Centre Val-de-Loire, Physiology of Reproduction and Behavior Unit (PRC, UMR-85), Team ER2, Nouzilly, France
| | - Bertrand Fougère
- Division of Geriatric Medicine, Tours University Hospital, Tours, France
- Education, Ethics, Health (EA 7505), Tours University, Tours, France
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Stolero N, Frenkel D. The dialog between neurons and microglia in Alzheimer's disease: The neurotransmitters view. J Neurochem 2020; 158:1412-1424. [PMID: 33314073 DOI: 10.1111/jnc.15262] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Revised: 11/12/2020] [Accepted: 12/04/2020] [Indexed: 02/06/2023]
Abstract
Microglia play a vital role in maintaining brain homeostasis. Their continuous sensing of surrounding micro-environments is crucial for their activity. Cross talk between specific neurons and microglia might occur through specific neurotransmitter receptors on microglia. Impairment with this interaction might result in pathological activity of microglia against potential insults. The reason for this activity in many neurodegenerative diseases such as Alzheimer's disease (AD) is not known. However, several papers report of the effects of different neurotransmitter agonists on microglial cells function that relate to their activity in AD. This review aims to summarize those works and to raise potential fundamental questions for future research.
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Affiliation(s)
- Nofar Stolero
- Department of Neurobiology, School of Neurobiology, Biochemistry and Biophysics School, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
| | - Dan Frenkel
- Department of Neurobiology, School of Neurobiology, Biochemistry and Biophysics School, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel.,Sagol School of Neuroscience, George S. Wise Faculty of Life Sciences, Tel Aviv University, Tel Aviv, Israel
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Significance of vagus nerve function in terms of pathogenesis of psychosocial disorders. Neurochem Int 2020; 143:104934. [PMID: 33307153 DOI: 10.1016/j.neuint.2020.104934] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2020] [Revised: 11/26/2020] [Accepted: 12/02/2020] [Indexed: 12/13/2022]
Abstract
The vagus nerve (VN) belongs to the parasympathetic nervous system, which is well known to be involved in the regulation of the functions of organs in the body. The neurotransmitter acetylcholine, released from the cholinergic system including VN, has been known to play an anti-inflammatory role through the efferent pathways in regulating peripheral inflammatory responses profoundly involved in the pathogenesis of diseases. In contrast, anatomically, it connects the central nervous system (CNS) and peripheral organs, including the heart and gastrointestinal (GI) tract. Therefore, it has been recently reported that the VN also plays an important role in the pathogenesis of psychological disorders since it confers varied signals from the GI tract to the CNS, and alteration of microbiota residing in GI definitely influences the condition of neuropsychiatric disorders. Furthermore, the CNS includes microglia, a neuroinflammatory effector in the brain, which is also influenced by the VN to modulate its inflammatory status. Based on significant findings of the VN, the VN stimulation (VNS) has recently drawn attention from many scientific fields. VNS was initially applied to patients with refractory epilepsy, followed by patients with refractory depression. Subsequently, VNS was also attempted to be introduced to other diseases. However, against whichever disease, central or peripheral, detailed underlying mechanisms of VNS involved in neuropsychiatric disorders as well as VNS target molecules in the GI tract and the CNS remains to be studied. In this review, we discuss the mechanisms and predicted responsible factors of VNS in terms of neuropsychiatric disorders.
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Lee SK, Jeakins GS, Tukiainen A, Hewage E, Armitage OE. Next-Generation Bioelectric Medicine: Harnessing the Therapeutic Potential of Neural Implants. Bioelectricity 2020; 2:321-327. [PMID: 34476364 DOI: 10.1089/bioe.2020.0044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Bioelectric medicine leverages natural signaling pathways in the nervous system to counteract organ dysfunction. This novel approach has potential to address conditions with unmet needs, including heart failure, hypertension, inflammation, arthritis, asthma, Alzheimer's disease, and diabetes. Neural therapies, which target the brain, spinal cord, or peripheral nerves, are already being applied to conditions such as epilepsy, Parkinson's, and chronic pain. While today's therapies have made exciting advancements, their open-loop design-where stimulation is administered without collecting feedback-means that results can be variable and devices do not work for everyone. Stimulation effects are sensitive to changes in neural tissue, nerve excitability, patient position, and more. Closing the loop by providing neural or non-neural biomarkers to the system can guide therapy by providing additional insights into stimulation effects and overall patient condition. Devices currently on the market use recorded biomarkers to close the loop and improve therapy. The future of bioelectric medicine is more holistically personalized. Collected data will be used for increasingly precise application of neural stimulations to achieve therapeutic effects. To achieve this future, advances are needed in device design, implanted and computational technologies, and scientific/medical interpretation of neural activity. Research and commercial devices are enabling the development of multiple levels of responsiveness to neural, physiological, and environmental changes. This includes developing suitable implanted technologies for high bandwidth brain/machine interfaces and addressing the challenge of neural or state biomarker decoding. Consistent progress is being made in these challenges toward the long-term vision of automatically and holistically personalized care for chronic health conditions.
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Ano Y, Ohya R, Yamazaki T, Takahashi C, Taniguchi Y, Kondo K, Takashima A, Uchida K, Nakayama H. Hop bitter acids containing a β-carbonyl moiety prevent inflammation-induced cognitive decline via the vagus nerve and noradrenergic system. Sci Rep 2020; 10:20028. [PMID: 33208787 PMCID: PMC7674441 DOI: 10.1038/s41598-020-77034-w] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 11/03/2020] [Indexed: 12/19/2022] Open
Abstract
The prevention of age-related cognitive decline and dementia is becoming a high priority because of the rapid growth of aging populations. We have previously shown that hop bitter acids such as iso-α-acids (IAAs) and matured hop bitter acids (MHBAs) activate the vagus nerve and improve memory impairment. Moreover, supplements with MHBAs were shown to improve memory retrieval in older adults. However, the underlying mechanisms have not been entirely elucidated. We aimed to investigate the effects of MHBAs and the common β-tricarbonyl moiety on memory impairment induced by the activation of microglia and the loss of the noradrenergic system. MHBAs and a model compound with β-tricarbonyl moiety were administered to LPS-inoculated mice and 5 × FAD Alzheimer’s disease (AD) model mice, following the evaluation in behavioral tests and microglial activation. To evaluate the association of noradrenaline with MHBAs effects, mice treated with N-(2-chloroethyl)-N-ethyl-2-bromobenzylamine (DSP-4), a noradrenergic neurotoxin that selectively damages noradrenergic projections from the locus coeruleus, were subjected to the behavioral evaluation. MHBAs reduced brain inflammation and improved LPS-induced memory impairment. A model compound possessing the β-tricarbonyl moiety improved the LPS-induced memory impairment and neuronal loss via the vagus nerve. Additionally, the protective effects of MHBAs on memory impairment were attenuated by noradrenaline depletion using DSP-4. MHBAs suppressed the activation of microglia and improved the memory impairment in 5 × FAD mice, which was also attenuated by noradrenaline depletion. Treatment with MHBAs increased cholecystokinin production from the intestinal cells. Generally, cholecystokinin activates the vagal nerve, which stimulate the noradrenergic neuron in the locus ceruleus. Taken together, our results reveal that food ingredients such as hop bitter acids with a β-tricarbonyl moiety suppress microglial activation and improve memory impairment induced by inflammation or AD pathology via the activation of the gut-brain axis and noradrenergic system. Supplements with hop bitter acids, including MHBAs, might be a novel approach for the prevention of cognitive decline and dementia.
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Affiliation(s)
- Yasuhisa Ano
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo, 113-8657, Japan. .,Kirin Central Research Institute, Kirin Holdings Company Ltd, 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa, 236-0004, Japan.
| | - Rena Ohya
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo, 113-8657, Japan.,Kirin Central Research Institute, Kirin Holdings Company Ltd, 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa, 236-0004, Japan
| | - Takahiro Yamazaki
- Kirin Central Research Institute, Kirin Holdings Company Ltd, 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa, 236-0004, Japan
| | - Chika Takahashi
- Kirin Central Research Institute, Kirin Holdings Company Ltd, 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa, 236-0004, Japan
| | - Yoshimasa Taniguchi
- Kirin Central Research Institute, Kirin Holdings Company Ltd, 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa, 236-0004, Japan
| | - Keiji Kondo
- Kirin Central Research Institute, Kirin Holdings Company Ltd, 1-13-5 Fukuura Kanazawa-ku, Yokohama-shi, Kanagawa, 236-0004, Japan
| | | | - Kazuyuki Uchida
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo, 113-8657, Japan
| | - Hiroyuki Nakayama
- Laboratory of Veterinary Pathology, Graduate School of Agricultural and Life Sciences, the University of Tokyo, Tokyo, 113-8657, Japan
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Borsom EM, Lee K, Cope EK. Do the Bugs in Your Gut Eat Your Memories? Relationship between Gut Microbiota and Alzheimer's Disease. Brain Sci 2020; 10:E814. [PMID: 33153085 PMCID: PMC7693835 DOI: 10.3390/brainsci10110814] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 02/06/2023] Open
Abstract
The human microbiota is composed of trillions of microbial cells inhabiting the oral cavity, skin, gastrointestinal (GI) tract, airways, and reproductive organs. The gut microbiota is composed of dynamic communities of microorganisms that communicate bidirectionally with the brain via cytokines, neurotransmitters, hormones, and secondary metabolites, known as the gut microbiota-brain axis. The gut microbiota-brain axis is suspected to be involved in the development of neurological diseases, including Alzheimer's disease (AD), Parkinson's disease, and Autism Spectrum Disorder. AD is an irreversible, neurodegenerative disease of the central nervous system (CNS), characterized by amyloid-β plaques, neurofibrillary tangles, and neuroinflammation. Microglia and astrocytes, the resident immune cells of the CNS, play an integral role in AD development, as neuroinflammation is a driving factor of disease severity. The gut microbiota-brain axis is a novel target for Alzheimer's disease therapeutics to modulate critical neuroimmune and metabolic pathways. Potential therapeutics include probiotics, prebiotics, fecal microbiota transplantation, and dietary intervention. This review summarizes our current understanding of the role of the gut microbiota-brain axis and neuroinflammation in the onset and development of Alzheimer's disease, limitations of current research, and potential for gut microbiota-brain axis targeted therapies.
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Abstract
The innate immune system in the central nervous system (CNS) is mainly represented by specialized tissue-resident macrophages, called microglia. In the past years, various species-, host- and tissue-specific as well as environmental factors were recognized that essentially affect microglial properties and functions in the healthy and diseased brain. Host microbiota are mostly residing in the gut and contribute to microglial activation states, for example, via short-chain fatty acids (SCFAs) or aryl hydrocarbon receptor (AhR) ligands. Thereby, the gut microorganisms are deemed to influence numerous CNS diseases mediated by microglia. In this review, we summarize recent findings of the interaction between the host microbiota and the CNS in health and disease, where we specifically highlight the resident gut microbiota as a crucial environmental factor for microglial function as what we coin "the microbiota-microglia axis."
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Affiliation(s)
- Omar Mossad
- Institute of NeuropathologyFaculty of MedicineUniversity of FreiburgFreiburgGermany
- Faculty of BiologyUniversity of FreiburgFreiburgGermany
| | - Daniel Erny
- Institute of NeuropathologyFaculty of MedicineUniversity of FreiburgFreiburgGermany
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Gamage R, Wagnon I, Rossetti I, Childs R, Niedermayer G, Chesworth R, Gyengesi E. Cholinergic Modulation of Glial Function During Aging and Chronic Neuroinflammation. Front Cell Neurosci 2020; 14:577912. [PMID: 33192323 PMCID: PMC7594524 DOI: 10.3389/fncel.2020.577912] [Citation(s) in RCA: 68] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 09/07/2020] [Indexed: 12/12/2022] Open
Abstract
Aging is a complex biological process that increases the risk of age-related cognitive degenerative diseases such as dementia, including Alzheimer’s disease (AD), Lewy Body Dementia (LBD), and mild cognitive impairment (MCI). Even non-pathological aging of the brain can involve chronic oxidative and inflammatory stress, which disrupts the communication and balance between the brain and the immune system. There has been an increasingly strong connection found between chronic neuroinflammation and impaired memory, especially in AD. While microglia and astrocytes, the resident immune cells of the central nervous system (CNS), exerting beneficial effects during the acute inflammatory phase, during chronic neuroinflammation they can become more detrimental. Central cholinergic circuits are involved in maintaining normal cognitive function and regulating signaling within the entire cerebral cortex. While neuronal-glial cholinergic signaling is anti-inflammatory and anti-oxidative, central cholinergic neuronal degeneration is implicated in impaired learning, memory sleep regulation, and attention. Although there is evidence of cholinergic involvement in memory, fewer studies have linked the cholinergic anti-inflammatory and anti-oxidant pathways to memory processes during development, normal aging, and disease states. This review will summarize the current knowledge of cholinergic effects on microglia and astroglia, and their role in both anti-inflammatory and anti-oxidant mechanisms, concerning normal aging and chronic neuroinflammation. We provided details on how stimulation of α7 nicotinic acetylcholine (α7nACh) receptors can be neuroprotective by increasing amyloid-β phagocytosis, decreasing inflammation and reducing oxidative stress by promoting the nuclear factor erythroid 2-related factor 2 (Nrf2) pathways and decreasing the release of pro-inflammatory cytokines. There is also evidence for astroglial α7nACh receptor stimulation mediating anti-inflammatory and antioxidant effects by inhibiting the nuclear factor-κB (NF-κB) pathway and activating the Nrf2 pathway respectively. We conclude that targeting cholinergic glial interactions between neurons and glial cells via α7nACh receptors could regulate neuroinflammation and oxidative stress, relevant to the treatment of several neurodegenerative diseases.
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Affiliation(s)
- Rashmi Gamage
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ingrid Wagnon
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ilaria Rossetti
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Ryan Childs
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Garry Niedermayer
- School of Science, Western Sydney University, Penrith, NSW, Australia
| | - Rose Chesworth
- School of Medicine, Western Sydney University, Penrith, NSW, Australia
| | - Erika Gyengesi
- Department of Pharmacology, School of Medicine, Western Sydney University, Penrith, NSW, Australia
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50
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Staats P, Giannakopoulos G, Blake J, Liebler E, Levy RM. The Use of Non-invasive Vagus Nerve Stimulation to Treat Respiratory Symptoms Associated With COVID-19: A Theoretical Hypothesis and Early Clinical Experience. Neuromodulation 2020; 23:784-788. [PMID: 32342609 PMCID: PMC7267613 DOI: 10.1111/ner.13172] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Revised: 04/23/2020] [Accepted: 04/23/2020] [Indexed: 12/21/2022]
Abstract
OBJECTIVES Coronavirus disease 2019 (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is a pandemic with no specific therapeutic agents and substantial mortality, and finding new treatments is critical. Most cases are mild, but a significant minority of patients develop moderate to severe respiratory symptoms, with the most severe cases requiring intensive care and/or ventilator support. This respiratory compromise appears to be due to a hyperimmune reaction, often called a cytokine storm. Vagus nerve stimulation has been demonstrated to block production of cytokines in sepsis and other medical conditions. We hypothesize that non-invasive vagus nerve stimulation (nVNS) might provide clinical benefits in patients with respiratory symptoms similar to those associated with COVID-19. MATERIALS AND METHODS Information on two case reports was obtained via email correspondence and phone interviews with the patients. RESULTS Both patients reported clinically meaningful benefits from nVNS therapy. In case 1, the patient used nVNS to expedite symptomatic recovery at home after hospital discharge and was able to discontinue use of opioid and cough suppressant medications. In case 2, the patient experienced immediate and consistent relief from symptoms of chest tightness and shortness of breath, as well as an improved ability to clear his lungs. CONCLUSIONS Preliminary observations and a strong scientific foundation suggest that nVNS might provide clinical benefits in patients with COVID-19 via multiple mechanisms.
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