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Lanni I, Chiacchierini G, Papagno C, Santangelo V, Campolongo P. Treating Alzheimer's Disease with Brain Stimulation: From preclinical models to non-invasive stimulation in humans. Neurosci Biobehav Rev 2024:105831. [PMID: 39074672 DOI: 10.1016/j.neubiorev.2024.105831] [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: 05/20/2024] [Revised: 07/20/2024] [Accepted: 07/24/2024] [Indexed: 07/31/2024]
Abstract
Alzheimer's disease (AD) is a severe and progressive neurodegenerative condition that exerts detrimental effects on brain function. As of now, there is no effective treatment for AD patients. This review explores two distinct avenues of research. The first revolves around the use of animal studies and preclinical models to gain insights into AD's underlying mechanisms and potential treatment strategies. Specifically, it delves into the effectiveness of interventions such as Optogenetics and Chemogenetics, shedding light on their implications for understanding pathophysiological mechanisms and potential therapeutic applications. The second avenue focuses on non-invasive brain stimulation (NiBS) techniques in the context of AD. Evidence suggests that NiBS can successfully modulate cognitive functions associated with various neurological and neuropsychiatric disorders, including AD, as demonstrated by promising findings. Here, we critically assessed recent findings in AD research belonging to these lines of research and discuss their potential impact on the clinical horizon of AD treatment. These multifaceted approaches offer hope for advancing our comprehension of AD pathology and developing novel therapeutic interventions.
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Affiliation(s)
- Ilenia Lanni
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy; Behavioral Neuropharmacology Unit, IRCSS Santa Lucia Foundation, Rome, Italy
| | - Giulia Chiacchierini
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy; Behavioral Neuropharmacology Unit, IRCSS Santa Lucia Foundation, Rome, Italy
| | - Costanza Papagno
- Center for Mind/Brain Sciences (CIMeC), University of Trento, Rovereto, Italy
| | - Valerio Santangelo
- Functional Neuroimaging Laboratory, IRCCS Santa Lucia Foundation, Rome, Italy; Department of Philosophy, Social Sciences & Education, University of Perugia, Perugia, Italy
| | - Patrizia Campolongo
- Department of Physiology and Pharmacology, Sapienza University of Rome, Rome, Italy; Behavioral Neuropharmacology Unit, IRCSS Santa Lucia Foundation, Rome, Italy.
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2
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Soleimani G, Nitsche MA, Bergmann TO, Towhidkhah F, Violante IR, Lorenz R, Kuplicki R, Tsuchiyagaito A, Mulyana B, Mayeli A, Ghobadi-Azbari P, Mosayebi-Samani M, Zilverstand A, Paulus MP, Bikson M, Ekhtiari H. Closing the loop between brain and electrical stimulation: towards precision neuromodulation treatments. Transl Psychiatry 2023; 13:279. [PMID: 37582922 PMCID: PMC10427701 DOI: 10.1038/s41398-023-02565-5] [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: 07/08/2022] [Revised: 07/06/2023] [Accepted: 07/20/2023] [Indexed: 08/17/2023] Open
Abstract
One of the most critical challenges in using noninvasive brain stimulation (NIBS) techniques for the treatment of psychiatric and neurologic disorders is inter- and intra-individual variability in response to NIBS. Response variations in previous findings suggest that the one-size-fits-all approach does not seem the most appropriate option for enhancing stimulation outcomes. While there is a growing body of evidence for the feasibility and effectiveness of individualized NIBS approaches, the optimal way to achieve this is yet to be determined. Transcranial electrical stimulation (tES) is one of the NIBS techniques showing promising results in modulating treatment outcomes in several psychiatric and neurologic disorders, but it faces the same challenge for individual optimization. With new computational and methodological advances, tES can be integrated with real-time functional magnetic resonance imaging (rtfMRI) to establish closed-loop tES-fMRI for individually optimized neuromodulation. Closed-loop tES-fMRI systems aim to optimize stimulation parameters based on minimizing differences between the model of the current brain state and the desired value to maximize the expected clinical outcome. The methodological space to optimize closed-loop tES fMRI for clinical applications includes (1) stimulation vs. data acquisition timing, (2) fMRI context (task-based or resting-state), (3) inherent brain oscillations, (4) dose-response function, (5) brain target trait and state and (6) optimization algorithm. Closed-loop tES-fMRI technology has several advantages over non-individualized or open-loop systems to reshape the future of neuromodulation with objective optimization in a clinically relevant context such as drug cue reactivity for substance use disorder considering both inter and intra-individual variations. Using multi-level brain and behavior measures as input and desired outcomes to individualize stimulation parameters provides a framework for designing personalized tES protocols in precision psychiatry.
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Affiliation(s)
- Ghazaleh Soleimani
- Department of Psychiatry & Behavioral Sciences, University of Minnesota, Minneapolis, MN, USA
- Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Michael A Nitsche
- Department of Psychology and Neuroscience, Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany
- Bielefeld University, University Hospital OWL, Protestant Hospital of Bethel Foundation, University Clinic of Psychiatry and Psychotherapy, and University Clinic of Child and Adolescent Psychiatry and Psychotherapy, Bielefeld, Germany
| | - Til Ole Bergmann
- Neuroimaging Center, Focus Program Translational Neuroscience, Johannes Gutenberg University Medical Center Mainz, Mainz, Germany
- Leibniz Institute for Resilience Research, Mainz, Germany
| | - Farzad Towhidkhah
- Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, Iran
| | - Ines R Violante
- School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Guilford, UK
| | - Romy Lorenz
- Department of Psychology, Stanford University, Stanford, CA, USA
- MRC CBU, University of Cambridge, Cambridge, UK
- Department of Neurophysics, MPI, Leipzig, Germany
| | | | | | - Beni Mulyana
- Laureate Institute for Brain Research, Tulsa, OK, USA
- School of Electrical and Computer Engineering, University of Oklahoma, Tulsa, OK, USA
| | - Ahmad Mayeli
- University of Pittsburgh Medical Center, Pittsburg, PA, USA
| | - Peyman Ghobadi-Azbari
- Department of Biomedical Engineering, Shahed University, Tehran, Iran
- Iranian National Center for Addiction Studies, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohsen Mosayebi-Samani
- Department of Psychology and Neuroscience, Leibniz Research Center for Working Environment and Human Factors, Dortmund, Germany
| | - Anna Zilverstand
- Department of Psychiatry & Behavioral Sciences, University of Minnesota, Minneapolis, MN, USA
| | | | | | - Hamed Ekhtiari
- Department of Psychiatry & Behavioral Sciences, University of Minnesota, Minneapolis, MN, USA.
- Laureate Institute for Brain Research, Tulsa, OK, USA.
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3
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Lu H, Li J, Yang NS, Lam LCW, Ma SL, Wing YK, Zhang L. Using gamma-band transcranial alternating current stimulation (tACS) to improve sleep quality and cognition in patients with mild neurocognitive disorders due to Alzheimer's disease: A study protocol for a randomized controlled trial. PLoS One 2023; 18:e0289591. [PMID: 37540692 PMCID: PMC10403094 DOI: 10.1371/journal.pone.0289591] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2023] [Accepted: 07/21/2023] [Indexed: 08/06/2023] Open
Abstract
BACKGROUND Sleep disturbances are highly prevalent in patients with age-related neurodegenerative diseases, which severely affect cognition and even lead to accumulated β-amyloid. Encouraging results from recent studies on transcranial direct current stimulation (tDCS) showed moderate positive effects on sleep quality in preclinical Alzheimer's disease (AD). Compared to tDCS, transcranial alternating current stimulation (tACS) enables the entrainment of neuronal activity with optimized focality through injecting electric current with a specific frequency and has significant enhancement effects on slow wave activities. METHODS AND DESIGN This is a randomized, double-blind, sham-controlled clinical trial comparing 40 Hz tACS with tDCS in mild neurocognitive disorders due to AD with sleep disturbances. Magnetic resonance imaging (MRI) data is used to construct personalized realistic head model. Treatment outcomes, including sleep quality, cognitive performance and saliva Aβ levels will be conducted at baseline, 4th week, 8th week, 12th week and 24th week. CONCLUSIONS It is expected that the repeated gamma-band tACS will show significant improvements in sleep quality and cognitive functions compared to tDCS and sham tDCS. The findings will provide high-level evidence and guide further advanced studies in the field of neurodegenerative diseases and sleep medicine. TRIAL REGISTRATION ClinicalTrials.gov Identifier: NCT05544201.
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Affiliation(s)
- Hanna Lu
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China
- The Affiliated Brain Hospital of Guangzhou Medical University, Guangzhou, China
| | - Jing Li
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Natalie Shu Yang
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Linda Chiu Wa Lam
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Suk Ling Ma
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yun Kwok Wing
- Department of Psychiatry, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Li Zhang
- Department of Mechanical and Automation Engineering, The Chinese University of Hong Kong, Hong Kong SAR, China
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4
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Closed-Loop tACS Delivered during Slow-Wave Sleep Reduces Retroactive Interference on a Paired-Associates Learning Task. Brain Sci 2023; 13:brainsci13030468. [PMID: 36979277 PMCID: PMC10046133 DOI: 10.3390/brainsci13030468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 03/03/2023] [Accepted: 03/06/2023] [Indexed: 03/12/2023] Open
Abstract
Previous studies have found a benefit of closed-loop transcranial alternating current stimulation (CL-tACS) matched to ongoing slow-wave oscillations (SWO) during sleep on memory consolidation for words in a paired associates task (PAT). Here, we examined the effects of CL-tACS in a retroactive interference PAT (ri-PAT) paradigm, where additional stimuli were presented to increase interference and reduce memory performance. Thirty-one participants were tested on a PAT before sleep, and CL-tACS was applied over the right and left DLPFC (F3 and F4) vs. mastoids for five cycles after detection of the onset of each discrete event of SWO during sleep. Participants were awoken the following morning, learned a new PAT list, and then were tested on the original list. There was a significant effect of stimulation condition (p = 0.04297; Cohen’s d = 0.768), where verum stimulation resulted in reduced retroactive interference compared with sham and a significant interaction of encoding strength and stimulation condition (p = 0.03591). Planned simple effects testing within levels of encoding revealed a significant effect of stimulation only for low-encoders (p = 0.0066; Cohen’s d = 1.075) but not high-encoders. We demonstrate here for the first time that CL-tACS during sleep can enhance the protective benefits on retroactive interference in participants who have lower encoding aptitude.
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Chen X, Ma R, Zhang W, Zeng GQ, Wu Q, Yimiti A, Xia X, Cui J, Liu Q, Meng X, Bu J, Chen Q, Pan Y, Yu NX, Wang S, Deng ZD, Sack AT, Laughlin MM, Zhang X. Alpha oscillatory activity is causally linked to working memory retention. PLoS Biol 2023; 21:e3001999. [PMID: 36780560 PMCID: PMC9983870 DOI: 10.1371/journal.pbio.3001999] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 03/03/2023] [Accepted: 01/12/2023] [Indexed: 02/15/2023] Open
Abstract
Although previous studies have reported correlations between alpha oscillations and the "retention" subprocess of working memory (WM), causal evidence has been limited in human neuroscience due to the lack of delicate modulation of human brain oscillations. Conventional transcranial alternating current stimulation (tACS) is not suitable for demonstrating the causal evidence for parietal alpha oscillations in WM retention because of its inability to modulate brain oscillations within a short period (i.e., the retention subprocess). Here, we developed an online phase-corrected tACS system capable of precisely correcting for the phase differences between tACS and concurrent endogenous oscillations. This system permits the modulation of brain oscillations at the target stimulation frequency within a short stimulation period and is here applied to empirically demonstrate that parietal alpha oscillations causally relate to WM retention. Our experimental design included both in-phase and anti-phase alpha-tACS applied to participants during the retention subprocess of a modified Sternberg paradigm. Compared to in-phase alpha-tACS, anti-phase alpha-tACS decreased both WM performance and alpha activity. These findings strongly support a causal link between alpha oscillations and WM retention and illustrate the broad application prospects of phase-corrected tACS.
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Affiliation(s)
- Xueli Chen
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
- Department of Social and Behavioural Sciences, City University of Hong Kong, Hong Kong, People’s Republic of China
| | - Ru Ma
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
| | - Wei Zhang
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
| | - Ginger Qinghong Zeng
- Application Technology Center of Physical Therapy to Brain Disorders, Institute of Advanced Technology, University of Science & Technology of China, Hefei, China
| | - Qianying Wu
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
- Division of Humanities and Social Sciences, California Institute of Technology, Pasadena, California, United States of America
| | - Ajiguli Yimiti
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
| | - Xinzhao Xia
- Centers for Biomedical Engineering, School of Information Science and Technology, University of Science & Technology of China, Hefei, China
| | - Jiangtian Cui
- Centers for Biomedical Engineering, School of Information Science and Technology, University of Science & Technology of China, Hefei, China
- School of Optometry and Vision Science, Cardiff University, Cardiff, United Kingdom
| | - Qiongwei Liu
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
| | - Xueer Meng
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
| | - Junjie Bu
- School of Biomedical Engineering, Anhui Medical University, Hefei, China
| | - Qi Chen
- School of Psychology, South China Normal University, Guangzhou, China
| | - Yu Pan
- Shanghai Key Laboratory of Brain-Machine Intelligence for Information Behavior, School of Business and Management, Shanghai International Studies University, Shanghai, China
| | - Nancy Xiaonan Yu
- Department of Social and Behavioural Sciences, City University of Hong Kong, Hong Kong, People’s Republic of China
| | - Shouyan Wang
- Institute of Science and Technology for Brain-inspired Intelligence, Fudan University, Shanghai, China
| | - Zhi-De Deng
- Noninvasive Neuromodulation Unit, Experimental Therapeutics & Pathophysiology Branch, Intramural Research Program, National Institute of Mental Health, National Institutes of Health, Bethesda, USA
| | - Alexander T. Sack
- Department of Cognitive Neuroscience, Faculty of Psychology and Neuroscience, Maastricht University, Maastricht, The Netherlands
| | - Myles Mc Laughlin
- Exp ORL, Department of Neuroscience, Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Xiaochu Zhang
- Department of Radiology, the First Affiliated Hospital of USTC, Hefei National Research Center for Physical Sciences at the Microscale and School of Life Science, Division of Life Science and Medicine, University of Science & Technology of China, Hefei, China
- Application Technology Center of Physical Therapy to Brain Disorders, Institute of Advanced Technology, University of Science & Technology of China, Hefei, China
- Department of Psychology, School of Humanities & Social Science, University of Science & Technology of China, Hefei, China
- Institute of Health and Medicine, Hefei Comprehensive National Science Center, Hefei, China
- * E-mail:
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6
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Robert BM, Jones AP, Mullins TS, Trumbo MCS, Ketz NA, Howard MD, Pilly PK, Clark VP. Closed-loop transcranial alternating current stimulation of slow wave oscillations during sleep reduces declarative learning the next day. Brain Stimul 2022; 15:1565-1566. [PMID: 36496127 DOI: 10.1016/j.brs.2022.12.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 12/01/2022] [Accepted: 12/05/2022] [Indexed: 12/13/2022] Open
Affiliation(s)
- Bradley M Robert
- Psychology Clinical Neuroscience Center, Dept. Psychology, UNM, Albuquerque, NM, 87131, USA
| | - Aaron P Jones
- Psychology Clinical Neuroscience Center, Dept. Psychology, UNM, Albuquerque, NM, 87131, USA
| | - Teagan S Mullins
- Psychology Clinical Neuroscience Center, Dept. Psychology, UNM, Albuquerque, NM, 87131, USA
| | - Michael C S Trumbo
- Psychology Clinical Neuroscience Center, Dept. Psychology, UNM, Albuquerque, NM, 87131, USA
| | - Nicholas A Ketz
- Proficient Autonomy Center, Intelligent Systems Laboratory, HRL Laboratories, Malibu, CA, 90265, USA
| | - Michael D Howard
- Proficient Autonomy Center, Intelligent Systems Laboratory, HRL Laboratories, Malibu, CA, 90265, USA
| | - Praveen K Pilly
- Proficient Autonomy Center, Intelligent Systems Laboratory, HRL Laboratories, Malibu, CA, 90265, USA
| | - Vincent P Clark
- Psychology Clinical Neuroscience Center, Dept. Psychology, UNM, Albuquerque, NM, 87131, USA.
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7
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Antal A, Luber B, Brem AK, Bikson M, Brunoni AR, Cohen Kadosh R, Dubljević V, Fecteau S, Ferreri F, Flöel A, Hallett M, Hamilton RH, Herrmann CS, Lavidor M, Loo C, Lustenberger C, Machado S, Miniussi C, Moliadze V, Nitsche MA, Rossi S, Rossini PM, Santarnecchi E, Seeck M, Thut G, Turi Z, Ugawa Y, Venkatasubramanian G, Wenderoth N, Wexler A, Ziemann U, Paulus W. Non-invasive brain stimulation and neuroenhancement. Clin Neurophysiol Pract 2022; 7:146-165. [PMID: 35734582 PMCID: PMC9207555 DOI: 10.1016/j.cnp.2022.05.002] [Citation(s) in RCA: 55] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 04/19/2022] [Accepted: 05/18/2022] [Indexed: 12/15/2022] Open
Abstract
The available data frame with a wide parameter space of tES does not allow an overarching protocol recommendation. Established engineering risk-management procedures with regard to manufacturing should be followed. Consensus among experts is that tES for neuroenhancement is safe as long as tested protocols are followed.
Attempts to enhance human memory and learning ability have a long tradition in science. This topic has recently gained substantial attention because of the increasing percentage of older individuals worldwide and the predicted rise of age-associated cognitive decline in brain functions. Transcranial brain stimulation methods, such as transcranial magnetic (TMS) and transcranial electric (tES) stimulation, have been extensively used in an effort to improve cognitive functions in humans. Here we summarize the available data on low-intensity tES for this purpose, in comparison to repetitive TMS and some pharmacological agents, such as caffeine and nicotine. There is no single area in the brain stimulation field in which only positive outcomes have been reported. For self-directed tES devices, how to restrict variability with regard to efficacy is an essential aspect of device design and function. As with any technique, reproducible outcomes depend on the equipment and how well this is matched to the experience and skill of the operator. For self-administered non-invasive brain stimulation, this requires device designs that rigorously incorporate human operator factors. The wide parameter space of non-invasive brain stimulation, including dose (e.g., duration, intensity (current density), number of repetitions), inclusion/exclusion (e.g., subject’s age), and homeostatic effects, administration of tasks before and during stimulation, and, most importantly, placebo or nocebo effects, have to be taken into account. The outcomes of stimulation are expected to depend on these parameters and should be strictly controlled. The consensus among experts is that low-intensity tES is safe as long as tested and accepted protocols (including, for example, dose, inclusion/exclusion) are followed and devices are used which follow established engineering risk-management procedures. Devices and protocols that allow stimulation outside these parameters cannot claim to be “safe” where they are applying stimulation beyond that examined in published studies that also investigated potential side effects. Brain stimulation devices marketed for consumer use are distinct from medical devices because they do not make medical claims and are therefore not necessarily subject to the same level of regulation as medical devices (i.e., by government agencies tasked with regulating medical devices). Manufacturers must follow ethical and best practices in marketing tES stimulators, including not misleading users by referencing effects from human trials using devices and protocols not similar to theirs.
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Affiliation(s)
- Andrea Antal
- Department of Neurology, University Medical Center, Göttingen, Germany
- Corresponding author at: Department of Neurology, University Medical Center, Göttingen, Robert Koch Str. 40, 37075 Göttingen, Germany.
| | - Bruce Luber
- Noninvasive Neuromodulation Unit, Experimental Therapeutics and Pathophysiology Branch, National Institute of Mental Health, Bethesda, MD, USA
| | - Anna-Katharine Brem
- University Hospital of Old Age Psychiatry, University of Bern, Bern, Switzerland
- Department of Old Age Psychiatry, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, United Kingdom
| | - Marom Bikson
- Biomedical Engineering at the City College of New York (CCNY) of the City University of New York (CUNY), NY, USA
| | - Andre R. Brunoni
- Departamento de Clínica Médica e de Psiquiatria, Faculdade de Medicina da Universidade de São Paulo, São Paulo, Brazil
- Service of Interdisciplinary Neuromodulation (SIN), Laboratory of Neurosciences (LIM-27), Institute of Psychiatry, Hospital das Clínicas da Faculdade de Medicina da USP, São Paulo, Brazil
| | - Roi Cohen Kadosh
- School of Psychology, Faculty of Health and Medical Sciences, University of Surrey, Guildford GU2 7XH, UK
| | - Veljko Dubljević
- Science, Technology and Society Program, College of Humanities and Social Sciences, North Carolina State University, Raleigh, NC, USA
| | - Shirley Fecteau
- Department of Psychiatry and Neurosciences, Faculty of Medicine, Université Laval, CERVO Brain Research Centre, Centre intégré universitaire en santé et services sociaux de la Capitale-Nationale, Quebec City, Quebec, Canada
| | - Florinda Ferreri
- Unit of Neurology, Unit of Clinical Neurophysiology, Study Center of Neurodegeneration (CESNE), Department of Neuroscience, University of Padua, Padua, Italy
- Department of Clinical Neurophysiology, Kuopio University Hospital, University of Eastern Finland, Kuopio, Finland
| | - Agnes Flöel
- Department of Neurology, Universitätsmedizin Greifswald, 17475 Greifswald, Germany
- German Centre for Neurodegenerative Diseases (DZNE) Standort Greifswald, 17475 Greifswald, Germany
| | - Mark Hallett
- Human Motor Control Section, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, USA
| | - Roy H. Hamilton
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Christoph S. Herrmann
- Experimental Psychology Lab, Department of Psychology, Carl von Ossietzky Universität, Oldenburg, Germany
| | - Michal Lavidor
- Department of Psychology and the Gonda Brain Research Center, Bar Ilan University, Israel
| | - Collen Loo
- School of Psychiatry and Black Dog Institute, University of New South Wales; The George Institute; Sydney, Australia
| | - Caroline Lustenberger
- Neural Control of Movement Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
| | - Sergio Machado
- Department of Sports Methods and Techniques, Federal University of Santa Maria, Santa Maria, Brazil
- Laboratory of Physical Activity Neuroscience, Neurodiversity Institute, Queimados-RJ, Brazil
| | - Carlo Miniussi
- Center for Mind/Brain Sciences – CIMeC and Centre for Medical Sciences - CISMed, University of Trento, Rovereto, Italy
| | - Vera Moliadze
- Institute of Medical Psychology and Medical Sociology, University Medical Center Schleswig Holstein, Kiel University, Kiel, Germany
| | - Michael A Nitsche
- Department Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors at TU, Dortmund, Germany
- Dept. Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany
| | - Simone Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Unit of Neurology and Clinical Neurophysiology, Department of Medicine, Surgery and Neuroscience, University of Siena, Italy
| | - Paolo M. Rossini
- Department of Neuroscience and Neurorehabilitation, Brain Connectivity Lab, IRCCS-San Raffaele-Pisana, Rome, Italy
| | - Emiliano Santarnecchi
- Precision Neuroscience and Neuromodulation Program, Gordon Center for Medical Imaging, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
| | - Margitta Seeck
- Department of Clinical Neurosciences, Hôpitaux Universitaires de Genève, Switzerland
| | - Gregor Thut
- Centre for Cognitive Neuroimaging, School of Psychology and Neuroscience, EEG & Epolepsy Unit, University of Glasgow, United Kingdom
| | - Zsolt Turi
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, Freiburg, Germany
| | - Yoshikazu Ugawa
- Department of Human Neurophysiology, Fukushima Medical University, Fukushima, Japan
| | | | - Nicole Wenderoth
- Neural Control of Movement Lab, Institute of Human Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland
- Future Health Technologies, Singapore-ETH Centre, Campus for Research Excellence And Technological Enterprise (CREATE), Singapore
| | - Anna Wexler
- Department of Medical Ethics and Health Policy, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, USA
| | - Ulf Ziemann
- Department of Neurology and Stroke, University of Tübingen, Germany
- Hertie Institute for Clinical Brain Research, University of Tübingen, Germany
| | - Walter Paulus
- Department of of Neurology, Ludwig Maximilians University Munich, Germany
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8
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Toward noninvasive brain stimulation 2.0 in Alzheimer's disease. Ageing Res Rev 2022; 75:101555. [PMID: 34973457 PMCID: PMC8858588 DOI: 10.1016/j.arr.2021.101555] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 12/01/2021] [Accepted: 12/27/2021] [Indexed: 12/13/2022]
Abstract
Noninvasive brain stimulation techniques (NiBS) have gathered substantial interest in the study of dementia, considered their possible role in help defining diagnostic biomarkers of altered neural activity for early disease detection and monitoring of its pathophysiological course, as well as for their therapeutic potential of boosting residual cognitive functions. Nevertheless, current approaches suffer from some limitations. In this study, we review and discuss experimental NiBS applications that might help improve the efficacy of future NiBS uses in Alzheimer's Disease (AD), including perturbation-based biomarkers for early diagnosis and disease tracking, solutions to enhance synchronization of oscillatory electroencephalographic activity across brain networks, enhancement of sleep-related memory consolidation, image-guided stimulation for connectome control, protocols targeting interneuron pathology and protein clearance, and finally hybrid-brain models for in-silico modeling of AD pathology and personalized target selection. The present work aims to stress the importance of multidisciplinary, translational, model-driven interventions for precision medicine approaches in AD.
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9
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Asbee J, Parsons TD. Effects of Transcranial Direct Current Stimulation on Cognitive and Affective Outcomes Using Virtual Stimuli: A Systematic Review. CYBERPSYCHOLOGY, BEHAVIOR AND SOCIAL NETWORKING 2021; 24:699-714. [PMID: 33625878 DOI: 10.1089/cyber.2020.0301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Transcranial direct current stimulation (tDCS) is a noninvasive form of brain stimulation used to influence neural activity. While early tDCS studies primarily used static stimuli, there is growing interest in dynamic stimulus presentations using virtual environments (VEs). This review attempts to convey the state of the field. This is not a quantitative meta-analysis as there are not yet enough studies following consistent protocols and/or reporting adequate data. In addition to reviewing the state of the literature, this review includes an exploratory analysis of the available data. Following preferred reporting items for systematic reviews and meta-analyses (PRISMA) guidelines, studies were culled from several databases. Results from this review reveal differences between online and offline stimulation. While offline stimulation did not influence affective and cognitive outcomes, online stimulation led to small changes in affect and cognition. Future studies should include randomized controlled trials with larger samples. Furthermore, greater care needs to be applied to full data reporting (e.g., means, standard deviations, and data for their nonsignificant findings) to improve our understanding of the combined effects of virtual stimuli with tDCS.
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Affiliation(s)
- Justin Asbee
- Department of Psychology, University of North Texas, Denton, Texas, USA
- Computational Neuropsychology & Simulation (CNS) Laboratory, University of North Texas, Denton, Texas, USA
| | - Thomas D Parsons
- Computational Neuropsychology & Simulation (CNS) Laboratory, University of North Texas, Denton, Texas, USA
- College of Information, University of North Texas, Denton, Texas, USA
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10
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Geffen A, Bland N, Sale MV. Effects of Slow Oscillatory Transcranial Alternating Current Stimulation on Motor Cortical Excitability Assessed by Transcranial Magnetic Stimulation. Front Hum Neurosci 2021; 15:726604. [PMID: 34588969 PMCID: PMC8473706 DOI: 10.3389/fnhum.2021.726604] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 08/24/2021] [Indexed: 11/13/2022] Open
Abstract
Converging evidence suggests that transcranial alternating current stimulation (tACS) may entrain endogenous neural oscillations to match the frequency and phase of the exogenously applied current and this entrainment may outlast the stimulation (although only for a few oscillatory cycles following the cessation of stimulation). However, observing entrainment in the electroencephalograph (EEG) during stimulation is extremely difficult due to the presence of complex tACS artifacts. The present study assessed entrainment to slow oscillatory (SO) tACS by measuring motor cortical excitability across different oscillatory phases during (i.e., online) and outlasting (i.e., offline) stimulation. 30 healthy participants received 60 trials of intermittent SO tACS (0.75 Hz; 16 s on/off interleaved) at an intensity of 2 mA peak-to-peak. Motor cortical excitability was assessed using transcranial magnetic stimulation (TMS) of the hand region of the primary motor cortex (M1HAND) to induce motor evoked potentials (MEPs) in the contralateral thumb. MEPs were acquired at four time-points within each trial – early online, late online, early offline, and late offline – as well as at the start and end of the overall stimulation period (to probe longer-lasting aftereffects of tACS). A significant increase in MEP amplitude was observed from pre- to post-tACS (paired-sample t-test; t29 = 2.64, P = 0.013, d = 0.48) and from the first to the last tACS block (t29 = −2.93, P = 0.02, d = 0.54). However, no phase-dependent modulation of excitability was observed. Therefore, although SO tACS had a facilitatory effect on motor cortical excitability that outlasted stimulation, there was no evidence supporting entrainment of endogenous oscillations as the underlying mechanism.
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Affiliation(s)
- Asher Geffen
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Nicholas Bland
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, QLD, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia.,School of Human Movement and Nutrition Sciences, The University of Queensland, St Lucia, QLD, Australia
| | - Martin V Sale
- School of Health and Rehabilitation Sciences, The University of Queensland, St Lucia, QLD, Australia.,Queensland Brain Institute, The University of Queensland, St Lucia, QLD, Australia
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11
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Wafford KA. Aberrant waste disposal in neurodegeneration: why improved sleep could be the solution. CEREBRAL CIRCULATION - COGNITION AND BEHAVIOR 2021; 2:100025. [PMID: 36324713 PMCID: PMC9616228 DOI: 10.1016/j.cccb.2021.100025] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 08/11/2021] [Accepted: 08/12/2021] [Indexed: 06/16/2023]
Abstract
Sleep takes up a large percentage of our lives and the full functions of this state are still not understood. However, over the last 10 years a new and important function has emerged as a mediator of brain clearance. Removal of toxic metabolites and proteins from the brain parenchyma generated during waking activity and high levels of synaptic processing is critical to normal brain function and only enabled during deep sleep. Understanding of this process is revealing how impaired sleep contributes an important and likely causative role in the accumulation and aggregation of aberrant proteins such as β-amyloid and phosphorylated tau, as well as inflammation and neuronal damage. We are also beginning to understand how brain slow-wave activity interacts with vascular function allowing the flow of CSF and interstitial fluid to drain into the body's lymphatic system. New methodology is enabling visualization of this process in both animals and humans and is revealing how these processes break down during ageing and disease. With this understanding we can begin to envisage novel therapeutic approaches to the treatment of neurodegeneration, and how reversing sleep impairment in the correct manner may provide a way to slow these processes and improve brain function.
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Key Words
- AQP4, aquaporin-4
- Alzheimer's disease
- Amyloid
- Aquaporin-4
- Astrocyte
- Aβ, beta amyloid
- BOLD, blood-oxygen level dependent imaging
- CAA, cerebral amyloid angiopathy
- CSF, Cerebrospinal fluid
- Clearance
- EEG, electroencephalography
- EMG, electromyography
- Glymphatic
- ISF, interstitial fluid
- MCI, mild cognitive impairment
- MRI, magnetic resonance imaging
- NOS, nitric oxide synthase
- NREM, non-rapid eye movement
- OSA, obstructive sleep apnea
- PET, positron emission tomography
- REM, rapid-eye movement
- SWA, slow wave activity
- SWS, slow-wave sleep
- Slow-wave sleep
- iNPH, idiopathic normal pressure hydrocephalus
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12
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Martens G, Ibáñez-Soria D, Barra A, Soria-Frisch A, Piarulli A, Gosseries O, Salvador R, Rojas A, Nitsche MA, Kroupi E, Laureys S, Ruffini G, Thibaut A. A novel closed-loop EEG-tDCS approach to promote responsiveness of patients in minimally conscious state: A study protocol. Behav Brain Res 2021; 409:113311. [PMID: 33878429 DOI: 10.1016/j.bbr.2021.113311] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 03/10/2021] [Accepted: 04/15/2021] [Indexed: 01/28/2023]
Abstract
Transcranial direct current stimulation (tDCS) applied over the prefrontal cortex has been shown to improve behavioral responsiveness in patients with disorders of consciousness following severe brain injury, especially those in minimally conscious state (MCS). However, one potential barrier of clinical response to tDCS is the timing of stimulation with regard to the fluctuations of vigilance that characterize this population. Indeed, a previous study showed that the vigilance of MCS patients has periodic average cycles of 70 min (range 57-80 min), potentially preventing them to be in an optimal neural state to benefit from tDCS when applied randomly. To tackle this issue, we propose a new protocol to optimize the application of tDCS by selectively stimulating at high and low vigilance states. Electroencephalography (EEG) real-time spectral entropy will be used as a marker of vigilance and to trigger tDCS, in a closed-loop fashion. We will conduct a randomized controlled crossover clinical trial on 16 patients in prolonged MCS who will undergo three EEG-tDCS sessions 5 days apart (1. tDCS applied at high vigilance; 2. tDCS applied at low vigilance; 3. tDCS applied at a random moment). Behavioral effects will be assessed using the Coma Recovery Scale-Revised at baseline and right after the stimulations. EEG will be recorded throughout the session and for 30 min after the end of the stimulation. This unique and novel approach will provide patients' tailored treatment options, currently lacking in the field of disorders of consciousness.
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Affiliation(s)
- Géraldine Martens
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium; Centre du cerveau², University Hospital of Liège, Liège, Belgium.
| | | | - Alice Barra
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium; Centre du cerveau², University Hospital of Liège, Liège, Belgium
| | | | - Andrea Piarulli
- Department of Surgical, Medical, Molecular and Critical Area Pathology, University of Pisa, Italy
| | - Olivia Gosseries
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium; Centre du cerveau², University Hospital of Liège, Liège, Belgium
| | | | | | - Michael A Nitsche
- Dept. Psychology and Neurosciences, Leibniz Research Centre for Working Environment and Human Factors, Dortmund, Germany; Dept. Neurology, University Medical Hospital Bergmannsheil, Bochum, Germany
| | | | - Steven Laureys
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium; Centre du cerveau², University Hospital of Liège, Liège, Belgium
| | | | - Aurore Thibaut
- Coma Science Group, GIGA Consciousness, University of Liège, Liège, Belgium; Centre du cerveau², University Hospital of Liège, Liège, Belgium
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13
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Stecher HI, Notbohm A, Kasten FH, Herrmann CS. A Comparison of Closed Loop vs. Fixed Frequency tACS on Modulating Brain Oscillations and Visual Detection. Front Hum Neurosci 2021; 15:661432. [PMID: 34248524 PMCID: PMC8261289 DOI: 10.3389/fnhum.2021.661432] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Accepted: 05/03/2021] [Indexed: 12/28/2022] Open
Abstract
Transcranial alternating current stimulation has emerged as an effective tool for the exploration of brain oscillations. By applying a weak alternating current between electrodes placed on the scalp matched to the endogenous frequency, tACS enables the specific modulation of targeted brain oscillations This results in alterations in cognitive functions or persistent physiological changes. Most studies that utilize tACS determine a fixed stimulation frequency prior to the stimulation that is kept constant throughout the experiment. Yet it is known that brain rhythms can encounter shifts in their endogenous frequency. This could potentially move the ongoing brain oscillations into a frequency region where it is no longer affected by the stimulation, thereby decreasing or negating the effect of tACS. Such an effect of a mismatch between stimulation frequency and endogenous frequency on the outcome of stimulation has been shown before for the parietal alpha-activity. In this study, we employed an intermittent closed loop stimulation protocol, where the stimulation is divided into short epochs, between which an EEG is recorded and rapidly analyzed to determine a new stimulation frequency for the next stimulation epoch. This stimulation protocol was tested in a three-group study against a classical fixed stimulation protocol and a sham-treatment. We targeted the parietal alpha rhythm and hypothesized that this setup will ensure a constant close match between the frequencies of tACS and alpha activity. This closer match should lead to an increased modulation of detection of visual luminance changes depending on the phase of the tACS and an increased rise in alpha peak power post stimulation when compared to a protocol with fixed pre-determined stimulation frequency. Contrary to our hypothesis, our results show that only a fixed stimulation protocol leads to a persistent increase in post-stimulation alpha power as compared to sham. Furthermore, in none of the stimulated groups significant modulation of detection performance occurred. While the lack of behavioral effects is inconclusive due to the short selection of different phase bins and trials, the physiological results suggest that a constant stimulation with a fixed frequency is actually beneficial, when the goal is to produce persistent synaptic changes.
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Affiliation(s)
- Heiko I Stecher
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster of Excellence "Hearing4all", Carl von Ossietzky University, Oldenburg, Germany
| | - Annika Notbohm
- Department of Neurological Rehabilitation, Municipal Hospital of Bremen, Bremen, Germany
| | - Florian H Kasten
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster of Excellence "Hearing4all", Carl von Ossietzky University, Oldenburg, Germany
| | - Christoph S Herrmann
- Experimental Psychology Lab, Department of Psychology, European Medical School, Cluster of Excellence "Hearing4all", Carl von Ossietzky University, Oldenburg, Germany.,Research Center Neurosensory Science, Carl von Ossietzky University, Oldenburg, Germany
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14
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Frohlich F, Townsend L. Closed-Loop Transcranial Alternating Current Stimulation: Towards Personalized Non-invasive Brain Stimulation for the Treatment of Psychiatric Illnesses. Curr Behav Neurosci Rep 2021. [DOI: 10.1007/s40473-021-00227-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
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15
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Dondé C, Brunelin J, Micoulaud-Franchi JA, Maruani J, Lejoyeux M, Polosan M, Geoffroy PA. The Effects of Transcranial Electrical Stimulation of the Brain on Sleep: A Systematic Review. Front Psychiatry 2021; 12:646569. [PMID: 34163380 PMCID: PMC8215269 DOI: 10.3389/fpsyt.2021.646569] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2020] [Accepted: 04/19/2021] [Indexed: 01/23/2023] Open
Abstract
Transcranial Electrical Stimulation (tES) is a promising non-invasive brain modulation tool. Over the past years, there have been several attempts to modulate sleep with tES-based approaches in both the healthy and pathological brains. However, data about the impact on measurable aspects of sleep remain scattered between studies, which prevent us from drawing firm conclusions. We conducted a systematic review of studies that explored the impact of tES on neurophysiological sleep oscillations, sleep patterns measured objectively with polysomnography, and subjective psychometric assessments of sleep in both healthy and clinical samples. We searched four main electronic databases to identify studies until February 2020. Forty studies were selected including 511 healthy participants and 452 patients. tES can modify endogenous brain oscillations during sleep. Results concerning changes in sleep patterns are conflicting, whereas subjective assessments show clear improvements after tES. Possible stimulation-induced mechanisms within specific cortico-subcortical sleep structures and networks are discussed. Although these findings cannot be directly transferred to the clinical practice and sleep-enhancing devices development for healthy populations, they might help to pave the way for future researches in these areas. PROSPERO registration number 178910.
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Affiliation(s)
- Clément Dondé
- University Grenoble Alpes, Grenoble, France.,U1216 INSERM, Grenoble Institut of Neuroscience, La Tronche, France.,Psychiatry Department, CHU Grenoble Alpes, Grenoble, France
| | - Jerome Brunelin
- INSERM U1028, CNRS UMR5292, Lyon Neuroscience Research Center, PSY-R2 Team, Lyon, France.,Lyon University, Lyon, France.,Centre Hospitalier le Vinatier, Batiment 416, Bron, France
| | - Jean-Arthur Micoulaud-Franchi
- University Sleep Clinic, Services of Functional Exploration of the Nervous System, University Hospital of Bordeaux, Bordeaux, France.,USR CNRS 3413 SANPSY, University Hospital Pellegrin, University of Bordeaux, Bordeaux, France
| | - Julia Maruani
- Département de Psychiatrie et de Médecine Addictologique, Hôpital Fernand Widal, Assistance Publique des Hôpitaux de Paris (APHP), Paris, France.,Université de Paris, Paris, France.,INSERM U1144, Optimisation Thérapeutique en Neuropsychopharmacologie, Paris, France
| | - Michel Lejoyeux
- Paris Diderot University-Paris VII, 5 Rue Thomas Mann, Paris, France.,University Hospital Bichat-Claude Bernard, 46 rue Henri Huchard, Paris, France
| | - Mircea Polosan
- University Grenoble Alpes, Grenoble, France.,U1216 INSERM, Grenoble Institut of Neuroscience, La Tronche, France.,Psychiatry Department, CHU Grenoble Alpes, Grenoble, France
| | - Pierre A Geoffroy
- Paris Diderot University-Paris VII, 5 Rue Thomas Mann, Paris, France.,University Hospital Bichat-Claude Bernard, 46 rue Henri Huchard, Paris, France.,Université de Paris, NeuroDiderot, Inserm, Paris, France
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16
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Romanella SM, Roe D, Tatti E, Cappon D, Paciorek R, Testani E, Rossi A, Rossi S, Santarnecchi E. The Sleep Side of Aging and Alzheimer's Disease. Sleep Med 2021; 77:209-225. [PMID: 32912799 PMCID: PMC8364256 DOI: 10.1016/j.sleep.2020.05.029] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 05/13/2020] [Accepted: 05/19/2020] [Indexed: 01/23/2023]
Abstract
As we age, sleep patterns undergo significant modifications in micro and macrostructure, worsening cognition and quality of life. These are associated with remarkable brain changes, like deterioration in synaptic plasticity, gray and white matter, and significant modifications in hormone levels. Sleep alterations are also a core component of mild cognitive impairment (MCI) and Alzheimer's Disease (AD). AD night time is characterized by a gradual decrease in slow-wave activity and a substantial reduction of REM sleep. Sleep abnormalities can accelerate AD pathophysiology, promoting the accumulation of amyloid-β (Aβ) and phosphorylated tau. Thus, interventions that target sleep disturbances in elderly people and MCI patients have been suggested as a possible strategy to prevent or decelerate conversion to dementia. Although cognitive-behavioral therapy and pharmacological medications are still first-line treatments, despite being scarcely effective, new interventions have been proposed, such as sensory stimulation and Noninvasive Brain Stimulation (NiBS). The present review outlines the current state of the art of the relationship between sleep modifications in healthy aging and the neurobiological mechanisms underlying age-related changes. Furthermore, we provide a critical analysis showing how sleep abnormalities influence the prognosis of AD pathology by intensifying Aβ and tau protein accumulation. We discuss potential therapeutic strategies to target sleep disruptions and conclude that there is an urgent need for testing new therapeutic sleep interventions.
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Affiliation(s)
- S M Romanella
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy
| | - D Roe
- Beth Israel Deaconess Medical Center, Boston, MA, USA
| | - E Tatti
- Department of Molecular, Cellular & Biomedical Sciences, CUNY, School of Medicine, New York, NY, USA
| | - D Cappon
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - R Paciorek
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
| | - E Testani
- Sleep Medicine Center, Department of Neurology, Policlinico Santa Maria Le Scotte, Siena, Italy
| | - A Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - S Rossi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - E Santarnecchi
- Siena Brain Investigation and Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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17
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Romanella SM, Sprugnoli G, Ruffini G, Seyedmadani K, Rossi S, Santarnecchi E. Noninvasive Brain Stimulation & Space Exploration: Opportunities and Challenges. Neurosci Biobehav Rev 2020; 119:294-319. [PMID: 32937115 PMCID: PMC8361862 DOI: 10.1016/j.neubiorev.2020.09.005] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2020] [Revised: 05/22/2020] [Accepted: 09/03/2020] [Indexed: 01/11/2023]
Abstract
As NASA prepares for longer space missions aiming for the Moon and Mars, astronauts' health and performance are becoming a central concern due to the threats associated with galactic cosmic radiation, unnatural gravity fields, and life in extreme environments. In space, the human brain undergoes functional and structural changes related to fluid shift and changes in intracranial pressure. Behavioral abnormalities, such as cognitive deficits, sleep disruption, and visuomotor difficulties, as well as psychological effects, are also an issue. We discuss opportunities and challenges of noninvasive brain stimulation (NiBS) methods - including transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES) - to support space exploration in several ways. NiBS includes safe and portable techniques already applied in a wide range of cognitive and motor domains, as well as therapeutically. NiBS could be used to enhance in-flight performance, supporting astronauts during pre-flight Earth-based training, as well as to identify biomarkers of post-flight brain changes for optimization of rehabilitation/compensatory strategies. We review these NiBS techniques and their effects on brain physiology, psychology, and cognition.
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Affiliation(s)
- S M Romanella
- Siena Brain Investigation & Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy
| | - G Sprugnoli
- Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA; Radiology Unit, Department of Medicine and Surgery, University of Parma, Parma, Italy
| | - G Ruffini
- Neuroelectrics Corporation, Cambridge, MA, USA
| | - K Seyedmadani
- University Space Research Association NASA Johnson Space Center, Houston, TX, USA; Ann and H.J. Smead Aerospace Engineering Sciences, University of Colorado, Boulder, CO, USA
| | - S Rossi
- Siena Brain Investigation & Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Human Physiology Section, Department of Medicine, Surgery and Neuroscience, University of Siena, Siena, Italy
| | - E Santarnecchi
- Siena Brain Investigation & Neuromodulation Lab (Si-BIN Lab), Department of Medicine, Surgery and Neuroscience, Neurology and Clinical Neurophysiology Section, University of Siena, Italy; Berenson-Allen Center for Noninvasive Brain Stimulation, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA.
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18
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Romanella SM, Roe D, Paciorek R, Cappon D, Ruffini G, Menardi A, Rossi A, Rossi S, Santarnecchi E. Sleep, Noninvasive Brain Stimulation, and the Aging Brain: Challenges and Opportunities. Ageing Res Rev 2020; 61:101067. [PMID: 32380212 DOI: 10.1016/j.arr.2020.101067] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Revised: 02/26/2020] [Accepted: 04/04/2020] [Indexed: 02/06/2023]
Abstract
As we age, sleep patterns undergo severe modifications of their micro and macrostructure, with an overall lighter and more fragmented sleep structure. In general, interventions targeting sleep represent an excellent opportunity not only to maintain life quality in the healthy aging population, but also to enhance cognitive performance and, when pathology arises, to potentially prevent/slow down conversion from e.g. Mild Cognitive Impairment (MCI) to Alzheimer's Disease (AD). Sleep abnormalities are, in fact, one of the earliest recognizable biomarkers of dementia, being also partially responsible for a cascade of cortical events that worsen dementia pathophysiology, including impaired clearance systems leading to build-up of extracellular amyloid-β (Aβ) peptide and intracellular hyperphosphorylated tau proteins. In this context, Noninvasive Brain Stimulation (NiBS) techniques, such as transcranial electrical stimulation (tES) and transcranial magnetic stimulation (TMS), may help investigate the neural substrates of sleep, identify sleep-related pathology biomarkers, and ultimately help patients and healthy elderly individuals to restore sleep quality and cognitive performance. However, brain stimulation applications during sleep have so far not been fully investigated in healthy elderly cohorts, nor tested in AD patients or other related dementias. The manuscript discusses the role of sleep in normal and pathological aging, reviewing available evidence of NiBS applications during both wakefulness and sleep in healthy elderly individuals as well as in MCI/AD patients. Rationale and details for potential future brain stimulation studies targeting sleep alterations in the aging brain are discussed, including enhancement of cognitive performance, overall quality of life as well as protein clearance.
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19
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Neurostimulation techniques to enhance sleep and improve cognition in aging. Neurobiol Dis 2020; 141:104865. [DOI: 10.1016/j.nbd.2020.104865] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Revised: 03/16/2020] [Accepted: 04/02/2020] [Indexed: 01/09/2023] Open
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20
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Fröhlich F, Lustenberger C. Neuromodulation of sleep rhythms in schizophrenia: Towards the rational design of non-invasive brain stimulation. Schizophr Res 2020; 221:71-80. [PMID: 32354662 PMCID: PMC7316586 DOI: 10.1016/j.schres.2020.04.003] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/01/2020] [Accepted: 04/03/2020] [Indexed: 02/01/2023]
Abstract
Brain function critically depends on oscillatory synchronization of neuronal populations both during wake and sleep. Originally, neural oscillations have been discounted as an epiphenomenon. More recently, specific deficits in the structure of brain oscillations have been linked to psychiatric diseases. For example, schizophrenia is hallmarked by abnormalities in different brain oscillations. Key sleep rhythms during NEM sleep such as sleep spindles, which are implicated in memory consolidation and are related to cognitive functions, are strongly diminished in these patients compared to healthy controls. To date, it remains unclear whether these reductions in sleep oscillations are causal for the functional impairments observed in schizophrenia. The application of non-invasive brain stimulation permits the causal examination of brain network dynamics and will help to establish the causal association of sleep oscillations and symptoms of schizophrenia. To accomplish this, stimulation paradigms that selectively engage specific network targets such as sleep spindles or slow waves are needed. We propose that the successful development and application of these non-invasive brain stimulation approaches will require rational design that takes network dynamics and neuroanatomical information into account. The purpose of this article is to prepare the grounds for the next steps towards such rational design of non-invasive stimulation, with a special focus on electrical and auditory stimulation. First, we briefly summarize the deficits in network dynamics during sleep in schizophrenia. Then, we discuss today's and tomorrow's non-invasive brain stimulation modalities to engage these network targets.
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Affiliation(s)
- Flavio Fröhlich
- Department of Psychiatry, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Carolina Center for Neurostimulation, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Neurology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA; Department of Biomedical Engineering, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
| | - Caroline Lustenberger
- Neural Control of Movement Lab, Institute of Movement Sciences and Sport, Department of Health Sciences and Technology, ETH Zurich, 8092 Zurich, Switzerland.
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21
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Salfi F, D'Atri A, Tempesta D, De Gennaro L, Ferrara M. Boosting Slow Oscillations during Sleep to Improve Memory Function in Elderly People: A Review of the Literature. Brain Sci 2020; 10:E300. [PMID: 32429181 PMCID: PMC7287854 DOI: 10.3390/brainsci10050300] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Revised: 05/11/2020] [Accepted: 05/13/2020] [Indexed: 02/05/2023] Open
Abstract
Sleep represents a crucial time window for the consolidation of memory traces. In this view, some brain rhythms play a pivotal role, first of all the sleep slow waves. In particular, the neocortical slow oscillations (SOs), in coordination with the hippocampal ripples and the thalamocortical spindles, support the long-term storage of the declarative memories. The aging brain is characterized by a disruption of this complex system with outcomes on the related cognitive functions. In recent years, the advancement of the comprehension of the sleep-dependent memory consolidation mechanisms has encouraged the development of techniques of SO enhancement during sleep to induce cognitive benefits. In this review, we focused on the studies reporting on the application of acoustic or electric stimulation procedures in order to improve sleep-dependent memory consolidation in older subjects. Although the current literature is limited and presents inconsistencies, there is promising evidence supporting the perspective to non-invasively manipulate the sleeping brain electrophysiology to improve cognition in the elderly, also shedding light on the mechanisms underlying the sleep-memory relations during healthy and pathological aging.
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Affiliation(s)
- Federico Salfi
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Aurora D'Atri
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
| | - Daniela Tempesta
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
| | - Luigi De Gennaro
- Department of Psychology, Sapienza University of Rome, 00185 Rome, Italy
| | - Michele Ferrara
- Department of Biotechnological and Applied Clinical Sciences, University of L'Aquila, 67100 L'Aquila, Italy
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22
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Pilly PK, Skorheim SW, Hubbard RJ, Ketz NA, Roach SM, Lerner I, Jones AP, Robert B, Bryant NB, Hartholt A, Mullins TS, Choe J, Clark VP, Howard MD. One-Shot Tagging During Wake and Cueing During Sleep With Spatiotemporal Patterns of Transcranial Electrical Stimulation Can Boost Long-Term Metamemory of Individual Episodes in Humans. Front Neurosci 2020; 13:1416. [PMID: 31998067 PMCID: PMC6967741 DOI: 10.3389/fnins.2019.01416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 12/16/2019] [Indexed: 12/01/2022] Open
Abstract
Targeted memory reactivation (TMR) during slow-wave oscillations (SWOs) in sleep has been demonstrated with sensory cues to achieve about 5-12% improvement in post-nap memory performance on simple laboratory tasks. But prior work has not yet addressed the one-shot aspect of episodic memory acquisition, or dealt with the presence of interference from ambient environmental cues in real-world settings. Further, TMR with sensory cues may not be scalable to the multitude of experiences over one's lifetime. We designed a novel non-invasive non-sensory paradigm that tags one-shot experiences of minute-long naturalistic episodes in immersive virtual reality (VR) with unique spatiotemporal amplitude-modulated patterns (STAMPs) of transcranial electrical stimulation (tES). In particular, we demonstrated that these STAMPs can be re-applied as brief pulses during SWOs in sleep to achieve about 10-20% improvement in the metamemory of targeted episodes compared to the control episodes at 48 hours after initial viewing. We found that STAMPs can not only facilitate but also impair metamemory for the targeted episodes based on an interaction between pre-sleep metamemory and the number of STAMP applications during sleep. Overnight metamemory improvements were mediated by spectral power increases following the offset of STAMPs in the slow-spindle band (8-12 Hz) for left temporal areas in the scalp electroencephalography (EEG) during sleep. These results prescribe an optimal strategy to leverage STAMPs for boosting metamemory and suggest that real-world episodic memories can be modulated in a targeted manner even with coarser, non-invasive spatiotemporal stimulation.
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Affiliation(s)
- Praveen K. Pilly
- Center for Human-Machine Collaboration, Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA, United States
| | - Steven W. Skorheim
- Center for Human-Machine Collaboration, Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA, United States
| | - Ryan J. Hubbard
- Center for Human-Machine Collaboration, Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA, United States
| | - Nicholas A. Ketz
- Center for Human-Machine Collaboration, Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA, United States
| | - Shane M. Roach
- Center for Human-Machine Collaboration, Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA, United States
| | - Itamar Lerner
- Center of Molecular and Behavior Neuroscience, Rutgers University Newark, Newark, NJ, United States
- Department of Psychology, The University of Texas at San Antonio, San Antonio, TX, United States
| | - Aaron P. Jones
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Bradley Robert
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Natalie B. Bryant
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Arno Hartholt
- Institute for Creative Technologies, University of Southern California, Los Angeles, CA, United States
| | - Teagan S. Mullins
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Jaehoon Choe
- Center for Human-Machine Collaboration, Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA, United States
| | - Vincent P. Clark
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, NM, United States
| | - Michael D. Howard
- Center for Human-Machine Collaboration, Information and Systems Sciences Laboratory, HRL Laboratories, LLC, Malibu, CA, United States
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23
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Marshall L, Cross N, Binder S, Dang-Vu TT. Brain Rhythms During Sleep and Memory Consolidation: Neurobiological Insights. Physiology (Bethesda) 2020; 35:4-15. [DOI: 10.1152/physiol.00004.2019] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Sleep can benefit memory consolidation. The characterization of brain regions underlying memory consolidation during sleep, as well as their temporal interplay, reflected by specific patterns of brain electric activity, is surfacing. Here, we provide an overview of recent concepts and results on the mechanisms of sleep-related memory consolidation. The latest studies strongly impacting future directions of research in this field are highlighted.
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Affiliation(s)
- Lisa Marshall
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Luebeck, Luebeck, Germany
- Center for Brain, Behavior and Metabolism, University of Luebeck, Luebeck, Germany
| | - Nathan Cross
- Perform Center, Center for Studies in Behavioral Neurobiology, and Department of Health, Kinesiology and Applied Physiology, Concordia University, Montreal, Quebec, Canada
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal, CIUSSS Centre-Sud-de-l’Ile-de-Montréal, Montreal, Quebec, Canada
| | - Sonja Binder
- Institute for Experimental and Clinical Pharmacology and Toxicology, University of Luebeck, Luebeck, Germany
- Center for Brain, Behavior and Metabolism, University of Luebeck, Luebeck, Germany
| | - Thien Thanh Dang-Vu
- Perform Center, Center for Studies in Behavioral Neurobiology, and Department of Health, Kinesiology and Applied Physiology, Concordia University, Montreal, Quebec, Canada
- Centre de Recherche de l’Institut Universitaire de Gériatrie de Montréal, CIUSSS Centre-Sud-de-l’Ile-de-Montréal, Montreal, Quebec, Canada
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24
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Raffin E, Salamanca-Giron RF, Hummel FC. Perspectives: Hemianopia-Toward Novel Treatment Options Based on Oscillatory Activity? Neurorehabil Neural Repair 2019; 34:13-25. [PMID: 31858874 DOI: 10.1177/1545968319893286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Stroke has become one of the main causes of visual impairment, with more than 15 million incidences of first-time strokes, per year, worldwide. One-third of stroke survivors exhibit visual impairment, and most of them will not fully recover. Some recovery is possible, but this usually happens in the first few weeks after a stroke. Most of the rehabilitation options that are offered to patients are compensatory, such as optical aids or eye training. However, these techniques do not seem to provide a sufficient amount of improvement transferable to everyday life. Based on the relatively recent idea that the visual system can actually recover from a chronic lesion, visual retraining protocols have emerged, sometimes even in combination with noninvasive brain stimulation (NIBS), to further boost plastic changes in the residual visual tracts and network. The present article reviews the underlying mechanisms supporting visual retraining and describes the first clinical trials that applied NIBS combined with visual retraining. As a further perspective, it gathers the scientific evidence demonstrating the relevance of interregional functional synchronization of brain networks for visual field recovery, especially the causal role of α and γ oscillations in parieto-occipital regions. Because transcranial alternating current stimulation (tACS) can induce frequency-specific entrainment and modulate spike timing-dependent plasticity, we present a new promising interventional approach, consisting of applying physiologically motivated tACS protocols based on multifocal cross-frequency brain stimulation of the visuoattentional network for visual field recovery.
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Affiliation(s)
- Estelle Raffin
- Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland.,Swiss Federal Institute of Technology (EPFL Valais), Sion, Switzerland.,Clinique Romande de Réadaptation, Sion, Switzerland
| | | | - Friedhelm Christoph Hummel
- Swiss Federal Institute of Technology (EPFL), Geneva, Switzerland.,Swiss Federal Institute of Technology (EPFL Valais), Sion, Switzerland.,Clinique Romande de Réadaptation, Sion, Switzerland.,University of Geneva Medical School, Geneva, Switzerland
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25
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Ketz N, Jones AP, Bryant NB, Clark VP, Pilly PK. Closed-Loop Slow-Wave tACS Improves Sleep-Dependent Long-Term Memory Generalization by Modulating Endogenous Oscillations. J Neurosci 2018; 38:7314-7326. [PMID: 30037830 PMCID: PMC6596034 DOI: 10.1523/jneurosci.0273-18.2018] [Citation(s) in RCA: 81] [Impact Index Per Article: 13.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2018] [Revised: 05/31/2018] [Accepted: 06/13/2018] [Indexed: 01/10/2023] Open
Abstract
Benefits in long-term memory retention and generalization have been shown to be related to sleep-dependent processes, which correlate with neural oscillations as measured by changes in electric potential. The specificity and causal role of these oscillations, however, are still poorly understood. Here, we investigated the potential for augmenting endogenous slow-wave (SW) oscillations in humans with closed-loop transcranial alternating current stimulation (tACS) with an aim toward enhancing the consolidation of recent experiences into long-term memory. Sixteen (three female) participants were trained presleep on a target detection task identifying targets hidden in complex visual scenes. During post-training sleep, closed-loop SW detection and stimulation were used to deliver tACS matching the phase and frequency of the dominant oscillation in the range of 0.5-1.2 Hz. Changes in performance were assessed the following day using test images that were identical to the training ("repeated"), and images generated from training scenes but with novel viewpoints ("generalized"). Results showed that active SW tACS during sleep enhanced the postsleep versus presleep target detection accuracy for the generalized images compared with sham nights, while no significant change was found for repeated images. Using a frequency-agnostic clustering approach sensitive to stimulation-induced spectral power changes in scalp EEG, this behavioral enhancement significantly correlated with both a poststimulation increase and a subsequent decrease in measured spectral power within the SW band, which in turn showed increased coupling with spindle amplitude. These results suggest that augmenting endogenous SW oscillations can enhance consolidation by specifically improving generalization over recognition or cued recall.SIGNIFICANCE STATEMENT This human study demonstrates the use of a closed-loop noninvasive brain stimulation method to enhance endogenous neural oscillations during sleep with the effect of improving consolidation of recent experiences into long-term memory. Here we show that transient slow oscillatory transcranial alternating current stimulation (tACS) triggered by endogenous slow oscillations and matching their frequency and phase can increase slow-wave power and coupling with spindles. Further, this increase correlates with overnight improvements in generalization of recent training to facilitate performance in a target detection task. We also provide novel evidence for a tACS-induced refractory period following the tACS-induced increase. Here slow-wave power is temporarily reduced relative to sham stimulation, which nonetheless maintains a positive relationship with behavioral improvements.
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Affiliation(s)
- Nicholas Ketz
- Information and Systems Sciences Laboratory, Center for Human Machine Collaboration, HRL Laboratories, Malibu, California 90265 and
| | - Aaron P Jones
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, New Mexico 87131
| | - Natalie B Bryant
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, New Mexico 87131
| | - Vincent P Clark
- Psychology Clinical Neuroscience Center, Department of Psychology, University of New Mexico, Albuquerque, New Mexico 87131
| | - Praveen K Pilly
- Information and Systems Sciences Laboratory, Center for Human Machine Collaboration, HRL Laboratories, Malibu, California 90265 and
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