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Chittora R, Jain S, Roy A, Pandey S, Kochhar KP. Multifactorial effects of short duration early exposure low intensity magnetic field stimulation in Streptozotocin induced Alzheimer's disease rat model. Neurosci Lett 2024; 836:137878. [PMID: 38862088 DOI: 10.1016/j.neulet.2024.137878] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Revised: 05/17/2024] [Accepted: 06/08/2024] [Indexed: 06/13/2024]
Abstract
Alzheimer's disease (AD) is an approaching, progressive public health crisis which presently lacks an effective treatment. Various non-invasive novel therapies like repetitive transcranial magnetic stimulation have shown potential to improve cognitive performance in AD patients. In the present study, the effect of extremely low intensity magnetic field (MF) stimulation on neurogenesis and cortical electrical activity was explored. Adult Wistar rats were divided into Sham, AD and AD + MF groups. Streptozotocin (STZ) was injected intracerebroventricularly, at a dose of 3 mg/kg body weight for developing AD model. The AD rats were then exposed to MF (17.96 µT) from 8th day of STZ treatment until 15th day, followed by cognitive assessments and electrocortical recording. In brain tissue samples, cresyl violet staining and BrdU immunohistochemistry were done. MF exposure, improved passive avoidance and recognition memory, attenuated neuronal degeneration and enhanced cell proliferation (BrdU positive cells) in comparison to AD rats. It also significantly restores delta wave power from frontal lobe. Our results suggest that early-stage MF exposure could be an asset for AD research and open new avenues in slowing down the progression of Alzheimer's disease.
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Affiliation(s)
- Reena Chittora
- Neurophysiology and Nanomedicine Laboratory, Department of Physiology, AIIMS, New Delhi, India
| | - Suman Jain
- Neurophysiology and Nanomedicine Laboratory, Department of Physiology, AIIMS, New Delhi, India.
| | - Avishek Roy
- Neurophysiology and Nanomedicine Laboratory, Department of Physiology, AIIMS, New Delhi, India; Centre Broca Nouvelle-Aquitaine, Bordeaux, France
| | - Shivam Pandey
- Department of Biostatistics, AIIMS, New Delhi, India
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2
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Park K, Kohl MM, Kwag J. Memory encoding and retrieval by retrosplenial parvalbumin interneurons are impaired in Alzheimer's disease model mice. Curr Biol 2024; 34:434-443.e4. [PMID: 38157861 DOI: 10.1016/j.cub.2023.12.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 10/23/2023] [Accepted: 12/06/2023] [Indexed: 01/03/2024]
Abstract
Memory deficits in Alzheimer's disease (AD) show a strong link with GABAergic interneuron dysfunctions.1,2,3,4,5,6,7 The ensemble dynamics of GABAergic interneurons represent memory encoding and retrieval,8,9,10,11,12 but how GABAergic interneuron dysfunction affects inhibitory ensemble dynamics in AD is unknown. As the retrosplenial cortex (RSC) is critical for episodic memory13,14,15,16 and is affected by β-amyloid accumulation in early AD,17,18,19,20,21 we address this question by performing Ca2+ imaging in RSC parvalbumin (PV)-expressing interneurons during a contextual fear memory task in healthy control mice and the 5XFAD mouse model of AD. We found that populations of PV interneurons responsive to aversive electric foot shocks during contextual fear conditioning (shock-responsive) significantly decreased in the 5XFAD mice, indicating dysfunctions in the recruitment of memory-encoding PV interneurons. In the control mice, ensemble activities of shock-responsive PV interneurons were selectively upregulated during the freezing epoch of the contextual fear memory retrieval, manifested by synaptic potentiation of PV interneuron-mediated inhibition. However, such changes in ensemble dynamics during memory retrieval and synaptic plasticity were both absent in the 5XFAD mice. Optogenetic silencing of PV interneurons during contextual fear conditioning in the control mice mimicked the memory deficits in the 5XFAD mice, while optogenetic activation of PV interneurons in the 5XFAD mice restored memory retrieval. These results demonstrate the critical roles of contextual fear memory-encoding PV interneurons for memory retrieval. Furthermore, synaptic dysfunction of PV interneurons may disrupt the recruitment of PV interneurons and their ensemble dynamics underlying contextual fear memory retrieval, subsequently leading to memory deficits in AD.
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Affiliation(s)
- Kyerl Park
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Korea; Department of Brain and Cognitive Engineering, Korea University, Anam-ro 145, Seongbuk-gu, Seoul 02841, Korea
| | - Michael M Kohl
- School of Psychology and Neuroscience, University of Glasgow, University Avenue, Glasgow G12 8QQ, UK
| | - Jeehyun Kwag
- Department of Brain and Cognitive Sciences, Seoul National University, Gwanak-ro 1, Gwanak-gu, Seoul 08826, Korea.
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3
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Hijazi S, Smit AB, van Kesteren RE. Fast-spiking parvalbumin-positive interneurons in brain physiology and Alzheimer's disease. Mol Psychiatry 2023; 28:4954-4967. [PMID: 37419975 PMCID: PMC11041664 DOI: 10.1038/s41380-023-02168-y] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/18/2023] [Revised: 06/26/2023] [Accepted: 06/26/2023] [Indexed: 07/09/2023]
Abstract
Fast-spiking parvalbumin (PV) interneurons are inhibitory interneurons with unique morphological and functional properties that allow them to precisely control local circuitry, brain networks and memory processing. Since the discovery in 1987 that PV is expressed in a subset of fast-spiking GABAergic inhibitory neurons, our knowledge of the complex molecular and physiological properties of these cells has been expanding. In this review, we highlight the specific properties of PV neurons that allow them to fire at high frequency and with high reliability, enabling them to control network oscillations and shape the encoding, consolidation and retrieval of memories. We next discuss multiple studies reporting PV neuron impairment as a critical step in neuronal network dysfunction and cognitive decline in mouse models of Alzheimer's disease (AD). Finally, we propose potential mechanisms underlying PV neuron dysfunction in AD and we argue that early changes in PV neuron activity could be a causal step in AD-associated network and memory impairment and a significant contributor to disease pathogenesis.
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Affiliation(s)
- Sara Hijazi
- Department of Pharmacology, University of Oxford, Oxford, OX1 3QT, UK
| | - August B Smit
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands
| | - Ronald E van Kesteren
- Department of Molecular and Cellular Neurobiology, Center for Neurogenomics and Cognitive Research, Amsterdam Neuroscience, Vrije Universiteit Amsterdam, 1081 HV, Amsterdam, The Netherlands.
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4
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Olkhova EA, Bradshaw C, Blain A, Alvim D, Turnbull DM, LeBeau FEN, Ng YS, Gorman GS, Lax NZ. A novel mouse model of mitochondrial disease exhibits juvenile-onset severe neurological impairment due to parvalbumin cell mitochondrial dysfunction. Commun Biol 2023; 6:1078. [PMID: 37872380 PMCID: PMC10593770 DOI: 10.1038/s42003-023-05238-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Accepted: 08/10/2023] [Indexed: 10/25/2023] Open
Abstract
Mitochondrial diseases comprise a common group of neurometabolic disorders resulting from OXPHOS defects, that may manifest with neurological impairments, for which there are currently no disease-modifying therapies. Previous studies suggest inhibitory interneuron susceptibility to mitochondrial impairment, especially of parvalbumin-expressing interneurons (PV+). We have developed a mouse model of mitochondrial dysfunction specifically in PV+ cells via conditional Tfam knockout, that exhibited a juvenile-onset progressive phenotype characterised by cognitive deficits, anxiety-like behaviour, head-nodding, stargazing, ataxia, and reduced lifespan. A brain region-dependent decrease of OXPHOS complexes I and IV in PV+ neurons was detected, with Purkinje neurons being most affected. We validated these findings in a neuropathological study of patients with pathogenic mtDNA and POLG variants showing PV+ interneuron loss and deficiencies in complexes I and IV. This mouse model offers a drug screening platform to propel the discovery of therapeutics to treat severe neurological impairment due to mitochondrial dysfunction.
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Affiliation(s)
- Elizaveta A Olkhova
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Carla Bradshaw
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Alasdair Blain
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Debora Alvim
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Doug M Turnbull
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE2 4HH, UK
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Fiona E N LeBeau
- Biosciences Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
| | - Yi Shiau Ng
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE2 4HH, UK
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK
| | - Gráinne S Gorman
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK.
- NHS Highly Specialised Service for Rare Mitochondrial Disorders, Newcastle upon Tyne Hospitals NHS Foundation Trust, Newcastle upon Tyne, NE2 4HH, UK.
- NIHR Newcastle Biomedical Research Centre, Biomedical Research Building, Campus for Ageing and Vitality, Newcastle upon Tyne, NE4 5PL, UK.
| | - Nichola Z Lax
- Wellcome Centre for Mitochondrial Research, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
- Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Framlington Place, Newcastle upon Tyne, NE2 4HH, UK
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5
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Chen Y, Wang X, Xiao B, Luo Z, Long H. Mechanisms and Functions of Activity-Regulated Cytoskeleton-Associated Protein in Synaptic Plasticity. Mol Neurobiol 2023; 60:5738-5754. [PMID: 37338805 DOI: 10.1007/s12035-023-03442-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Accepted: 06/10/2023] [Indexed: 06/21/2023]
Abstract
Activity-regulated cytoskeleton-associated protein (Arc) is one of the most important regulators of cognitive functions in the brain regions. As a hub protein, Arc plays different roles in modulating synaptic plasticity. Arc supports the maintenance of long-term potentiation (LTP) by regulating actin cytoskeletal dynamics, while it guides the endocytosis of AMPAR in long-term depression (LTD). Moreover, Arc can self-assemble into capsids, leading to a new way of communicating among neurons. The transcription and translation of the immediate early gene Arc are rigorous procedures guided by numerous factors, and RNA polymerase II (Pol II) is considered to regulate the precise timing dynamics of gene expression. Since astrocytes can secrete brain-derived neurotrophic factor (BDNF) and L-lactate, their unique roles in Arc expression are emphasized. Here, we review the entire process of Arc expression and summarize the factors that can affect Arc expression and function, including noncoding RNAs, transcription factors, and posttranscriptional regulations. We also attempt to review the functional states and mechanisms of Arc in modulating synaptic plasticity. Furthermore, we discuss the recent progress in understanding the roles of Arc in the occurrence of major neurological disorders and provide new thoughts for future research on Arc.
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Affiliation(s)
- Yifan Chen
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- Xiangya School of Stomatology, Central South University, Changsha, 410008, Hunan, China
| | - Xiaohu Wang
- State Key Laboratory of Cardiovascular Disease, Fuwai Hospital, National Center for Cardiovascular Diseases, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, China
| | - Bo Xiao
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, Hunan, People's Republic of China, 410008
| | - Zhaohui Luo
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, Hunan, People's Republic of China, 410008.
| | - Hongyu Long
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China.
- Clinical Research Center for Epileptic Disease of Hunan Province, Central South University, Changsha, Hunan, People's Republic of China, 410008.
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6
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Yang Y, Ondrejcak T, Hu NW, Islam S, O'Rourke E, Reilly RB, Cunningham C, Rowan MJ, Klyubin I. Gamma-patterned sensory stimulation reverses synaptic plasticity deficits in rat models of early Alzheimer's disease. Eur J Neurosci 2023; 58:3402-3411. [PMID: 37655756 DOI: 10.1111/ejn.16129] [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: 02/05/2023] [Revised: 06/29/2023] [Accepted: 08/09/2023] [Indexed: 09/02/2023]
Abstract
Non-invasive sensory stimulation in the range of the brain's gamma rhythm (30-100 Hz) is emerging as a new potential therapeutic strategy for the treatment of Alzheimer's disease (AD). Here, we investigated the effect of repeated combined exposure to 40 Hz synchronized sound and light stimuli on hippocampal long-term potentiation (LTP) in vivo in three rat models of early AD. We employed a very complete model of AD amyloidosis, amyloid precursor protein (APP)-overexpressing transgenic McGill-R-Thy1-APP rats at an early pre-plaque stage, systemic treatment of transgenic APP rats with corticosterone modelling certain environmental AD risk factors and, importantly, intracerebral injection of highly disease-relevant AD patient-derived synaptotoxic beta-amyloid and tau in wild-type animals. We found that daily treatment with 40 Hz sensory stimulation for 2 weeks fully abrogated the inhibition of LTP in all three models. Moreover, there was a negative correlation between the magnitude of LTP and the level of active caspase-1 in the hippocampus of transgenic APP animals, which suggests that the beneficial effect of 40 Hz stimulation was dependent on modulation of pro-inflammatory mechanisms. Our findings support ongoing clinical trials of gamma-patterned sensory stimulation in early AD.
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Affiliation(s)
- Yin Yang
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Tomas Ondrejcak
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Neng-Wei Hu
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
- Department of Physiology and Neurobiology, School of Basic Medical Sciences, Zhengzhou University, Zhengzhou, China
| | - Sadia Islam
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Eugene O'Rourke
- Department of Electronic and Electrical Engineering, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Richard B Reilly
- School of Medicine, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Colm Cunningham
- School of Biochemistry and Immunology, Trinity Biomedical Sciences Institute, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Michael J Rowan
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
| | - Igor Klyubin
- Department of Pharmacology and Therapeutics, Trinity College Institute of Neuroscience, Trinity College, Dublin 2, Ireland
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7
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Moradi F, van den Berg M, Mirjebreili M, Kosten L, Verhoye M, Amiri M, Keliris GA. Early classification of Alzheimer's disease phenotype based on hippocampal electrophysiology in the TgF344-AD rat model. iScience 2023; 26:107454. [PMID: 37599835 PMCID: PMC10432721 DOI: 10.1016/j.isci.2023.107454] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Revised: 04/27/2023] [Accepted: 07/19/2023] [Indexed: 08/22/2023] Open
Abstract
The hippocampus plays a vital role in navigation, learning, and memory, and is affected in Alzheimer's disease (AD). This study investigated the classification of AD-transgenic rats versus wild-type littermates using electrophysiological activity recorded from the hippocampus at an early, presymptomatic stage of the disease (6 months old) in the TgF344-AD rat model. The recorded signals were filtered into low frequency (LFP) and high frequency (spiking activity) signals, and machine learning classifiers were employed to identify the rat genotype (TG vs. WT). By analyzing specific frequency bands in the low frequency signals and calculating distance metrics between spike trains in the high frequency signals, accurate classification was achieved. Gamma band power emerged as a valuable signal for classification, and combining information from both low and high frequency signals improved the accuracy further. These findings provide valuable insights into the early stage effects of AD on different regions of the hippocampus.
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Affiliation(s)
- Faraz Moradi
- Faculty of Engineering, University of Ottawa, Ottawa, ON, Canada
| | - Monica van den Berg
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | | | - Lauren Kosten
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Marleen Verhoye
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
| | - Mahmood Amiri
- Medical Technology Research Center, Kermanshah University of Medical Sciences, Kermanshah, Iran
| | - Georgios A. Keliris
- Bio-Imaging Lab, University of Antwerp, Antwerp, Belgium
- μNEURO Research Centre of Excellence, University of Antwerp, Antwerp, Belgium
- Institute of Computer Science, Foundation for Research & Technology - Hellas, Heraklion, Crete, Greece
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8
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Adams NE, Jafarian A, Perry A, Rouse MA, Shaw AD, Murley AG, Cope TE, Bevan-Jones WR, Passamonti L, Street D, Holland N, Nesbitt D, Hughes LE, Friston KJ, Rowe JB. Neurophysiological consequences of synapse loss in progressive supranuclear palsy. Brain 2023; 146:2584-2594. [PMID: 36514918 PMCID: PMC10232290 DOI: 10.1093/brain/awac471] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 10/31/2022] [Accepted: 11/08/2022] [Indexed: 12/15/2022] Open
Abstract
Synaptic loss occurs early in many neurodegenerative diseases and contributes to cognitive impairment even in the absence of gross atrophy. Currently, for human disease there are few formal models to explain how cortical networks underlying cognition are affected by synaptic loss. We advocate that biophysical models of neurophysiology offer both a bridge from preclinical to clinical models of pathology and quantitative assays for experimental medicine. Such biophysical models can also disclose hidden neuronal dynamics generating neurophysiological observations such as EEG and magnetoencephalography. Here, we augment a biophysically informed mesoscale model of human cortical function by inclusion of synaptic density estimates as captured by 11C-UCB-J PET, and provide insights into how regional synapse loss affects neurophysiology. We use the primary tauopathy of progressive supranuclear palsy (Richardson's syndrome) as an exemplar condition, with high clinicopathological correlations. Progressive supranuclear palsy causes a marked change in cortical neurophysiology in the presence of mild cortical atrophy and is associated with a decline in cognitive functions associated with the frontal lobe. Using parametric empirical Bayesian inversion of a conductance-based canonical microcircuit model of magnetoencephalography data, we show that the inclusion of regional synaptic density-as a subject-specific prior on laminar-specific neuronal populations-markedly increases model evidence. Specifically, model comparison suggests that a reduction in synaptic density in inferior frontal cortex affects superficial and granular layer glutamatergic excitation. This predicted individual differences in behaviour, demonstrating the link between synaptic loss, neurophysiology and cognitive deficits. The method we demonstrate is not restricted to progressive supranuclear palsy or the effects of synaptic loss: such pathology-enriched dynamic causal models can be used to assess the mechanisms of other neurological disorders, with diverse non-invasive measures of pathology, and is suitable to test the effects of experimental pharmacology.
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Affiliation(s)
- Natalie E Adams
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK
| | - Amirhossein Jafarian
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
| | - Alistair Perry
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK
| | - Matthew A Rouse
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK
| | - Alexander D Shaw
- Washington Singer Laboratories, University of Exeter, Exeter EX4 4QG, UK
| | - Alexander G Murley
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
| | - Thomas E Cope
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK
| | - W Richard Bevan-Jones
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
| | - Luca Passamonti
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK
| | - Duncan Street
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
| | - Negin Holland
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
| | - David Nesbitt
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
| | - Laura E Hughes
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK
| | - Karl J Friston
- Wellcome Centre for Human Neuroimaging, University College London, London WC1N 3AR, UK
| | - James B Rowe
- Department of Clinical Neurosciences and Cambridge University Hospitals NHS Trust, University of Cambridge, Cambridge CB2 0SZ, UK
- MRC Cognition and Brain Sciences Unit, University of Cambridge, Cambridge CB2 7EF, UK
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9
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Victorino DB, Faber J, Pinheiro DJLL, Scorza FA, Almeida ACG, Costa ACS, Scorza CA. Toward the Identification of Neurophysiological Biomarkers for Alzheimer's Disease in Down Syndrome: A Potential Role for Cross-Frequency Phase-Amplitude Coupling Analysis. Aging Dis 2023; 14:428-449. [PMID: 37008053 PMCID: PMC10017148 DOI: 10.14336/ad.2022.0906] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/06/2022] [Indexed: 11/18/2022] Open
Abstract
Cross-frequency coupling (CFC) mechanisms play a central role in brain activity. Pathophysiological mechanisms leading to many brain disorders, such as Alzheimer's disease (AD), may produce unique patterns of brain activity detectable by electroencephalography (EEG). Identifying biomarkers for AD diagnosis is also an ambition among research teams working in Down syndrome (DS), given the increased susceptibility of people with DS to develop early-onset AD (DS-AD). Here, we review accumulating evidence that altered theta-gamma phase-amplitude coupling (PAC) may be one of the earliest EEG signatures of AD, and therefore may serve as an adjuvant tool for detecting cognitive decline in DS-AD. We suggest that this field of research could potentially provide clues to the biophysical mechanisms underlying cognitive dysfunction in DS-AD and generate opportunities for identifying EEG-based biomarkers with diagnostic and prognostic utility in DS-AD.
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Affiliation(s)
- Daniella B Victorino
- Discipline of Neuroscience, Department of Neurology and Neurosurgery, Federal University of São Paulo / Paulista Medical School, São Paulo, SP, Brazil.
| | - Jean Faber
- Discipline of Neuroscience, Department of Neurology and Neurosurgery, Federal University of São Paulo / Paulista Medical School, São Paulo, SP, Brazil.
| | - Daniel J. L. L Pinheiro
- Discipline of Neuroscience, Department of Neurology and Neurosurgery, Federal University of São Paulo / Paulista Medical School, São Paulo, SP, Brazil.
| | - Fulvio A Scorza
- Discipline of Neuroscience, Department of Neurology and Neurosurgery, Federal University of São Paulo / Paulista Medical School, São Paulo, SP, Brazil.
| | - Antônio C. G Almeida
- Department of Biosystems Engineering, Federal University of São João Del Rei, Minas Gerais, MG, Brazil.
| | - Alberto C. S Costa
- Division of Psychiatry, Case Western Reserve University, Cleveland, OH, United States.
- Department of Macromolecular Science and Engineering, Case Western Reserve University, Cleveland, OH, United States.
| | - Carla A Scorza
- Discipline of Neuroscience, Department of Neurology and Neurosurgery, Federal University of São Paulo / Paulista Medical School, São Paulo, SP, Brazil.
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10
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Wang YL, Wang JG, Guo S, Guo FL, Liu EJ, Yang X, Feng B, Wang JZ, Vreugdenhil M, Lu CB. Oligomeric β-Amyloid Suppresses Hippocampal γ-Oscillations through Activation of the mTOR/S6K1 Pathway. Aging Dis 2023:AD.2023.0123. [PMID: 37163441 PMCID: PMC10389838 DOI: 10.14336/ad.2023.0123] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2022] [Accepted: 01/23/2023] [Indexed: 05/12/2023] Open
Abstract
Neuronal synchronization at gamma frequency (30-100 Hz: γ) is impaired in early-stage Alzheimer's disease (AD) patients and AD models. Oligomeric Aβ1-42 caused a concentration-dependent reduction of γ-oscillation strength and regularity while increasing its frequency. The mTOR1 inhibitor rapamycin prevented the Aβ1-42-induced suppression of γ-oscillations, whereas the mTOR activator leucine mimicked the Aβ1-42-induced suppression. Activation of the downstream kinase S6K1, but not inhibition of eIF4E, was required for the Aβ1-42-induced suppression. The involvement of the mTOR/S6K1 signaling in the Aβ1-42-induced suppression was confirmed in Aβ-overexpressing APP/PS1 mice, where inhibiting mTOR or S6K1 restored degraded γ-oscillations. To assess the network changes that may underlie the mTOR/S6K1 mediated γ-oscillation impairment in AD, we tested the effect of Aβ1-42 on IPSCs and EPSCs recorded in pyramidal neurons. Aβ1-42 reduced EPSC amplitude and frequency and IPSC frequency, which could be prevented by inhibiting mTOR or S6K1. These experiments indicate that in early AD, oligomer Aβ1-42 impairs γ-oscillations by reducing inhibitory interneuron activity by activating the mTOR/S6K1 signaling pathway, which may contribute to early cognitive decline and provides new therapeutic targets.
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Affiliation(s)
- Ya-Li Wang
- Department of Physiology and Pathophysiology, Henan International Joint Laboratory of Non-Invasive Neuromodulation, Xinxiang Medical University, Xinxiang, China
| | - Jian-Gang Wang
- Department of Physiology and Pathophysiology, Henan International Joint Laboratory of Non-Invasive Neuromodulation, Xinxiang Medical University, Xinxiang, China
| | - Shuling Guo
- Department of Cardiovascular Medicine, Luminghu District, Xuchang Central Hospital, Xuchang, China
| | - Fang-Li Guo
- Department of Neurology, Anyang District Hospital of Puyang City, Anyang, China
| | - En-Jie Liu
- Department of Pathology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Xin Yang
- Key Laboratory of Translational Research for Brain Diseases, Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen, China
| | - Bingyan Feng
- Department of Physiology and Pathophysiology, Henan International Joint Laboratory of Non-Invasive Neuromodulation, Xinxiang Medical University, Xinxiang, China
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Martin Vreugdenhil
- Department of Life Sciences, Birmingham City University, Birmingham, UK
- Department of Psychology, Xinxiang Medical University, Xinxiang, China
| | - Cheng-Biao Lu
- Department of Physiology and Pathophysiology, Henan International Joint Laboratory of Non-Invasive Neuromodulation, Xinxiang Medical University, Xinxiang, China
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11
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Ko H, Yoon SP. Optogenetic neuromodulation with gamma oscillation as a new strategy for Alzheimer disease: a narrative review. JOURNAL OF YEUNGNAM MEDICAL SCIENCE 2022; 39:269-277. [PMID: 35152662 PMCID: PMC9580057 DOI: 10.12701/jyms.2021.01683] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 01/27/2022] [Accepted: 02/04/2022] [Indexed: 12/31/2022]
Abstract
The amyloid hypothesis has been considered a major explanation of the pathogenesis of Alzheimer disease. However, failure of phase III clinical trials with anti-amyloid-beta monoclonal antibodies reveals the need for other therapeutic approaches to treat Alzheimer disease. Compared to its relatively short history, optogenetics has developed considerably. The expression of microbial opsins in cells using genetic engineering allows specific control of cell signals or molecules. The application of optogenetics to Alzheimer disease research or clinical approaches is increasing. When applied with gamma entrainment, optogenetic neuromodulation can improve Alzheimer disease symptoms. Although safety problems exist with optogenetics such as the use of viral vectors, this technique has great potential for use in Alzheimer disease. In this paper, we review the historical applications of optogenetic neuromodulation with gamma entrainment to investigate the mechanisms involved in Alzheimer disease and potential therapeutic strategies.
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Affiliation(s)
- Haneol Ko
- Medical Course, Jeju National University School of Medicine, Jeju, Korea
| | - Sang-Pil Yoon
- Department of Anatomy, Jeju National University College of Medicine, Jeju, Korea
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12
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Liu Y, Tang C, Wei K, Liu D, Tang K, Chen M, Xia X, Mao Z. Transcranial alternating current stimulation combined with sound stimulation improves the cognitive function of patients with Alzheimer's disease: A case report and literature review. Front Neurol 2022; 13:962684. [PMID: 36212652 PMCID: PMC9539040 DOI: 10.3389/fneur.2022.962684] [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: 06/06/2022] [Accepted: 07/18/2022] [Indexed: 11/13/2022] Open
Abstract
Transcranial alternating current stimulation (tACS) is a relatively new non-invasive brain electrical stimulation method for the treatment of patients with Alzheimer's disease (AD), but it has poor offline effects. Therefore, we applied a new combined stimulation method to observe the offline effect on the cognitive function of patients with AD. Here, we describe the clinical results of a case in which tACS combined with sound stimulation was applied to treat moderate AD. The patient was a 73-year-old woman with a 2-year history of persistent cognitive deterioration despite the administration of Aricept and Sodium Oligomannate. Therefore, the patient received tACS combined with sound stimulation. Her cognitive scale scores improved after 15 sessions and continued to improve at 4 months of follow-up. Although the current report may provide a new alternative therapy for patients with AD, more clinical data are needed to support its efficacy.
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Affiliation(s)
- Yang Liu
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Can Tang
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Kailun Wei
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
| | - Di Liu
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Keke Tang
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Meilian Chen
- Guangzhou Kangzhi Digital Technology Co., Ltd., Guangzhou, China
| | - Xuewei Xia
- Department of Neurosurgery, Affiliated Hospital of Guilin Medical University, Guilin, China
- *Correspondence: Xuewei Xia
| | - Zhiqi Mao
- Department of Neurosurgery, Chinese PLA General Hospital, Beijing, China
- Zhiqi Mao
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13
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Babiloni C. The Dark Side of Alzheimer's Disease: Neglected Physiological Biomarkers of Brain Hyperexcitability and Abnormal Consciousness Level. J Alzheimers Dis 2022; 88:801-807. [PMID: 35754282 DOI: 10.3233/jad-220582] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Affiliation(s)
- Claudio Babiloni
- Department of Physiology and Pharmacology "Vittorio Erspamer", Sapienza University of Rome, Rome, Italy.,Hospital San Raffaele Cassino, Cassino (FR), Italy
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14
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Mackenzie-Gray Scott CA, Pelkey KA, Caccavano AP, Abebe D, Lai M, Black KN, Brown ND, Trevelyan AJ, McBain CJ. Resilient Hippocampal Gamma Rhythmogenesis and Parvalbumin-Expressing Interneuron Function Before and After Plaque Burden in 5xFAD Alzheimer's Disease Model. Front Synaptic Neurosci 2022; 14:857608. [PMID: 35645763 PMCID: PMC9131009 DOI: 10.3389/fnsyn.2022.857608] [Citation(s) in RCA: 6] [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: 01/18/2022] [Accepted: 04/14/2022] [Indexed: 12/04/2022] Open
Abstract
Recent studies have implicated impaired Parvalbumin Fast-Spiking Interneuron (PVIN) function as a precipitating factor underlying abnormalities in network synchrony, oscillatory rhythms, and cognition associated with Alzheimer's disease (AD). However, a complete developmental investigation of potential gamma deficits, induced by commonly used carbachol or kainate in ex vivo slice preparations, within AD model mice is lacking. We examined gamma oscillations using field recordings in acute hippocampal slices from 5xFAD and control mice, through the period of developing pathology, starting at 3 months of age, when there is minimal plaque presence in the hippocampus, through to 12+ months of age, when plaque burden is high. In addition, we examined PVIN participation in gamma rhythms using targeted cell-attached recordings of genetically-reported PVINs, in both wild type and mutant mice. In parallel, a developmental immunohistochemical characterisation probing the PVIN-associated expression of PV and perineuronal nets (PNNs) was compared between control and 5xFAD mice. Remarkably, this comprehensive longitudinal evaluation failed to reveal any obvious correlations between PVIN deficits (electrical and molecular), circuit rhythmogenesis (gamma frequency and power), and Aβ deposits/plaque formation. By 6-12 months, 5xFAD animals have extensive plaque formation throughout the hippocampus. However, a deficit in gamma oscillatory power was only evident in the oldest 5xFAD animals (12+ months), and only when using kainate, and not carbachol, to induce the oscillations. We found no difference in PV firing or phase preference during kainate-induced oscillations in younger or older 5xFAD mice compared to control, and a reduction of PV and PNNs only in the oldest 5xFAD mice. The lack of a clear relationship between PVIN function, network rhythmicity, and plaque formation in our study highlights an unexpected resilience in PVIN function in the face of extensive plaque pathology associated with this model, calling into question the presumptive link between PVIN pathology and Alzheimer's progression.
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Affiliation(s)
- Connie A. Mackenzie-Gray Scott
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
- Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Kenneth A. Pelkey
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Adam P. Caccavano
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Daniel Abebe
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Mandy Lai
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Khayla N. Black
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Nicolette D. Brown
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Andrew J. Trevelyan
- Newcastle University Biosciences Institute, Newcastle University, Newcastle upon Tyne, United Kingdom
| | - Chris J. McBain
- Section on Cellular and Synaptic Physiology, NICHD - Eunice Kennedy Shriver National Institute of Child Health and Human Development, National Institutes of Health (NIH), Bethesda, MD, United States
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15
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Salimi M, Ghazvineh S, Nazari M, Dehdar K, Garousi M, Zare M, Tabasi F, Jamaati H, Salimi A, Barkley V, Mirnajafi-Zadeh J, Raoufy MR. Allergic rhinitis impairs working memory in association with drop of hippocampal - Prefrontal coupling. Brain Res 2021; 1758:147368. [PMID: 33582121 DOI: 10.1016/j.brainres.2021.147368] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2020] [Revised: 01/29/2021] [Accepted: 02/08/2021] [Indexed: 12/18/2022]
Abstract
Allergic rhinitis (AR) is a chronic inflammatory disease frequently associated with a deficit in learning and memory. Working memory is an important system for decision making and guidance, which depends on interactions between the ventral hippocampus (vHipp) and the prelimbic prefrontal cortex (plPFC). It is still unclear whether AR influences the activity and coupling of these brain areas, which consequently may impair working memory. The current study aimed to examine alterations of the vHipp-plPFC circuit in a rat model of AR. Our results show decreased working memory performance in AR animals, accompanied by a reduction of theta and gamma oscillations in plPFC. Also, AR reduces coherence between vHipp and plPFC in both theta and gamma frequency bands. Cross-frequency coupling analyses confirmed a reduced interaction between hippocampal theta and plPFC gamma oscillations. Granger causality analysis revealed a reduction in the causal effects of vHipp activity on plPFC oscillations and vice versa. A significant correlation was found between working memory performance with disruption of functional connectivity in AR animals. In summary, our data show that in AR, there is a deficit of functional coupling between hippocampal and prefrontal network, and suggest that this mechanism might contribute to working memory impairment in individuals with AR.
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Affiliation(s)
- Morteza Salimi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sepideh Ghazvineh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Milad Nazari
- Faculty of Electrical Engineering, Sharif University of Technology, Tehran, Iran
| | - Kolsoum Dehdar
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mani Garousi
- Department of Electrical and Engineering, Tarbiat Modares University, Tehran, Iran
| | - Meysam Zare
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Farhad Tabasi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Hamidreza Jamaati
- Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Alireza Salimi
- Chronic Respiratory Diseases Research Center, National Research Institute of Tuberculosis and Lung Diseases, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Victoria Barkley
- Krembil Research Institute, University Health Network, Toronto, Canada
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Mohammad Reza Raoufy
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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16
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Preparation of Rat Organotypic Hippocampal Slice Cultures Using the Membrane-Interface Method. Methods Mol Biol 2021; 2188:243-257. [PMID: 33119855 DOI: 10.1007/978-1-0716-0818-0_12] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Cultured hippocampal slices from rodents, in which the architecture and functional properties of the hippocampal network are largely preserved, have proved to be a powerful substrate for studying healthy and pathological neuronal mechanisms. Here, we delineate the membrane-interface method for maintaining organotypic slices in culture for several weeks. The protocol includes procedures for dissecting hippocampus from rat brain, and collecting slices using a vibratome. This method provides the experimenter with easy access to both the brain tissue and culture medium, which facilitates genetic and pharmacological manipulations and enables experiments that incorporate imaging and electrophysiology. The method is generally applicable to rats of different ages, and to different brain regions, and can be modified for culture of slices from other species including mice.
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17
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Acute Effects of Two Different Species of Amyloid- β on Oscillatory Activity and Synaptic Plasticity in the Commissural CA3-CA1 Circuit of the Hippocampus. Neural Plast 2021; 2020:8869526. [PMID: 33381164 PMCID: PMC7765721 DOI: 10.1155/2020/8869526] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 12/04/2020] [Accepted: 12/08/2020] [Indexed: 11/29/2022] Open
Abstract
Recent evidence indicates that soluble amyloid-β (Aβ) species induce imbalances in excitatory and inhibitory transmission, resulting in neural network functional impairment and cognitive deficits during early stages of Alzheimer's disease (AD). To evaluate the in vivo effects of two soluble Aβ species (Aβ25-35 and Aβ1-40) on commissural CA3-to-CA1 (cCA3-to-CA1) synaptic transmission and plasticity, and CA1 oscillatory activity, we used acute intrahippocampal microinjections in adult anaesthetized male Wistar rats. Soluble Aβ microinjection increased cCA3-to-CA1 synaptic variability without significant changes in synaptic efficiency. High-frequency CA3 stimulation was rendered inefficient by soluble Aβ intrahippocampal injection to induce long-term potentiation and to enhance synaptic variability in CA1, contrasting with what was observed in vehicle-injected subjects. Although soluble Aβ microinjection significantly increased the relative power of γ-band and ripple oscillations and significantly shifted the average vector of θ-to-γ phase-amplitude coupling (PAC) in CA1, it prevented θ-to-γ PAC shift induced by high-frequency CA3 stimulation, opposite to what was observed in vehicle-injected animals. These results provide further evidence that soluble Aβ species induce synaptic dysfunction causing abnormal synaptic variability, impaired long-term plasticity, and deviant oscillatory activity, leading to network activity derailment in the hippocampus.
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18
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Fielder E, Tweedy C, Wilson C, Oakley F, LeBeau FEN, Passos JF, Mann DA, von Zglinicki T, Jurk D. Anti-inflammatory treatment rescues memory deficits during aging in nfkb1 -/- mice. Aging Cell 2020; 19:e13188. [PMID: 32915495 PMCID: PMC7576267 DOI: 10.1111/acel.13188] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2020] [Revised: 05/29/2020] [Accepted: 06/14/2020] [Indexed: 12/11/2022] Open
Abstract
Chronic inflammation is a common feature of many age-related conditions including neurodegenerative diseases such as Alzheimer's disease. Cellular senescence is a state of irreversible cell-cycle arrest, thought to contribute to neurodegenerative diseases partially via induction of a chronic pro-inflammatory phenotype. In this study, we used a mouse model of genetically enhanced NF-κB activity (nfκb1-/- ), characterized by low-grade chronic inflammation and premature aging, to investigate the impact of inflammaging on cognitive decline. We found that during aging, nfkb1-/- mice show an early onset of memory loss, combined with enhanced neuroinflammation and increased frequency of senescent cells in the hippocampus and cerebellum. Electrophysiological measurements in the hippocampus of nfkb1-/- mice in vitro revealed deficits in gamma frequency oscillations, which could explain the decline in memory capacity. Importantly, treatment with the nonsteroidal anti-inflammatory drug (NASID) ibuprofen reduced neuroinflammation and senescent cell burden resulting in significant improvements in cognitive function and gamma frequency oscillations. These data support the hypothesis that chronic inflammation is a causal factor in the cognitive decline observed during aging.
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Affiliation(s)
- Edward Fielder
- Biosciences InstituteAgeing Research LaboratoriesCampus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
| | - Clare Tweedy
- Biosciences InstituteFaculty of Medical SciencesNewcastle UniversityNewcastleUK
| | - Caroline Wilson
- Bioscience InstituteImmunity and InflammationNewcastle Fibrosis Research GroupFaculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Fiona Oakley
- Bioscience InstituteImmunity and InflammationNewcastle Fibrosis Research GroupFaculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Fiona E. N. LeBeau
- Biosciences InstituteFaculty of Medical SciencesNewcastle UniversityNewcastleUK
| | - João F. Passos
- Robert and Arlene Kogod Center on AgingMayo ClinicRochesterMNUSA
- Department of Physiology and Biomedical EngineeringMayo ClinicRochesterMNUSA
| | - Derek A. Mann
- Bioscience InstituteImmunity and InflammationNewcastle Fibrosis Research GroupFaculty of Medical SciencesNewcastle UniversityNewcastle upon TyneUK
| | - Thomas von Zglinicki
- Biosciences InstituteAgeing Research LaboratoriesCampus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
| | - Diana Jurk
- Biosciences InstituteAgeing Research LaboratoriesCampus for Ageing and VitalityNewcastle UniversityNewcastle upon TyneUK
- Robert and Arlene Kogod Center on AgingMayo ClinicRochesterMNUSA
- Department of Physiology and Biomedical EngineeringMayo ClinicRochesterMNUSA
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19
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Xing Y, Wei P, Wang C, Shan Y, Yu Y, Qiao Y, Xie B, Shi X, Zhu Z, Lu J, Zhao G, Jia J, Tang Y. TRanscranial AlterNating current Stimulation FOR patients with Mild Alzheimer's Disease (TRANSFORM-AD study): Protocol for a randomized controlled clinical trial. ALZHEIMERS & DEMENTIA-TRANSLATIONAL RESEARCH & CLINICAL INTERVENTIONS 2020; 6:e12005. [PMID: 32313830 PMCID: PMC7158579 DOI: 10.1002/trc2.12005] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/19/2019] [Accepted: 12/26/2019] [Indexed: 12/20/2022]
Abstract
Introduction Recently, transcranial alternating current stimulation (tACS), which can interact with ongoing neuronal activity, has emerged as a potentially effective and promising treatment for Alzheimer's disease (AD), and the 40 Hz gamma frequency was suggested as a suitable stimulation frequency for AD. Methods The TRANSFORM‐AD study is a double‐blind, randomized‐controlled trial that will include 40 individuals with mild AD. Eligible patients need to have amyloid β (Aβ) loads examined by Pittsburgh compound B (PiB) positron emission tomography (PET) or decreased Aβ level in cerebrospinal fluid. Participants will be randomized into either a 40 Hz tACS group or a sham stimulation group. Both groups will undergo 30 one‐hour sessions across 3 weeks (21 days). The outcome measures will be assessed at baseline, at the end of the intervention, and 3 months after the first session. The primary outcome is global cognitive function, assessed by the 11‐item cognitive subscale of the Alzheimer's Disease Assessment Scale (ADAS‐Cog), and the secondary outcomes include changes in other neuropsychological assessments and in PiB‐PET, structural magnetic resonance imaging (MRI), resting electroencephalography (EEG), and simultaneous EEG–functional MRI (EEG‐fMRI) results. Results The trial is currently ongoing, and it is anticipated that recruitment will be completed in June 2021. Discussion This trial will evaluate the efficacy and safety of 40 Hz tACS in patients with AD, and further explore the potential mechanisms by analyzing amyloid deposits using PiB‐PET, brain volume and white matter integrity by structural MRI, and neural activity by EEG and EEG‐fMRI.
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Affiliation(s)
- Yi Xing
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China.,Key Laboratory of Neurodegenerative Diseases Ministry of Education of the People's Republic of China Beijing China
| | - Penghu Wei
- Department of Neurosurgery Xuanwu Hospital Capital Medical University Beijing China
| | - Changming Wang
- Department of Neurosurgery Xuanwu Hospital Capital Medical University Beijing China
| | - Yi Shan
- Department of Radiology Xuanwu Hospital Capital Medical University Beijing China
| | - Yueying Yu
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China.,Key Laboratory of Neurodegenerative Diseases Ministry of Education of the People's Republic of China Beijing China
| | - Yuchen Qiao
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China.,Key Laboratory of Neurodegenerative Diseases Ministry of Education of the People's Republic of China Beijing China
| | - Beijia Xie
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China.,Key Laboratory of Neurodegenerative Diseases Ministry of Education of the People's Republic of China Beijing China
| | - Xinrui Shi
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China.,Key Laboratory of Neurodegenerative Diseases Ministry of Education of the People's Republic of China Beijing China
| | - Zhongfang Zhu
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China
| | - Jie Lu
- Department of Radiology Xuanwu Hospital Capital Medical University Beijing China
| | - Guoguang Zhao
- Department of Neurosurgery Xuanwu Hospital Capital Medical University Beijing China
| | - Jianping Jia
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China.,Key Laboratory of Neurodegenerative Diseases Ministry of Education of the People's Republic of China Beijing China
| | - Yi Tang
- Innovation Center for Neurological Disorders Department of Neurology, Xuanwu Hospital Capital Medical University National Clinical Research Center for Geriatric Diseases Beijing China.,Key Laboratory of Neurodegenerative Diseases Ministry of Education of the People's Republic of China Beijing China
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20
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Dissociation of somatostatin and parvalbumin interneurons circuit dysfunctions underlying hippocampal theta and gamma oscillations impaired by amyloid β oligomers in vivo. Brain Struct Funct 2020; 225:935-954. [PMID: 32107637 PMCID: PMC7166204 DOI: 10.1007/s00429-020-02044-3] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Accepted: 02/06/2020] [Indexed: 12/18/2022]
Abstract
Accumulation of amyloid β oligomers (AβO) in Alzheimer’s disease (AD) impairs hippocampal theta and gamma oscillations. These oscillations are important in memory functions and depend on distinct subtypes of hippocampal interneurons such as somatostatin-positive (SST) and parvalbumin-positive (PV) interneurons. Here, we investigated whether AβO causes dysfunctions in SST and PV interneurons by optogenetically manipulating them during theta and gamma oscillations in vivo in AβO-injected SST-Cre or PV-Cre mice. Hippocampal in vivo multi-electrode recordings revealed that optogenetic activation of channelrhodopsin-2 (ChR2)-expressing SST and PV interneurons in AβO-injected mice selectively restored AβO-induced reduction of the peak power of theta and gamma oscillations, respectively, and resynchronized CA1 pyramidal cell (PC) spikes. Moreover, SST and PV interneuron spike phases were resynchronized relative to theta and gamma oscillations, respectively. Whole-cell voltage-clamp recordings in CA1 PC in ex vivo hippocampal slices from AβO-injected mice revealed that optogenetic activation of SST and PV interneurons enhanced spontaneous inhibitory postsynaptic currents (IPSCs) selectively at theta and gamma frequencies, respectively. Furthermore, analyses of the stimulus–response curve, paired-pulse ratio, and short-term plasticity of SST and PV interneuron-evoked IPSCs ex vivo showed that AβO increased the initial GABA release probability to depress SST/PV interneuron’s inhibitory input to CA1 PC selectively at theta and gamma frequencies, respectively. Our results reveal frequency-specific and interneuron subtype-specific presynaptic dysfunctions of SST and PV interneurons’ input to CA1 PC as the synaptic mechanisms underlying AβO-induced impairments of hippocampal network oscillations and identify them as potential therapeutic targets for restoring hippocampal network oscillations in early AD.
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21
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Peña-Ortega F. Brain Arrhythmias Induced by Amyloid Beta and Inflammation: Involvement in Alzheimer’s Disease and Other Inflammation-related Pathologies. Curr Alzheimer Res 2020; 16:1108-1131. [DOI: 10.2174/1567205017666191213162233] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2019] [Revised: 10/29/2019] [Accepted: 11/05/2019] [Indexed: 12/13/2022]
Abstract
A variety of neurological diseases, including Alzheimer’s disease (AD), involve amyloid beta (Aβ) accumulation and/or neuroinflammation, which can alter synaptic and neural circuit functions. Consequently, these pathological conditions induce changes in neural network rhythmic activity (brain arrhythmias), which affects many brain functions. Neural network rhythms are involved in information processing, storage and retrieval, which are essential for memory consolidation, executive functioning and sensory processing. Therefore, brain arrhythmias could have catastrophic effects on circuit function, underlying the symptoms of various neurological diseases. Moreover, brain arrhythmias can serve as biomarkers for a variety of brain diseases. The aim of this review is to provide evidence linking Aβ and inflammation to neural network dysfunction, focusing on alterations in brain rhythms and their impact on cognition and sensory processing. I reviewed the most common brain arrhythmias characterized in AD, in AD transgenic models and those induced by Aβ. In addition, I reviewed the modulations of brain rhythms in neuroinflammatory diseases and those induced by immunogens, interleukins and microglia. This review reveals that Aβ and inflammation produce a complex set of effects on neural network function, which are related to the induction of brain arrhythmias and hyperexcitability, both closely related to behavioral alterations. Understanding these brain arrhythmias can help to develop therapeutic strategies to halt or prevent these neural network alterations and treat not only the arrhythmias but also the symptoms of AD and other inflammation-related pathologies.
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Affiliation(s)
- Fernando Peña-Ortega
- Departamento de Neurobiologia del Desarrollo y Neurofisiologia, Instituto de Neurobiologia, Universidad Nacional Autonoma de Mexico, Queretaro, Qro., 76230, Mexico
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What electrophysiology tells us about Alzheimer's disease: a window into the synchronization and connectivity of brain neurons. Neurobiol Aging 2020; 85:58-73. [DOI: 10.1016/j.neurobiolaging.2019.09.008] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 08/27/2019] [Accepted: 09/14/2019] [Indexed: 01/14/2023]
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Pervolaraki E, Hall SP, Foresteire D, Saito T, Saido TC, Whittington MA, Lever C, Dachtler J. Insoluble Aβ overexpression in an App knock-in mouse model alters microstructure and gamma oscillations in the prefrontal cortex, affecting anxiety-related behaviours. Dis Model Mech 2019; 12:dmm040550. [PMID: 31439589 PMCID: PMC6765200 DOI: 10.1242/dmm.040550] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2019] [Accepted: 08/15/2019] [Indexed: 12/31/2022] Open
Abstract
We studied a new amyloid-beta precursor protein (App) knock-in mouse model of Alzheimer's disease (AppNL-G-F ), containing the Swedish KM670/671NL mutation, the Iberian I716F mutation and the Artic E693G mutation, which generates elevated levels of amyloid beta (Aβ)40 and Aβ42 without the confounds associated with APP overexpression. This enabled us to assess changes in anxiety-related and social behaviours, and neural alterations potentially underlying such changes, driven specifically by Aβ accumulation. AppNL-G-F knock-in mice exhibited subtle deficits in tasks assessing social olfaction, but not in social motivation tasks. In anxiety-assessing tasks, AppNL-G-F knock-in mice exhibited: (1) increased thigmotaxis in the open field (OF), yet; (2) reduced closed-arm, and increased open-arm, time in the elevated plus maze (EPM). Their ostensibly anxiogenic OF profile, yet ostensibly anxiolytic EPM profile, could hint at altered cortical mechanisms affecting decision-making (e.g. 'disinhibition'), rather than simple core deficits in emotional motivation. Consistent with this possibility, alterations in microstructure, glutamatergic-dependent gamma oscillations and glutamatergic gene expression were all observed in the prefrontal cortex, but not the amygdala, of AppNL-G-F knock-in mice. Thus, insoluble Aβ overexpression drives prefrontal cortical alterations, potentially underlying changes in social and anxiety-related behavioural tasks.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
| | - Stephen P Hall
- Hull York Medical School, University of York, Heslington, YO10 5DD, UK
| | - Denise Foresteire
- Department of Psychology, Durham University, South Road, Durham, DH1 3LE, UK
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | | | - Colin Lever
- Department of Psychology, Durham University, South Road, Durham, DH1 3LE, UK
| | - James Dachtler
- Department of Psychology, Durham University, South Road, Durham, DH1 3LE, UK
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Early alterations in hippocampal perisomatic GABAergic synapses and network oscillations in a mouse model of Alzheimer's disease amyloidosis. PLoS One 2019; 14:e0209228. [PMID: 30645585 PMCID: PMC6333398 DOI: 10.1371/journal.pone.0209228] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2018] [Accepted: 11/30/2018] [Indexed: 01/01/2023] Open
Abstract
Several lines of evidence imply changes in inhibitory interneuron connectivity and subsequent alterations in oscillatory network activities in the pathogenesis of Alzheimer’s Disease (AD). Recently, we provided evidence for an increased immunoreactivity of both the postsynaptic scaffold protein gephyrin and the GABAA receptor γ2-subunit in the hippocampus of young (1 and 3 months of age), APPPS1 mice. These mice represent a well-established model of cerebral amyloidosis, which is a hallmark of human AD. In this study, we demonstrate a robust increase of parvalbumin immunoreactivity and accentuated projections of parvalbumin positive (PV+) interneurons, which target perisomatic regions of pyramidal cells within the hippocampal subregions CA1 and CA3 of 3-month-old APPPS1 mice. Colocalisation studies confirmed a significant increase in the density of PV+ projections labeled with antibodies against a presynaptic (vesicular GABA transporter) and a postsynaptic marker (gephyrin) of inhibitory synapses within the pyramidal cell layer of CA1 and CA3. As perisomatic inhibition by PV+-interneurons is crucial for the generation of hippocampal network oscillations involved in spatial processing, learning and memory formation we investigated the impact of the putative enhanced perisomatic inhibition on two types of fast neuronal network oscillations in acute hippocampal slices: 1. spontaneously occurring sharp wave-ripple complexes (SPW-R), and 2. cholinergic γ-oscillations. Interestingly, both network patterns were generally preserved in APPPS1 mice similar to WT mice. However, the comparison of simultaneous CA3 and CA1 recordings revealed that the incidence and amplitude of SPW-Rs were significantly lower in CA1 vs CA3 in APPPS1 slices, whereas the power of γ-oscillations was significantly higher in CA3 vs CA1 in WT-slices indicating an impaired communication between the CA3 and CA1 network activities in APPPS1 mice. Taken together, our data demonstrate an increased GABAergic synaptic output of PV+ interneurons impinging on pyramidal cells of CA1 and CA3, which might limit the coordinated cross-talk between these two hippocampal areas in young APPPS1 mice and mediate long-term changes in synaptic inhibition during progression of amyloidosis.
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Balleza-Tapia H, Crux S, Andrade-Talavera Y, Dolz-Gaiton P, Papadia D, Chen G, Johansson J, Fisahn A. TrpV1 receptor activation rescues neuronal function and network gamma oscillations from Aβ-induced impairment in mouse hippocampus in vitro. eLife 2018; 7:37703. [PMID: 30417826 PMCID: PMC6281315 DOI: 10.7554/elife.37703] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 11/08/2018] [Indexed: 12/24/2022] Open
Abstract
Amyloid-β peptide (Aβ) forms plaques in Alzheimer’s disease (AD) and is responsible for early cognitive deficits in AD patients. Advancing cognitive decline is accompanied by progressive impairment of cognition-relevant EEG patterns such as gamma oscillations. The endocannabinoid anandamide, a TrpV1-receptor agonist, reverses hippocampal damage and memory impairment in rodents and protects neurons from Aβ-induced cytotoxic effects. Here, we investigate a restorative role of TrpV1-receptor activation against Aβ-induced degradation of hippocampal neuron function and gamma oscillations. We found that the TrpV1-receptor agonist capsaicin rescues Aβ-induced degradation of hippocampal gamma oscillations by reversing both the desynchronization of AP firing in CA3 pyramidal cells and the shift in excitatory/inhibitory current balance. This rescue effect is TrpV1-receptor-dependent since it was absent in TrpV1 knockout mice or in the presence of the TrpV1-receptor antagonist capsazepine. Our findings provide novel insight into the network mechanisms underlying cognitive decline in AD and suggest TrpV1 activation as a novel therapeutic target.
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Affiliation(s)
- Hugo Balleza-Tapia
- Neuronal Oscillations Laboratory, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden
| | - Sophie Crux
- Neuronal Oscillations Laboratory, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden.,German Center for Neurodegenerative Diseases, Munich, Germany
| | - Yuniesky Andrade-Talavera
- Neuronal Oscillations Laboratory, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden
| | - Pablo Dolz-Gaiton
- Neuronal Oscillations Laboratory, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden
| | - Daniela Papadia
- Neuronal Oscillations Laboratory, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden
| | - Gefei Chen
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden
| | - Jan Johansson
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden
| | - André Fisahn
- Neuronal Oscillations Laboratory, Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Neurogeriatrics Division, Karolinska Institutet, Stockholm, Sweden
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Zallo F, Gardenal E, Verkhratsky A, Rodríguez JJ. Loss of calretinin and parvalbumin positive interneurones in the hippocampal CA1 of aged Alzheimer's disease mice. Neurosci Lett 2018; 681:19-25. [PMID: 29782955 DOI: 10.1016/j.neulet.2018.05.027] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2017] [Revised: 04/30/2018] [Accepted: 05/17/2018] [Indexed: 01/19/2023]
Abstract
Neuronal degeneration associated with Alzheimer's disease (AD), is linked to impaired calcium homeostasis and to changes in calcium-binding proteins (CBPs). The AD-related modification of neuronal CBPs remains controversial. Here we analysed the presence and expression of calretinin (CR) and parvalbumin (PV) in the hippocampal CA1 neurones of 18 months old 3xTg-AD mice compared to non-Tg animals. We found a layer specific decrease in number of interneurones expressing CR and PV (by 33.7% and 52%, respectively). Expression of PV decreased (by 13.8%) in PV-positive neurones, whereas expression of CR did not change in CR positive cells. The loss of specific subpopulations of Ca2+-binding proteins expressing interneurones (CR and PV) together with the decrease of PV in the surviving cells may be linked to their vulnerability to AD pathology. Specific loss of inhibitory interneurones with age could contribute to overall increase in the network excitability associated with AD.
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Affiliation(s)
- Fatima Zallo
- BioCruces Health Research Institute, 48903, Barakaldo, Spain; Department of Neuroscience, University of the Basque Country UPV/EHU, 48940, Leioa, Spain
| | - Emanuela Gardenal
- Department of Neuroscience, University of the Basque Country UPV/EHU, 48940, Leioa, Spain; Human Histology and Embryology Unit, Medical School, University of Verona, 37134, Verona, Italy
| | - Alexei Verkhratsky
- Department of Neuroscience, University of the Basque Country UPV/EHU, 48940, Leioa, Spain; IKERBASQUE, Basque Foundation for Science, 48013-Bilbao, Medical School, Spain; Achúcarro Basque Center for Neuroscience, 48940, Leioa, Spain; Faculty of Biology, Medicine and Health, The University of Manchester, Manchester, M13 9PL, United Kingdom; Center for Basic and Translational Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, 2200, Denmark
| | - José Julio Rodríguez
- BioCruces Health Research Institute, 48903, Barakaldo, Spain; Department of Neuroscience, University of the Basque Country UPV/EHU, 48940, Leioa, Spain; IKERBASQUE, Basque Foundation for Science, 48013-Bilbao, Medical School, Spain.
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Robson E, Tweedy C, Manzanza N, Taylor JP, Atkinson P, Randall F, Reeve A, Clowry GJ, LeBeau FEN. Impaired Fast Network Oscillations and Mitochondrial Dysfunction in a Mouse Model of Alpha-synucleinopathy (A30P). Neuroscience 2018. [PMID: 29524634 DOI: 10.1016/j.neuroscience.2018.02.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Intracellular accumulation of alpha-synuclein (α-syn) is a key pathological process evident in Lewy body dementias (LBDs), including Parkinson's disease dementia (PDD) and dementia with Lewy bodies (DLB). LBD results in marked cognitive impairments and changes in cortical networks. To assess the impact of abnormal α-syn expression on cortical network oscillations relevant to cognitive function, we studied changes in fast beta/gamma network oscillations in the hippocampus in a mouse line that over-expresses human mutant α-syn (A30P). We found an age-dependent reduction in the power of the gamma (20-80 Hz) frequency oscillations in slices taken from mice aged 9-16 months (9+A30P), that was not present in either young 2-6 months old (2+A30P) mice, or in control mice at either age. The mitochondrial blockers potassium cyanide and rotenone both reduced network oscillations in a concentration-dependent manner in aged A30P mice and aged control mice but slices from A30P mice showed a greater reduction in the oscillations. Histochemical analysis showed an age-dependent reduction in cytochrome c oxidase (COX) activity, suggesting a mitochondrial dysfunction in the 9+A30P group. A deficit in COX IV expression was confirmed by immunohistochemistry. Overall, our data demonstrate an age-dependent impairment in mitochondrial function and gamma frequency activity associated with the abnormal expression of α-syn. These findings provide mechanistic insights into the consequences of over-expression of α-syn which might contribute to cognitive decline.
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Affiliation(s)
- Emma Robson
- Institute of Neuroscience, Newcastle University, Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK
| | - Clare Tweedy
- Institute of Neuroscience, Newcastle University, Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK
| | - Nelson Manzanza
- Institute of Neuroscience, Newcastle University, Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK
| | - John-Paul Taylor
- Institute of Neuroscience, Newcastle University, Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK
| | - Peter Atkinson
- Eisai Hatfield Research Laboratories, Eisai Ltd., European Knowledge Centre, Mosquito Way, Hatfield, Herts AL10 9SN, UK
| | - Fiona Randall
- Eisai AiM Institute, Eisai Inc., 4 Corporate Drive, Andover, MA 01810, USA
| | - Amy Reeve
- Institute of Neuroscience, Newcastle University, Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK
| | - Gavin J Clowry
- Institute of Neuroscience, Newcastle University, Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK
| | - Fiona E N LeBeau
- Institute of Neuroscience, Newcastle University, Medical School, Framlington Place, Newcastle-upon-Tyne, NE2 4HH, UK.
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28
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Wang HL, Xian XH, Song QY, Pang C, Wang JL, Wang MW, Li WB. Age-related alterations of neuronal excitability and voltage-dependent Ca 2+ current in a spontaneous mouse model of Alzheimer's disease. Behav Brain Res 2017; 321:209-213. [PMID: 28069411 DOI: 10.1016/j.bbr.2017.01.009] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Revised: 01/02/2017] [Accepted: 01/04/2017] [Indexed: 12/13/2022]
Abstract
Alzheimer's disease (AD) is the most common age-dependent neurodegenerative disorder, characterized by a progressive dysfunction of central neurons, and senescence-accelerated mouse prone 8 (SAMP8), a spontaneous AD mouse model, appears to be an excellent model to investigate the process of AD. Previous studies have indicated that neuronal excitability is impaired in transgenic AD mice. In this study, the cognition of SAMP8 mice was tested using the passive avoidance task and Morris water maze; whole-cell current-clamp recordings were used to evaluate the neuronal excitability, including the resting membrane potential, the number of action potentials, and after-hyperpolarization; and the voltage-dependent Ca2+ current in hippocampal slices was measured using whole-cell voltage-clamp recordings. We found that compared to the young mice, the performance in the learning and memory behavior tasks was impaired in aged mice, and the hippocampal CA1 pyramidal neurons of the aged mice showed a significantly depolarized resting membrane potential, increased numbers of action potentials after injection of depolarizing current, and increased after-hyperpolarization after the action potentials. Consistent with the above changes, the voltage-dependent Ca2+ current was larger in aged mice than in young mice. These data suggested that the aged SAMP8 neurons were hyperexcitable, and the alterations in the voltage-dependent Ca2+ current of aged neurons occurred in parallel to the elevation in excitability.
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Affiliation(s)
- Hua-Long Wang
- Department of Neurology, The First Hospital of Hebei Medical University, Shijiazhuang 050031, Hebei, PR China
| | - Xiao-Hui Xian
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang 050017, Hebei, PR China
| | - Qiao-Yun Song
- Department of Reproductive Genetics, Hebei General Hospital, Shijiazhuang 050051, Hebei, PR China
| | - Chao Pang
- Department of Pathology, The First Hospital of Hebei Medical University, Shijiazhuang 050031, Hebei, PR China
| | - Jia-Lei Wang
- Department of Laboratory Diagnosis, Hebei Medical University, Shijiazhuang 050017, Hebei, PR China
| | - Ming-Wei Wang
- Department of Neurology, The First Hospital of Hebei Medical University, Shijiazhuang 050031, Hebei, PR China; Brain Aging and Cognitive Neuroscience Laboratory of Hebei province, Shijiazhuang 050031, Hebei, PR China.
| | - Wen-Bin Li
- Department of Pathophysiology, Hebei Medical University, Shijiazhuang 050017, Hebei, PR China; Brain Aging and Cognitive Neuroscience Laboratory of Hebei province, Shijiazhuang 050031, Hebei, PR China.
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29
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Amyloid β Peptide-Induced Changes in Prefrontal Cortex Activity and Its Response to Hippocampal Input. INTERNATIONAL JOURNAL OF PEPTIDES 2017; 2017:7386809. [PMID: 28127312 PMCID: PMC5239987 DOI: 10.1155/2017/7386809] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/18/2016] [Accepted: 11/02/2016] [Indexed: 12/24/2022]
Abstract
Alterations in prefrontal cortex (PFC) function and abnormalities in its interactions with other brain areas (i.e., the hippocampus) have been related to Alzheimer Disease (AD). Considering that these malfunctions correlate with the increase in the brain's amyloid beta (Aβ) peptide production, here we looked for a causal relationship between these pathognomonic signs of AD. Thus, we tested whether or not Aβ affects the activity of the PFC network and the activation of this cortex by hippocampal input stimulation in vitro. We found that Aβ application to brain slices inhibits PFC spontaneous network activity as well as PFC activation, both at the population and at the single-cell level, when the hippocampal input is stimulated. Our data suggest that Aβ can contribute to AD by disrupting PFC activity and its long-range interactions throughout the brain.
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30
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Palop JJ, Mucke L. Network abnormalities and interneuron dysfunction in Alzheimer disease. Nat Rev Neurosci 2016; 17:777-792. [PMID: 27829687 DOI: 10.1038/nrn.2016.141] [Citation(s) in RCA: 608] [Impact Index Per Article: 76.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The function of neural circuits and networks can be controlled, in part, by modulating the synchrony of their components' activities. Network hypersynchrony and altered oscillatory rhythmic activity may contribute to cognitive abnormalities in Alzheimer disease (AD). In this condition, network activities that support cognition are altered decades before clinical disease onset, and these alterations predict future pathology and brain atrophy. Although the precise causes and pathophysiological consequences of these network alterations remain to be defined, interneuron dysfunction and network abnormalities have emerged as potential mechanisms of cognitive dysfunction in AD and related disorders. Here, we explore the concept that modulating these mechanisms may help to improve brain function in these conditions.
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Affiliation(s)
- Jorge J Palop
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, California 94158, USA.,Department of Neurology, University of California, San Francisco, 1650 Owens Street, San Francisco, California 94158, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, 1650 Owens Street, San Francisco, California 94158, USA.,Department of Neurology, University of California, San Francisco, 1650 Owens Street, San Francisco, California 94158, USA
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Klein AS, Donoso JR, Kempter R, Schmitz D, Beed P. Early Cortical Changes in Gamma Oscillations in Alzheimer's Disease. Front Syst Neurosci 2016; 10:83. [PMID: 27833535 PMCID: PMC5080538 DOI: 10.3389/fnsys.2016.00083] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2015] [Accepted: 10/14/2016] [Indexed: 12/19/2022] Open
Abstract
The entorhinal cortices in the temporal lobe of the brain are key structures relaying memory related information between the neocortex and the hippocampus. The medial entorhinal cortex (MEC) routes spatial information, whereas the lateral entorhinal cortex (LEC) routes predominantly olfactory information to the hippocampus. Gamma oscillations are known to coordinate information transfer between brain regions by precisely timing population activity of neuronal ensembles. Here, we studied the organization of in vitro gamma oscillations in the MEC and LEC of the transgenic (tg) amyloid precursor protein (APP)-presenilin 1 (PS1) mouse model of Alzheimer’s Disease (AD) at 4–5 months of age. In vitro gamma oscillations using the kainate model peaked between 30–50 Hz and therefore we analyzed the oscillatory properties in the 20–60 Hz range. Our results indicate that the LEC shows clear alterations in frequency and power of gamma oscillations at an early stage of AD as compared to the MEC. The gamma-frequency oscillation slows down in the LEC and also the gamma power in dorsal LEC is decreased as early as 4–5 months in the tg APP-PS1 mice. The results of this study suggest that the timing of olfactory inputs from LEC to the hippocampus might be affected at an early stage of AD, resulting in a possible erroneous integration of the information carried by the two input pathways to the hippocampal subfields.
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Affiliation(s)
| | - José R Donoso
- Department of Biology, Institute for Theoretical Biology, Humboldt UniversityBerlin, Germany; Bernstein Center for Computational NeuroscienceBerlin, Germany
| | - Richard Kempter
- Department of Biology, Institute for Theoretical Biology, Humboldt UniversityBerlin, Germany; Bernstein Center for Computational NeuroscienceBerlin, Germany
| | - Dietmar Schmitz
- Neuroscience Research Center, Charité UniversityBerlin, Germany; Bernstein Center for Computational NeuroscienceBerlin, Germany; Cluster of Excellence "NeuroCure", Charité UniversityBerlin, Germany; DZNE - German Center for Neurodegenerative DiseasesBerlin, Germany; Einstein Foundation BerlinBerlin, Germany
| | - Prateep Beed
- Neuroscience Research Center, Charité UniversityBerlin, Germany; DZNE - German Center for Neurodegenerative DiseasesBerlin, Germany; Berlin Institute of HealthBerlin, Germany
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Villanueva-Castillo C, Tecuatl C, Herrera-López G, Galván EJ. Aging-related impairments of hippocampal mossy fibers synapses on CA3 pyramidal cells. Neurobiol Aging 2016; 49:119-137. [PMID: 27794263 DOI: 10.1016/j.neurobiolaging.2016.09.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 09/15/2016] [Accepted: 09/17/2016] [Indexed: 11/16/2022]
Abstract
The network interaction between the dentate gyrus and area CA3 of the hippocampus is responsible for pattern separation, a process that underlies the formation of new memories, and which is naturally diminished in the aged brain. At the cellular level, aging is accompanied by a progression of biochemical modifications that ultimately affects its ability to generate and consolidate long-term potentiation. Although the synapse between dentate gyrus via the mossy fibers (MFs) onto CA3 neurons has been subject of extensive studies, the question of how aging affects the MF-CA3 synapse is still unsolved. Extracellular and whole-cell recordings from acute hippocampal slices of aged Wistar rats (34 ± 2 months old) show that aging is accompanied by a reduction in the interneuron-mediated inhibitory mechanisms of area CA3. Several MF-mediated forms of short-term plasticity, MF long-term potentiation and at least one of the critical signaling cascades necessary for potentiation are also compromised in the aged brain. An analysis of the spontaneous glutamatergic and gamma-aminobutyric acid-mediated currents on CA3 cells reveal a dramatic alteration in amplitude and frequency of the nonevoked events. CA3 cells also exhibited increased intrinsic excitability. Together, these results demonstrate that aging is accompanied by a decrease in the GABAergic inhibition, reduced expression of short- and long-term forms of synaptic plasticity, and increased intrinsic excitability.
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Affiliation(s)
| | - Carolina Tecuatl
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, México
| | | | - Emilio J Galván
- Departamento de Farmacobiología, Cinvestav Sede Sur, México City, México.
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33
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Huang L, Yang XJ, Huang Y, Sun EY, Sun M. Ketamine Protects Gamma Oscillations by Inhibiting Hippocampal LTD. PLoS One 2016; 11:e0159192. [PMID: 27467732 PMCID: PMC4965035 DOI: 10.1371/journal.pone.0159192] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Accepted: 06/28/2016] [Indexed: 12/02/2022] Open
Abstract
NMDA receptors have been widely reported to be involved in the regulation of synaptic plasticity through effects on long-term potentiation (LTP) and long-term depression (LTD). LTP and LTD have been implicated in learning and memory processes. Besides synaptic plasticity, it is known that the phenomenon of gamma oscillations is critical in cognitive functions. Synaptic plasticity has been widely studied, however it is still not clear, to what degree synaptic plasticity regulates the oscillations of neuronal networks. Two NMDA receptor antagonists, ketamine and memantine, have been shown to regulate LTP and LTD, to promote cognitive functions, and have even been reported to bring therapeutic effects in major depression and Alzheimer’s disease respectively. These compounds allow us to investigate the putative interrelationship between network oscillations and synaptic plasticity and to learn more about the mechanisms of their therapeutic effects. In the present study, we have identified that ketamine and memantine could inhibit LTD, without impairing LTP in the CA1 region of mouse hippocampus, which may underlie the mechanism of these drugs’ therapeutic effects. Our results suggest that NMDA-induced LTD caused a marked loss in the gamma power, and pretreatment with 10 μM ketamine prevented the oscillatory loss via its inhibitory effect on LTD. Our study provides a new understanding of the role of NMDA receptors on hippocampal plasticity and oscillations.
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Affiliation(s)
- Lanting Huang
- Neurodegeneration Discovery Performance Unit, GSK, R&D Shanghai, Building 1, 917 Halei Road, Zhangjiang Hi-tech Park, Pudong, Shanghai, China
- Stem Cell Translational Research Center, Tongji Hospital, School of Medicine, Collaborative Innovation Center for Brain Science, Tongji University, Shanghai, China
| | - Xiu-Juan Yang
- Neurodegeneration Discovery Performance Unit, GSK, R&D Shanghai, Building 1, 917 Halei Road, Zhangjiang Hi-tech Park, Pudong, Shanghai, China
| | - Ying Huang
- Department of Physiology and Pathophysiology, Shanghai Medical College, Fudan University, Shanghai, China
| | - Eve Y. Sun
- Stem Cell Translational Research Center, Tongji Hospital, School of Medicine, Collaborative Innovation Center for Brain Science, Tongji University, Shanghai, China
| | - Mu Sun
- Neurodegeneration Discovery Performance Unit, GSK, R&D Shanghai, Building 1, 917 Halei Road, Zhangjiang Hi-tech Park, Pudong, Shanghai, China
- * E-mail:
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Electrical and Network Neuronal Properties Are Preferentially Disrupted in Dorsal, But Not Ventral, Medial Entorhinal Cortex in a Mouse Model of Tauopathy. J Neurosci 2016; 36:312-24. [PMID: 26758825 DOI: 10.1523/jneurosci.2845-14.2016] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED The entorhinal cortex (EC) is one of the first areas to be disrupted in neurodegenerative diseases such as Alzheimer's disease and frontotemporal dementia. The responsiveness of individual neurons to electrical and environmental stimuli varies along the dorsal-ventral axis of the medial EC (mEC) in a manner that suggests this topographical organization plays a key role in neural encoding of geometric space. We examined the cellular properties of layer II mEC stellate neurons (mEC-SCs) in rTg4510 mice, a rodent model of neurodegeneration. Dorsoventral gradients in certain intrinsic membrane properties, such as membrane capacitance and afterhyperpolarizations, were flattened in rTg4510 mEC-SCs, while other cellular gradients [e.g., input resistance (Ri), action potential properties] remained intact. Specifically, the intrinsic properties of rTg4510 mEC-SCs in dorsal aspects of the mEC were preferentially affected, such that action potential firing patterns in dorsal mEC-SCs were altered, while those in ventral mEC-SCs were unaffected. We also found that neuronal oscillations in the gamma frequency band (30-80 Hz) were preferentially disrupted in the dorsal mEC of rTg4510 slices, while those in ventral regions were comparatively preserved. These alterations corresponded to a flattened dorsoventral gradient in theta-gamma cross-frequency coupling of local field potentials recorded from the mEC of freely moving rTg4510 mice. These differences were not paralleled by changes to the dorsoventral gradient in parvalbumin staining or neurodegeneration. We propose that the selective disruption to dorsal mECs, and the resultant flattening of certain dorsoventral gradients, may contribute to disturbances in spatial information processing observed in this model of dementia. SIGNIFICANCE STATEMENT The medial entorhinal cortex (mEC) plays a key role in spatial memory and is one of the first areas to express the pathological features of dementia. Neurons of the mEC are anatomically arranged to express functional dorsoventral gradients in a variety of neuronal properties, including grid cell firing field spacing, which is thought to encode geometric scale. We have investigated the effects of tau pathology on functional dorsoventral gradients in the mEC. Using electrophysiological approaches, we have shown that, in a transgenic mouse model of dementia, the functional properties of the dorsal mEC are preferentially disrupted, resulting in a flattening of some dorsoventral gradients. Our data suggest that neural signals arising in the mEC will have a reduced spatial content in dementia.
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Soluble amyloid beta oligomers block the learning-induced increase in hippocampal sharp wave-ripple rate and impair spatial memory formation. Sci Rep 2016; 6:22728. [PMID: 26947247 PMCID: PMC4779992 DOI: 10.1038/srep22728] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Accepted: 02/18/2016] [Indexed: 01/19/2023] Open
Abstract
Post-learning hippocampal sharp wave-ripples (SWRs) generated during slow wave sleep are thought to play a crucial role in memory formation. While in Alzheimer’s disease, abnormal hippocampal oscillations have been reported, the functional contribution of SWRs to the typically observed spatial memory impairments remains unclear. These impairments have been related to degenerative synaptic changes produced by soluble amyloid beta oligomers (Aβos) which, surprisingly, seem to spare the SWR dynamics during routine behavior. To unravel a potential effect of Aβos on SWRs in cognitively-challenged animals, we submitted vehicle- and Aβo-injected mice to spatial recognition memory testing. While capable of forming short-term recognition memory, Aβ mice exhibited faster forgetting, suggesting successful encoding but an inability to adequately stabilize and/or retrieve previously acquired information. Without prior cognitive requirements, similar properties of SWRs were observed in both groups. In contrast, when cognitively challenged, the post-encoding and -recognition peaks in SWR occurrence observed in controls were abolished in Aβ mice, indicating impaired hippocampal processing of spatial information. These results point to a crucial involvement of SWRs in spatial memory formation and identify the Aβ-induced impairment in SWRs dynamics as a disruptive mechanism responsible for the spatial memory deficits associated with Alzheimer’s disease.
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Jessen SB, Mathiesen C, Lind BL, Lauritzen M. Interneuron Deficit Associates Attenuated Network Synchronization to Mismatch of Energy Supply and Demand in Aging Mouse Brains. Cereb Cortex 2015; 27:646-659. [DOI: 10.1093/cercor/bhv261] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- Sanne Barsballe Jessen
- Department of Neuroscience and Pharmacology
- Center for Healthy Aging, University of Copenhagen, Copenhagen N 2200, Denmark
| | - Claus Mathiesen
- Department of Neuroscience and Pharmacology
- Center for Healthy Aging, University of Copenhagen, Copenhagen N 2200, Denmark
| | | | - Martin Lauritzen
- Department of Neuroscience and Pharmacology
- Center for Healthy Aging, University of Copenhagen, Copenhagen N 2200, Denmark
- Department of Clinical Neurophysiology, Glostrup Hospital, Glostrup 2600, Denmark
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Lei M, Xu H, Li Z, Wang Z, O'Malley TT, Zhang D, Walsh DM, Xu P, Selkoe DJ, Li S. Soluble Aβ oligomers impair hippocampal LTP by disrupting glutamatergic/GABAergic balance. Neurobiol Dis 2015; 85:111-121. [PMID: 26525100 DOI: 10.1016/j.nbd.2015.10.019] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Revised: 09/01/2015] [Accepted: 10/21/2015] [Indexed: 02/06/2023] Open
Abstract
Epileptic activity may be more prevalent in early stage Alzheimer's disease (AD) than previously believed. Several studies report spontaneous seizures and interictal discharges in mouse models of AD undergoing age-related Aβ accumulation. The mechanism by which Aβ-induced neuronal excitability can trigger epileptiform activity remains unknown. Here, we systematically examined field excitatory postsynaptic potentials (fEPSP) in stratum radiatum and population spikes (PSs) in the adjacent stratum pyramidale of CA1 in wild-type mouse hippocampal slices. Soluble Aβ oligomers (oAβ) blocked hippocampal LTP and EPSP-spike (E-S) potentiation, and these effects were occluded by prior treatment with the glutamate uptake inhibitor TBOA. In accord, oAβ elevated glutamate levels in the hippocampal slice medium. Recording the PS revealed that oAβ increased PS frequency and reduced LTP, and this LTP deficit was occluded by pretreatment with the GABAA antagonist picrotoxin. Whole-cell recordings showed that oAβ significantly increased spontaneous EPSC frequency. Decreasing neuronal activity by increasing GABA tone or partially blocking NMDAR activity prevented oAβ impairment of hippocampal LTP. Finally, treating slices with two antiepileptic drugs rescued the LTP inhibition induced by oAβ. We conclude that soluble Aβ oligomers at the low nanomolar levels present in AD brain increase neuronal excitability by disrupting glutamatergic/GABAergic balance, thereby impairing synaptic plasticity.
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Affiliation(s)
- Ming Lei
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China
| | - Huixin Xu
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Zhangyuan Li
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Zemin Wang
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Tiernan T O'Malley
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Dainan Zhang
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Dominic M Walsh
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Pingyi Xu
- Department of Neurology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080, China; Department of Neurology, The First Affiliated Hospital of Guangzhou Medical University, Guangdong 510120, China.
| | - Dennis J Selkoe
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Shaomin Li
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
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Scutt G, Allen M, Kemenes G, Yeoman M. A switch in the mode of the sodium/calcium exchanger underlies an age-related increase in the slow afterhyperpolarization. Neurobiol Aging 2015; 36:2838-49. [PMID: 26163984 DOI: 10.1016/j.neurobiolaging.2015.06.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Revised: 06/08/2015] [Accepted: 06/08/2015] [Indexed: 12/19/2022]
Abstract
During aging, the Ca(2+)-sensitive slow afterhyperpolarization (sAHP) of hippocampal neurons is known to increase in duration. This change has also been observed in the serotonergic cerebral giant cells (CGCs) of the pond snail Lymnaea stagnalis, but has yet to be characterized. In this article, we confirm that there is a reduction in firing rate, an increase in the duration of the sAHP, and an alteration in the strength and speed of spike frequency adaptation in the CGCs during aging, a finding that is compatible with an increase in the sAHP current. We go on to show that age-related changes in the kinetics of spike frequency adaptation are consistent with a reduction in Ca(2+) clearance from the cell, which we confirm with Ca(2+) imaging and pharmacological manipulation of the sodium calcium exchanger. These experiments suggest that the sodium calcium exchanger may be switching to a reverse-mode configuration in the CGCs during aging.
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Affiliation(s)
- Greg Scutt
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK.
| | - Marcus Allen
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
| | - György Kemenes
- Sussex Neuroscience, School of Life Sciences, University of Sussex, Falmer, Brighton, UK
| | - Mark Yeoman
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Brighton, UK
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Wang F, Zhang Y, Wang L, Sun P, Luo X, Ishigaki Y, Sugai T, Yamamoto R, Kato N. Improvement of spatial learning by facilitating large-conductance calcium-activated potassium channel with transcranial magnetic stimulation in Alzheimer's disease model mice. Neuropharmacology 2015; 97:210-9. [PMID: 26051398 DOI: 10.1016/j.neuropharm.2015.05.027] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Revised: 05/04/2015] [Accepted: 05/26/2015] [Indexed: 01/13/2023]
Abstract
Transcranial magnetic stimulation (TMS) is fragmentarily reported to be beneficial to Alzheimer's patients. Its underlying mechanism was investigated. TMS was applied at 1, 10 or 15 Hz daily for 4 weeks to young Alzheimer's disease model mice (3xTg), in which intracellular soluble amyloid-β is notably accumulated. Hippocampal long-term potentiation (LTP) was tested after behavior. TMS ameliorated spatial learning deficits and enhanced LTP in the same frequency-dependent manner. Activity of the large conductance calcium-activated potassium (Big-K; BK) channels was suppressed in 3xTg mice and recovered by TMS frequency-dependently. These suppression and recovery were accompanied by increase and decrease in cortical excitability, respectively. TMS frequency-dependently enhanced the expression of the activity-dependently expressed scaffold protein Homer1a, which turned out to enhance BK channel activity. Isopimaric acid, an activator of the BK channel, magnified LTP. Amyloid-β lowering was detected after TMS in 3xTg mice. In 3xTg mice with Homer1a knocked out, amyloid-β lowering was not detected, though the TMS effects on BK channel and LTP remained. We concluded that TMS facilitates BK channels both Homer1a-dependently and -independently, thereby enhancing hippocampal LTP and decreasing cortical excitability. Reduced excitability contributed to amyloid-β lowering. A cascade of these correlated processes, triggered by TMS, was likely to improve learning in 3xTg mice.
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Affiliation(s)
- Furong Wang
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan; Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yu Zhang
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan; Medical College, Qinghai University, Xinin 810016, China
| | - Li Wang
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan; China-Japan Friendship Hospital, Beijing 100029, China
| | - Peng Sun
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan; Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Xianwen Luo
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan; Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
| | - Yasuhito Ishigaki
- Medical Research Institute, Kanazawa Medical University, Ishikawa 920-0293, Japan
| | - Tokio Sugai
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan
| | - Ryo Yamamoto
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan
| | - Nobuo Kato
- Department of Physiology, Kanazawa Medical University, Ishikawa 920-0293, Japan.
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Zhang X, Ge XY, Wang JG, Wang YL, Wang Y, Yu Y, Li PP, Lu CB. Induction of long-term oscillations in the γ frequency band by nAChR activation in rat hippocampal CA3 area. Neuroscience 2015; 301:49-60. [PMID: 26049144 DOI: 10.1016/j.neuroscience.2015.05.060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 05/19/2015] [Accepted: 05/22/2015] [Indexed: 01/08/2023]
Abstract
The hippocampal neuronal network oscillation at γ frequency band (γ oscillation) is generated by the precise interaction between interneurons and principle cells. γ oscillation is associated with attention, learning and memory and is impaired in the diseased conditions such as Alzheimer's disease (AD) and schizophrenia. Nicotinic acetylcholine receptor (nAChR) plays an important role in the regulation of hippocampal neurotransmission and network activity. It is not known whether nicotine modulates plasticity of network activity at γ oscillations in the hippocampus. In this study we investigated the effects of nicotine on the long-term changes of KA-induced γ oscillations. We found that hippocampal γ oscillations can be enhanced by a low concentration of nicotine (1μM), such an enhancement lasts for hours after washing out of nicotine, suggesting a form of synaptic plasticity, named as long-term oscillation at γ frequency band (LTOγ). Nicotine-induced LTOγ was mimicked by the selective α4β2 but not by α7 nAChR agonist and was involved in N-methyl-d-aspartate (NMDA) receptor activation as well as depended on excitatory and inhibitory neurotransmission. Our results indicate that nAChR activation induced plasticity in γ oscillation, which may be beneficial for the improvement of cognitive deficiency in AD and schizophrenia.
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Affiliation(s)
- X Zhang
- Key Laboratory of Brain Research of Henan Province, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang 453003, Henan, PR China
| | - X Y Ge
- Key Laboratory of Brain Research of Henan Province, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang 453003, Henan, PR China
| | - J G Wang
- Department of Pathophysiology, Xinxiang Medical University, Xinxiang 453003, Henan, PR China
| | - Y L Wang
- Key Laboratory of Brain Research of Henan Province, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang 453003, Henan, PR China
| | - Y Wang
- Key Laboratory of Brain Research of Henan Province, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang 453003, Henan, PR China
| | - Y Yu
- Department of Biomedical Engineering, Xinxiang Medical University, Xinxiang 453003, Henan, PR China
| | - P P Li
- Key Laboratory of Brain Research of Henan Province, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang 453003, Henan, PR China
| | - C B Lu
- Key Laboratory of Brain Research of Henan Province, Department of Physiology and Neurobiology, Xinxiang Medical University, Xinxiang 453003, Henan, PR China.
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41
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Neuronal Network Oscillations in Neurodegenerative Diseases. Neuromolecular Med 2015; 17:270-84. [PMID: 25920466 DOI: 10.1007/s12017-015-8355-9] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2015] [Accepted: 04/16/2015] [Indexed: 10/23/2022]
Abstract
Cognitive and behavioral acts go along with highly coordinated spatiotemporal activity patterns in neuronal networks. Most of these patterns are synchronized by coherent membrane potential oscillations within and between local networks. By entraining multiple neurons into a common time regime, such network oscillations form a critical interface between cellular activity and large-scale systemic functions. Synaptic integrity is altered in neurodegenerative diseases, and it is likely that this goes along with characteristic changes of coordinated network activity. This notion is supported by EEG recordings from human patients and from different animal models of such disorders. However, our knowledge about the pathophysiology of network oscillations in neurodegenerative diseases is surprisingly incomplete, and increased research efforts are urgently needed. One complicating factor is the pronounced diversity of network oscillations between different brain regions and functional states. Pathological changes must, therefore, be analyzed separately in each condition and affected area. However, cumulative evidence from different diseases may result, in the future, in more unifying "oscillopathy" concepts of neurodegenerative diseases. In this review, we report present evidence for pathological changes of network oscillations in Alzheimer's disease (AD), one of the most prominent and challenging neurodegenerative disorders. The heterogeneous findings from AD are contrasted to Parkinson's disease, where motor-related changes in specific frequency bands do already fulfill criteria of a valid biomarker.
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42
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Wang Y, Wang Z, Wang J, Wang Y, Henderson Z, Wang X, Zhang X, Song J, Lu C. The modulation of nicotinic acetylcholine receptors on the neuronal network oscillations in rat hippocampal CA3 area. Sci Rep 2015; 5:9493. [PMID: 25810076 PMCID: PMC4374140 DOI: 10.1038/srep09493] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 03/05/2015] [Indexed: 11/28/2022] Open
Abstract
γ oscillations are associated with higher brain functions such as memory, perception and consciousness. Disruption of γ oscillations occur in various neuro-psychological disorders such as schizophrenia. Nicotinic acetylcholine receptors (nAChR) are highly expressed in the hippocampus, however, little is known about the role on hippocampal persistent γ oscillation. This study examined the effects of nicotine and selective nAChR agonists and antagonists on kainate-induced persistent γ oscillation in rat hippocampal slices. Nicotine enhanced γ oscillation at concentrations of 0.1–10 μM, but reduced it at a higher concentration of 100 μM. The enhancement on γ oscillation can be best mimicked by co-application of α4β2- and α7- nAChR agonist and reduced by a combination of nAChR antagonists, DhβE and MLA. However, these nAChR antagonists failed to block the suppressing role of nicotine on γ. Furthermore, we found that the NMDA receptor antagonist D-AP5 completely blocked the effect of nicotine. These results demonstrate that nicotine modulates γ oscillations via α7 and α4β2 nAChR as well as NMDA activation, suggesting that nAChR activation may have a therapeutic role for the clinical disorder such as schizophrenia, which is known to have impaired γ oscillation and hypo-NMDA receptor function.
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Affiliation(s)
- Yang Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, Henan Province, Henan PR. China
| | - Zhan Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, Henan Province, Henan PR. China
| | - Jiangang Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, Henan Province, Henan PR. China
| | - Yali Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, Henan Province, Henan PR. China
| | - Zaineb Henderson
- Institute of Membrane and System Biology, University of Leeds, Leeds, England
| | - Xiaofang Wang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, Henan Province, Henan PR. China
| | - Xi Zhang
- Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, Henan Province, Henan PR. China
| | - Jinggui Song
- Psychiatric Hospital of Henan Province, 2nd Affiliated Hospital of Xinxiang Medical University
| | - Chengbiao Lu
- 1] Key Laboratory for the Brain Research of Henan Province, Xinxiang Medical University, Henan Province, Henan PR. China [2] Psychiatric Hospital of Henan Province, 2nd Affiliated Hospital of Xinxiang Medical University
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Functional relationships between the hippocampus and dorsomedial striatum in learning a visual scene-based memory task in rats. J Neurosci 2015; 34:15534-47. [PMID: 25411483 DOI: 10.1523/jneurosci.0622-14.2014] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
The hippocampus is important for contextual behavior, and the striatum plays key roles in decision making. When studying the functional relationships with the hippocampus, prior studies have focused mostly on the dorsolateral striatum (DLS), emphasizing the antagonistic relationships between the hippocampus and DLS in spatial versus response learning. By contrast, the functional relationships between the dorsomedial striatum (DMS) and hippocampus are relatively unknown. The current study reports that lesions to both the hippocampus and DMS profoundly impaired performance of rats in a visual scene-based memory task in which the animals were required to make a choice response by using visual scenes displayed in the background. Analysis of simultaneous recordings of local field potentials revealed that the gamma oscillatory power was higher in the DMS, but not in CA1, when the rat performed the task using familiar scenes than novel ones. In addition, the CA1-DMS networks increased coherence at γ, but not at θ, rhythm as the rat mastered the task. At the single-unit level, the neuronal populations in CA1 and DMS showed differential firing patterns when responses were made using familiar visual scenes than novel ones. Such learning-dependent firing patterns were observed earlier in the DMS than in CA1 before the rat made choice responses. The present findings suggest that both the hippocampus and DMS process memory representations for visual scenes in parallel with different time courses and that flexible choice action using background visual scenes requires coordinated operations of the hippocampus and DMS at γ frequencies.
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Kerrigan TL, Brown JT, Randall AD. Characterization of altered intrinsic excitability in hippocampal CA1 pyramidal cells of the Aβ-overproducing PDAPP mouse. Neuropharmacology 2014; 79:515-24. [PMID: 24055500 PMCID: PMC3989024 DOI: 10.1016/j.neuropharm.2013.09.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Revised: 08/21/2013] [Accepted: 09/04/2013] [Indexed: 11/27/2022]
Abstract
Transgenic mice that accumulate Aβ peptides in the CNS are commonly used to interrogate functional consequences of Alzheimer's disease-associated amyloidopathy. In addition to changes to synaptic function, there is also growing evidence that changes to intrinsic excitability of neurones can arise in these models of amyloidopathy. Furthermore, some of these alterations to intrinsic properties may occur relatively early within the age-related progression of experimental amyloidopathy. Here we report a detailed comparison between the intrinsic excitability properties of hippocampal CA1 pyramidal neurones in wild-type (WT) and PDAPP mice. The latter is a well-established model of Aβ accumulation which expresses human APP harbouring the Indiana (V717F) mutation. At the age employed in this study (9-10 months) CNS Abeta was elevated in PDAPP mice but significant plaque pathology was absent. PDAPP mice exhibited no differences in subthreshold intrinsic properties including resting potential, input resistance, membrane time constant and sag. When CA1 cells of PDAPP mice were given depolarizing stimuli of various amplitudes they initially fired at a higher frequency than WT cells. Commensurate with this, PDAPP cells exhibited a larger fast afterdepolarizing potential. PDAPP mice had narrower spikes but action potential threshold, rate of rise and peak were not different. Thus not all changes seen in our previous studies of amyloidopathy models were present in PDAPP mice; however, narrower spikes, larger ADPs and the propensity to fire at higher frequencies were consistent with our prior work and thus may represent robust, cross-model, indices of amyloidopathy. This article is part of a Special Issue entitled 'Neurodevelopment Disorder'.
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Affiliation(s)
- T L Kerrigan
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK
| | - J T Brown
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, The Hatherly Building, Exeter EX4 4PS, UK
| | - A D Randall
- School of Physiology and Pharmacology, University of Bristol, University Walk, Bristol BS8 1TD, UK; Institute of Biomedical and Clinical Sciences, University of Exeter Medical School, The Hatherly Building, Exeter EX4 4PS, UK.
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Amyloid Beta peptides differentially affect hippocampal theta rhythms in vitro. INTERNATIONAL JOURNAL OF PEPTIDES 2013; 2013:328140. [PMID: 23878547 PMCID: PMC3708430 DOI: 10.1155/2013/328140] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/24/2013] [Accepted: 06/03/2013] [Indexed: 12/27/2022]
Abstract
Soluble amyloid beta peptide (A β ) is responsible for the early cognitive dysfunction observed in Alzheimer's disease. Both cholinergically and glutamatergically induced hippocampal theta rhythms are related to learning and memory, spatial navigation, and spatial memory. However, these two types of theta rhythms are not identical; they are associated with different behaviors and can be differentially modulated by diverse experimental conditions. Therefore, in this study, we aimed to investigate whether or not application of soluble A β alters the two types of theta frequency oscillatory network activity generated in rat hippocampal slices by application of the cholinergic and glutamatergic agonists carbachol or DHPG, respectively. Due to previous evidence that oscillatory activity can be differentially affected by different A β peptides, we also compared Aβ 25-35 and Aβ 1-42 for their effects on theta rhythms in vitro at similar concentrations (0.5 to 1.0 μ M). We found that Aβ 25-35 reduces, with less potency than Aβ 1-42, carbachol-induced population theta oscillatory activity. In contrast, DHPG-induced oscillatory activity was not affected by a high concentration of Aβ 25-35 but was reduced by Aβ 1-42. Our results support the idea that different amyloid peptides might alter specific cellular mechanisms related to the generation of specific neuronal network activities, instead of exerting a generalized inhibitory effect on neuronal network function.
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Oliva CA, Vargas JY, Inestrosa NC. Wnt signaling: role in LTP, neural networks and memory. Ageing Res Rev 2013; 12:786-800. [PMID: 23665425 DOI: 10.1016/j.arr.2013.03.006] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2012] [Revised: 02/15/2013] [Accepted: 03/05/2013] [Indexed: 01/07/2023]
Abstract
Wnt components are key regulators of a variety of developmental processes, including embryonic patterning, cell specification, and cell polarity. The Wnt signaling pathway participates in the development of the central nervous system and growing evidence indicates that Wnts also regulates the function of the adult nervous system. In fact, most of the key components including Wnts and Frizzled receptors are expressed in the adult brain. Wnt ligands have been implicated in the regulation of synaptic assembly as well as in neurotransmission and synaptic plasticity. Deregulation of Wnt signaling has been associated with several pathologies, and more recently has been related to neurodegenerative diseases and to mental and mood disorders. In this review, we focus our attention on the Wnt signaling cascade in postnatal life and we review in detail the presence of Wnt signaling components in pre- and postsynaptic regions. Due to the important role of Wnt proteins in wiring neural circuits, we discuss recent findings about the role of Wnt pathways both in basal spontaneous activities as well as in activity-dependent processes that underlie synaptic plasticity. Finally, we review the role of Wnt in vivo and we finish with the most recent data in literature that involves the effect of components of the Wnt signaling pathway in neurological and mental disorders, including a special emphasis on in vivo studies that relate behavioral abnormalities to deficiencies in Wnt signaling, as well as the data that support a neuroprotective role of Wnt proteins in relation to the pathogenesis of Alzheimer's disease.
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Encoding of rat working memory by power of multi-channel local field potentials via sparse non-negative matrix factorization. Neurosci Bull 2013; 29:279-86. [PMID: 23606209 DOI: 10.1007/s12264-013-1333-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2012] [Accepted: 12/17/2012] [Indexed: 12/27/2022] Open
Abstract
Working memory plays an important role in human cognition. This study investigated how working memory was encoded by the power of multi-channel local field potentials (LFPs) based on sparse nonnegative matrix factorization (SNMF). SNMF was used to extract features from LFPs recorded from the prefrontal cortex of four Sprague-Dawley rats during a memory task in a Y maze, with 10 trials for each rat. Then the power-increased LFP components were selected as working memory-related features and the other components were removed. After that, the inverse operation of SNMF was used to study the encoding of working memory in the time-frequency domain. We demonstrated that theta and gamma power increased significantly during the working memory task. The results suggested that postsynaptic activity was simulated well by the sparse activity model. The theta and gamma bands were meaningful for encoding working memory.
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Hippocampal network oscillations in APP/APLP2-deficient mice. PLoS One 2013; 8:e61198. [PMID: 23585881 PMCID: PMC3621758 DOI: 10.1371/journal.pone.0061198] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Accepted: 03/08/2013] [Indexed: 11/19/2022] Open
Abstract
The physiological function of amyloid precursor protein (APP) and its two homologues APP-like protein 1 (APLP1) and 2 (APLP2) is largely unknown. Previous work suggests that lack of APP or APLP2 impairs synaptic plasticity and spatial learning. There is, however, almost no data on the role of APP or APLP at the network level which forms a critical interface between cellular functions and behavior. We have therefore investigated memory-related synaptic and network functions in hippocampal slices from three lines of transgenic mice: APPsα-KI (mice expressing extracellular fragment of APP, corresponding to the secreted APPsα ectodomain), APLP2-KO, and combined APPsα-KI/APLP2-KO (APPsα-DM for “double mutants”). We analyzed two prominent patterns of network activity, gamma oscillations and sharp-wave ripple complexes (SPW-R). Both patterns were generally preserved in all strains. We find, however, a significantly reduced frequency of gamma oscillations in CA3 of APLP2-KO mice in comparison to APPsα-KI and WT mice. Network activity, basic synaptic transmission and short-term plasticity were unaltered in the combined mutants (APPsα-DM) which showed, however, reduced long-term potentiation (LTP). Together, our data indicate that APLP2 and the intracellular domain of APP are not essential for coherent activity patterns in the hippocampus, but have subtle effects on synaptic plasticity and fine-tuning of network oscillations.
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Kanak DJ, Rose GM, Zaveri HP, Patrylo PR. Altered network timing in the CA3-CA1 circuit of hippocampal slices from aged mice. PLoS One 2013; 8:e61364. [PMID: 23593474 PMCID: PMC3620228 DOI: 10.1371/journal.pone.0061364] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2012] [Accepted: 03/07/2013] [Indexed: 01/05/2023] Open
Abstract
Network patterns are believed to provide unique temporal contexts for coordinating neuronal activity within and across different regions of the brain. Some of the characteristics of network patterns modeled in vitro are altered in the CA3 or CA1 subregions of hippocampal slices from aged mice. CA3-CA1 network interactions have not been examined previously. We used slices from aged and adult mice to model spontaneous sharp wave ripples and carbachol-induced gamma oscillations, and compared measures of CA3-CA1 network timing between age groups. Coherent sharp wave ripples and gamma oscillations were evident in the CA3-CA1 circuit in both age groups, but the relative timing of activity in CA1 stratum pyramidale was delayed in the aged. In another sample of aged slices, evoked Schaffer collateral responses were attenuated in CA3 (antidromic spike amplitude) and CA1 (orthodromic field EPSP slope). However, the amplitude and timing of spontaneous sharp waves recorded in CA1 stratum radiatum were similar to adults. In both age groups unit activity recorded juxtacellularly from unidentified neurons in CA1 stratum pyramidale and stratum oriens was temporally modulated by CA3 ripples. However, aged neurons exhibited reduced spike probability during the early cycles of the CA3 ripple oscillation. These findings suggest that aging disrupts the coordination of patterned activity in the CA3-CA1 circuit.
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Affiliation(s)
- Daniel J Kanak
- Department of Physiology, Southern Illinois University School of Medicine, Carbondale, Illinois, United States of America.
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Hippocampal excitability is increased in aged mice. Exp Neurol 2013; 247:710-9. [PMID: 23510762 DOI: 10.1016/j.expneurol.2013.03.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2012] [Revised: 03/05/2013] [Accepted: 03/08/2013] [Indexed: 12/22/2022]
Abstract
Aging is known to be associated with a high risk of developing seizure disorders. Currently, the mechanisms underlying this increased seizure susceptibility are not fully understood. Several previous studies have shown a loss of subgroups of GABAergic inhibitory interneurons in the hippocampus of aged rodents, yet the network excitability intrinsic to the aged hippocampus remains to be elucidated. The aim of this study is to examine age-dependent changes of hippocampal network activities in young adult (3-5 months), aging (16-18 months), and aged (24-28 months) mice. We conducted intracranial electroencephalographic (EEG) recordings in free-moving animals and extracellular recordings in hippocampal slices in vitro. EEG recordings revealed frequent spikes in aging and aged mice but only occasionally in young adults. These EEG spikes were suppressed following diazepam administration. Spontaneous field potentials with large amplitudes were frequently observed in hippocampal slices of aged mice but rarely in slices from young adults. These spontaneous field potentials originated from the CA3 area and their generation was dependent upon the excitatory glutamatergic activity. We therefore postulate that hippocampal network excitability is increased in aged mice and that such hyperactivity may be relevant to the increased seizure susceptibility observed in aged subjects.
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