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Navakkode S, Kennedy BK. Neural ageing and synaptic plasticity: prioritizing brain health in healthy longevity. Front Aging Neurosci 2024; 16:1428244. [PMID: 39161341 PMCID: PMC11330810 DOI: 10.3389/fnagi.2024.1428244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2024] [Accepted: 07/24/2024] [Indexed: 08/21/2024] Open
Abstract
Ageing is characterized by a gradual decline in the efficiency of physiological functions and increased vulnerability to diseases. Ageing affects the entire body, including physical, mental, and social well-being, but its impact on the brain and cognition can have a particularly significant effect on an individual's overall quality of life. Therefore, enhancing lifespan and physical health in longevity studies will be incomplete if cognitive ageing is over looked. Promoting successful cognitive ageing encompasses the objectives of mitigating cognitive decline, as well as simultaneously enhancing brain function and cognitive reserve. Studies in both humans and animal models indicate that cognitive decline related to normal ageing and age-associated brain disorders are more likely linked to changes in synaptic connections that form the basis of learning and memory. This activity-dependent synaptic plasticity reorganises the structure and function of neurons not only to adapt to new environments, but also to remain robust and stable over time. Therefore, understanding the neural mechanisms that are responsible for age-related cognitive decline becomes increasingly important. In this review, we explore the multifaceted aspects of healthy brain ageing with emphasis on synaptic plasticity, its adaptive mechanisms and the various factors affecting the decline in cognitive functions during ageing. We will also explore the dynamic brain and neuroplasticity, and the role of lifestyle in shaping neuronal plasticity.
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Affiliation(s)
- Sheeja Navakkode
- Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, Centre for Healthy Longevity, National University Health System, National University of Singapore, Singapore, Singapore
- Life Sciences Institute Neurobiology Programme, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
| | - Brian K. Kennedy
- Healthy Longevity Translational Research Program, Yong Loo Lin School of Medicine, Centre for Healthy Longevity, National University Health System, National University of Singapore, Singapore, Singapore
- Life Sciences Institute Neurobiology Programme, Centre for Life Sciences, National University of Singapore, Singapore, Singapore
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Departments of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore
- Buck Institute for Research on Ageing, Novato, CA, United States
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Bin Ibrahim MZ, Wang Z, Sajikumar S. Synapses tagged, memories kept: synaptic tagging and capture hypothesis in brain health and disease. Philos Trans R Soc Lond B Biol Sci 2024; 379:20230237. [PMID: 38853570 PMCID: PMC11343274 DOI: 10.1098/rstb.2023.0237] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2023] [Revised: 01/29/2024] [Accepted: 02/13/2024] [Indexed: 06/11/2024] Open
Abstract
The synaptic tagging and capture (STC) hypothesis lays the framework on the synapse-specific mechanism of protein synthesis-dependent long-term plasticity upon synaptic induction. Activated synapses will display a transient tag that will capture plasticity-related products (PRPs). These two events, tag setting and PRP synthesis, can be teased apart and have been studied extensively-from their electrophysiological and pharmacological properties to the molecular events involved. Consequently, the hypothesis also permits interactions of synaptic populations that encode different memories within the same neuronal population-hence, it gives rise to the associativity of plasticity. In this review, the recent advances and progress since the experimental debut of the STC hypothesis will be shared. This includes the role of neuromodulation in PRP synthesis and tag integrity, behavioural correlates of the hypothesis and modelling in silico. STC, as a more sensitive assay for synaptic health, can also assess neuronal aberrations. We will also expound how synaptic plasticity and associativity are altered in ageing-related decline and pathological conditions such as juvenile stress, cancer, sleep deprivation and Alzheimer's disease. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.
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Affiliation(s)
- Mohammad Zaki Bin Ibrahim
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore119077, Singapore
| | - Zijun Wang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore119077, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore119077, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore117597, Singapore
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Manakkadan A, Krishnan D, Rui Xia Ang S, Sajikumar S. Slow Release of Hydrogen Sulfide in CA1 Hippocampal Neurons Rescues Long-Term Synaptic Plasticity and Associativity in an Amyloid-β Induced Model of Alzheimer's Disease. J Alzheimers Dis 2024; 101:913-921. [PMID: 39302367 DOI: 10.3233/jad-240456] [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] [Indexed: 09/22/2024]
Abstract
Background Impairment of synaptic plasticity along with the formation of amyloid-β (Aβ) plaques and tau-protein neurofibrillary tangles have been associated with Alzheimer's disease (AD). Earlier studies with rat and mouse hippocampal slices have revealed the association of AD with the absence of synthesis of memory related proteins leading to impairment in cognitive functions. The role of hydrogen sulfide (H2S), a gaseous neurotransmitter, has been gaining attention as a neuroprotective agent. However, its role in AD-like conditions has not been studied so far. Objective To study the neuroprotective role of H2S in AD conditions using rat hippocampal slices and the organic molecule GYY4137, a slow releasing H2S donor. Methods Electrophysiological recordings were carried out in rat hippocampal slices to look into the impairment of LTP, a cellular correlate of memory. The Aβ42 peptide was bath-applied to mimic AD-like conditions and checked for both late-LTP and synaptic tagging and capture (STC) mechanisms of the synapses. GYY4137 was applied to look into its neuroprotective role at different stages during the recording of fEPSP. Results There has been a steady decline in the plasticity properties of the synapses, in the form of late-LTP and STC, after the application of Aβ42 peptide in the hippocampal slices. However, application of GYY4137 rescued these conditions in vitro. Conclusions GYY4137, with its slow release of H2S, could possibly act as a therapeutic agent in cognitive dysfunctions of the brain, mainly AD.
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Affiliation(s)
- Anoop Manakkadan
- Department of Physiology, National University of Singapore, Singapore
- Neurobiology/Aging Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore
| | - Dolly Krishnan
- Department of Physiology, National University of Singapore, Singapore
| | - Sheila Rui Xia Ang
- Department of Physiology, National University of Singapore, Singapore
- Neurobiology/Aging Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, National University of Singapore, Singapore
- Neurobiology/Aging Programme, Life Sciences Institute, Centre for Life Sciences, National University of Singapore, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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Torres R, Hidalgo C. Subcellular localization and transcriptional regulation of brain ryanodine receptors. Functional implications. Cell Calcium 2023; 116:102821. [PMID: 37949035 DOI: 10.1016/j.ceca.2023.102821] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 10/16/2023] [Accepted: 11/03/2023] [Indexed: 11/12/2023]
Abstract
Ryanodine receptors (RyR) are intracellular Ca2+ channels localized in the endoplasmic reticulum, where they act as critical mediators of Ca2+-induced Ca2+ calcium release (CICR). In the brain, mammals express in both neurons, and non-neuronal cells, a combination of the three RyR-isoforms (RyR1-3). Pharmacological approaches, which do not distinguish between isoforms, have indicated that RyR-isoforms contribute to brain function. However, isoform-specific manipulations have revealed that RyR-isoforms display different subcellular localizations and are differentially associated with neuronal function. These findings raise the need to understand RyR-isoform specific transcriptional regulation, as this knowledge will help to elucidate the causes of neuronal dysfunction for a growing list of brain disorders that show altered RyR channel expression and function.
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Affiliation(s)
- Rodrigo Torres
- Facultad de Medicina y Ciencia, Universidad San Sebastián, Lago Panguipulli 1390, 5501842, Puerto Montt, Chile.
| | - Cecilia Hidalgo
- Department of Neurosciences. Biomedical Neuroscience Institute, Physiology and Biophysics Program, Institute of Biomedical Sciences, Center for Exercise, Metabolism and Cancer Studies, Faculty of Medicine, Universidad de Chile, Santiago, 8380000, Chile
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Zhu Y, Mei Y, Baby N, Teo HY, Binte Hanafi Z, Mohd Salleh SN, Sajikumar S, Liu H. Tumor-mediated microbiota alteration impairs synaptic tagging/capture in the hippocampal CA1 area via IL-1β production. Commun Biol 2023; 6:685. [PMID: 37400621 DOI: 10.1038/s42003-023-05036-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2022] [Accepted: 06/12/2023] [Indexed: 07/05/2023] Open
Abstract
Cancer patients often experience impairments in cognitive function. However, the evidence for tumor-mediated neurological impairment and detailed mechanisms are still lacking. Gut microbiota has been demonstrated to be involved in the immune system homeostasis and brain functions. Here we find that hepatocellular carcinoma (HCC) growth alters the gut microbiota and impedes the cognitive functions. The synaptic tagging and capture (STC), an associative cellular mechanism for the formation of associative memory, is impaired in the tumor-bearing mice. STC expression is rescued after microbiota sterilization. Transplantation of microbiota from HCC tumor-bearing mice induces similar STC impairment in wide type mice. Mechanistic study reveals that HCC growth significantly elevates the serum and hippocampus IL-1β levels. IL-1β depletion in the HCC tumor-bearing mice restores the STC. Taken together, these results demonstrate that gut microbiota plays a crucial role in mediating the tumor-induced impairment of the cognitive function via upregulating IL-1β production.
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Affiliation(s)
- Ying Zhu
- Immunology Translational Research Programme, Department of Microbiology of Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Yu Mei
- Immunology Translational Research Programme, Department of Microbiology of Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Nimmi Baby
- Department of Physiology, National University of Singapore, Singapore, 117597, Singapore
| | - Huey Yee Teo
- Immunology Translational Research Programme, Department of Microbiology of Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Zuhairah Binte Hanafi
- Immunology Translational Research Programme, Department of Microbiology of Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Siti Nazihah Mohd Salleh
- Human Monoclonal Antibody Platform, Singapore Immunology Network (SIgN), Agency for Science, Technology and Research (A*STAR), Singapore, 138648, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, National University of Singapore, Singapore, 117597, Singapore.
- Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore, 117456, Singapore.
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore.
| | - Haiyan Liu
- Immunology Translational Research Programme, Department of Microbiology of Immunology, Yong Loo Lin School of Medicine, Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore.
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Zhang YY, Li XS, Ren KD, Peng J, Luo XJ. Restoration of metal homeostasis: a potential strategy against neurodegenerative diseases. Ageing Res Rev 2023; 87:101931. [PMID: 37031723 DOI: 10.1016/j.arr.2023.101931] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/04/2023] [Accepted: 04/06/2023] [Indexed: 04/11/2023]
Abstract
Metal homeostasis is critical to normal neurophysiological activity. Metal ions are involved in the development, metabolism, redox and neurotransmitter transmission of the central nervous system (CNS). Thus, disturbance of homeostasis (such as metal deficiency or excess) can result in serious consequences, including neurooxidative stress, excitotoxicity, neuroinflammation, and nerve cell death. The uptake, transport and metabolism of metal ions are highly regulated by ion channels. There is growing evidence that metal ion disorders and/or the dysfunction of ion channels contribute to the progression of neurodegenerative diseases, such as Alzheimer's disease (AD), Parkinson's disease (PD), amyotrophic lateral sclerosis (ALS), and multiple sclerosis (MS). Therefore, metal homeostasis-related signaling pathways are emerging as promising therapeutic targets for diverse neurological diseases. This review summarizes recent advances in the studies regarding the physiological and pathophysiological functions of metal ions and their channels, as well as their role in neurodegenerative diseases. In addition, currently available metal ion modulators and in vivo quantitative metal ion imaging methods are also discussed. Current work provides certain recommendations based on literatures and in-depth reflections to improve neurodegenerative diseases. Future studies should turn to crosstalk and interactions between different metal ions and their channels. Concomitant pharmacological interventions for two or more metal signaling pathways may offer clinical advantages in treating the neurodegenerative diseases.
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Affiliation(s)
- Yi-Yue Zhang
- Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410078, China
| | - Xi-Sheng Li
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha 410013,China
| | - Kai-Di Ren
- Department of Pharmacy, The First Affiliated Hospital of Zhengzhou University, Zhengzhou 450052, China
| | - Jun Peng
- Department of Pharmacology, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410078, China; Hunan Provincial Key Laboratory of Cardiovascular Research, Xiangya School of Pharmaceutical Sciences, Central South University, Changsha 410078, China.
| | - Xiu-Ju Luo
- Department of Laboratory Medicine, The Third Xiangya Hospital of Central South University, Changsha 410013,China.
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Pavon MV, Navakkode S, Wong LW, Sajikumar S. Inhibition of Nogo-A rescues synaptic plasticity and associativity in APP/PS1 animal model of Alzheimer's disease. Semin Cell Dev Biol 2023; 139:111-120. [PMID: 35431138 DOI: 10.1016/j.semcdb.2022.04.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 03/30/2022] [Accepted: 04/06/2022] [Indexed: 12/31/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss and cognitive decline. Synaptic impairment is one of the first events to occur in the progression of this disease. Synaptic plasticity and cellular association of various plastic events have been shown to be affected in AD models. Nogo-A, a well-known axonal growth inhibitor with a recently discovered role as a plasticity suppressor, and its main receptor Nogo-66 receptor 1 (NGR1) have been found to be overexpressed in the hippocampus of Alzheimer's patients. However, the role of Nogo-A and its receptor in the pathology of AD is still widely unknown. In this work we set out to investigate whether Nogo-A is working as a plasticity suppressor in AD. Our results show that inhibition of the Nogo-A pathway via the Nogo-R antibody in an Alzheimer's mouse model, APP/PS1, leads to the restoration of both synaptic plasticity and associativity in a protein synthesis and NMDR-dependent manner. We also show that inhibition of the p75NTR pathway, which is strongly associated with NGR1, restores synaptic plasticity as well. Mechanistically, we propose that the restoration of synaptic plasticity in APP/PS1 via inhibition of the Nogo-A pathway is due to the modulation of the RhoA-ROCK2 pathway and increase in plasticity related proteins. Our study identifies Nogo-A as a plasticity suppressor in AD models hence targeting Nogo-A could be a promising strategy to understanding AD pathology.
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Affiliation(s)
- Maria Vazquez Pavon
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology Programme, National University of Singapore, Singapore 117456, Singapore
| | - Sheeja Navakkode
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore 308232, Singapore
| | - Lik-Wei Wong
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology Programme, National University of Singapore, Singapore 117456, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117597, Singapore; Life Sciences Institute, Neurobiology Programme, National University of Singapore, Singapore 117456, Singapore; Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 117456, Singapore.
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Pramio DT, Vieceli FM, Varella-Branco E, Goes CP, Kobayashi GS, da Silva Pelegrina DV, de Moraes BC, El Allam A, De Kumar B, Jara G, Farfel JM, Bennett DA, Kundu S, Viapiano MS, Reis EM, de Oliveira PSL, Dos Santos E Passos-Bueno MR, Rothlin CV, Ghosh S, Schechtman D. DNA methylation of the promoter region at the CREB1 binding site is a mechanism for the epigenetic regulation of brain-specific PKMζ. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2023; 1866:194909. [PMID: 36682583 PMCID: PMC10037092 DOI: 10.1016/j.bbagrm.2023.194909] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 01/05/2023] [Accepted: 01/13/2023] [Indexed: 01/21/2023]
Abstract
Protein kinase M zeta, PKMζ, is a brain enriched kinase with a well characterized role in Long-Term Potentiation (LTP), the activity-dependent strengthening of synapses involved in long-term memory formation. However, little is known about the molecular mechanisms that maintain the tissue specificity of this kinase. Here, we characterized the epigenetic factors, mainly DNA methylation, regulating PKMζ expression in the human brain. The PRKCZ gene has an upstream promoter regulating Protein kinase C ζ (PKCζ), and an internal promoter driving PKMζ expression. A demethylated region, including a canonical CREB binding site, situated at the internal promoter was only observed in human CNS tissues. The induction of site-specific hypermethylation of this region resulted in decreased CREB1 binding and downregulation of PKMζ expression. Noteworthy, CREB binding sites were absent in the upstream promoter of PRKCZ locus, suggesting a specific mechanism for regulating PKMζ expression. These observations were validated using a system of human neuronal differentiation from induced pluripotent stem cells (iPSCs). CREB1 binding at the internal promoter was detected only in differentiated neurons, where PKMζ is expressed. The same epigenetic mechanism in the context of CREB binding site was identified in other genes involved in neuronal differentiation and LTP. Additionally, aberrant DNA hypermethylation at the internal promoter was observed in cases of Alzheimer's disease, correlating with decreased expression of PKMζ in patient brains. Altogether, we present a conserved epigenetic mechanism regulating PKMζ expression and other genes enhanced in the CNS with possible implications in neuronal differentiation and Alzheimer's disease.
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Affiliation(s)
| | | | | | - Carolina Purcell Goes
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, SP, Brazil; Laboratory of Neuromodulation of Experimental Pain, Department of Anatomy, Institute of Biomedical Sciences, University of Sao Paulo, SP, Brazil
| | | | | | | | - Aicha El Allam
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA
| | | | - Gabriel Jara
- Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian National Biosciences Laboratory (LNBio) Campinas, SP, Brazil
| | - José Marcelo Farfel
- Traumatology and Orthopedy Department, Faculdade de Medicina, Universidade de São Paulo, SP, Brazil; Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA; Health Sciences Program, Instituto de Assistência Medica ao Servidor Público do Estado (IAMSPE), SP, Brazil
| | - David Alan Bennett
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Somanath Kundu
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Mariano S Viapiano
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY, USA
| | - Eduardo Moraes Reis
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, SP, Brazil
| | - Paulo Sergio Lopes de Oliveira
- Brazilian Center for Research in Energy and Materials (CNPEM), Brazilian National Biosciences Laboratory (LNBio) Campinas, SP, Brazil
| | | | - Carla V Rothlin
- Department of Immunobiology, Yale School of Medicine, New Haven, CT, USA; Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA
| | - Sourav Ghosh
- Department of Neurology, Yale School of Medicine, New Haven, CT, USA; Department of Pharmacology, Yale School of Medicine, New Haven, CT, USA.
| | - Deborah Schechtman
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, SP, Brazil.
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Hydroxychloroquine lowers Alzheimer's disease and related dementias risk and rescues molecular phenotypes related to Alzheimer's disease. Mol Psychiatry 2023; 28:1312-1326. [PMID: 36577843 PMCID: PMC10005941 DOI: 10.1038/s41380-022-01912-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 12/03/2022] [Accepted: 12/07/2022] [Indexed: 12/29/2022]
Abstract
We recently nominated cytokine signaling through the Janus-kinase-signal transducer and activator of transcription (JAK/STAT) pathway as a potential AD drug target. As hydroxychloroquine (HCQ) has recently been shown to inactivate STAT3, we hypothesized that it may impact AD pathogenesis and risk. Among 109,124 rheumatoid arthritis patients from routine clinical care, HCQ initiation was associated with a lower risk of incident AD compared to methotrexate initiation across 4 alternative analyses schemes addressing specific types of biases including informative censoring, reverse causality, and outcome misclassification (hazard ratio [95% confidence interval] of 0.92 [0.83-1.00], 0.87 [0.81-0.93], 0.84 [0.76-0.93], and 0.87 [0.75-1.01]). We additionally show that HCQ exerts dose-dependent effects on late long-term potentiation (LTP) and rescues impaired hippocampal synaptic plasticity prior to significant accumulation of amyloid plaques and neurodegeneration in APP/PS1 mice. Additionally, HCQ treatment enhances microglial clearance of Aβ1-42, lowers neuroinflammation, and reduces tau phosphorylation in cell culture-based phenotypic assays. Finally, we show that HCQ inactivates STAT3 in microglia, neurons, and astrocytes suggesting a plausible mechanism associated with its observed effects on AD pathogenesis. HCQ, a relatively safe and inexpensive drug in current use may be a promising disease-modifying AD treatment. This hypothesis merits testing through adequately powered clinical trials in at-risk individuals during preclinical stages of disease progression.
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Rahman M, Bose S, Chakrabartty S. On-device synaptic memory consolidation using Fowler-Nordheim quantum-tunneling. Front Neurosci 2023; 16:1050585. [PMID: 36711131 PMCID: PMC9880265 DOI: 10.3389/fnins.2022.1050585] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2022] [Accepted: 12/28/2022] [Indexed: 01/15/2023] Open
Abstract
Introduction For artificial synapses whose strengths are assumed to be bounded and can only be updated with finite precision, achieving optimal memory consolidation using primitives from classical physics leads to synaptic models that are too complex to be scaled in-silico. Here we report that a relatively simple differential device that operates using the physics of Fowler-Nordheim (FN) quantum-mechanical tunneling can achieve tunable memory consolidation characteristics with different plasticity-stability trade-offs. Methods A prototype FN-synapse array was fabricated in a standard silicon process and was used to verify the optimal memory consolidation characteristics and used for estimating the parameters of an FN-synapse analytical model. The analytical model was then used for large-scale memory consolidation and continual learning experiments. Results We show that compared to other physical implementations of synapses for memory consolidation, the operation of the FN-synapse is near-optimal in terms of the synaptic lifetime and the consolidation properties. We also demonstrate that a network comprising FN-synapses outperforms a comparable elastic weight consolidation (EWC) network for some benchmark continual learning tasks. Discussions With an energy footprint of femtojoules per synaptic update, we believe that the proposed FN-synapse provides an ultra-energy-efficient approach for implementing both synaptic memory consolidation and continual learning on a physical device.
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Broadbelt T, Mutlu-Smith M, Carnicero-Senabre D, Saido TC, Saito T, Wang SH. Impairment in novelty-promoted memory via behavioral tagging and capture before apparent memory loss in a knock-in model of Alzheimer's disease. Sci Rep 2022; 12:22298. [PMID: 36566248 PMCID: PMC9789965 DOI: 10.1038/s41598-022-26113-1] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2022] [Accepted: 12/09/2022] [Indexed: 12/25/2022] Open
Abstract
Alzheimer's disease (AD) is associated with cognitive impairments and age-dependent memory deficits which have been studied using genetic models of AD. Whether the processes for modulating memory persistence are more vulnerable to the influence of amyloid pathology than the encoding and consolidation of the memory remains unclear. Here, we investigated whether early amyloid pathology would affect peri-learning novelty in promoting memory, through a process called behavioral tagging and capture (BTC). AppNL-G-F/NL-G-F mice and wild-type littermates were trained in an appetitive delayed matching-to-place (ADMP) task which allows for the assessment of peri-learning novelty in facilitating memory. The results show that novelty enabled intermediate-term memory in wild-type mice, but not in AppNL-G-F/NL-G-F mice in adulthood. This effect preceded spatial memory impairment in the ADMP task seen in middle age. Other memory tests in the Barnes maze, Y-maze, novel object or location recognition tasks remained intact. Together, memory modulation through BTC is impaired before apparent deficits in learning and memory. Relevant biological mechanisms underlying BTC and the implication in AD are discussed.
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Affiliation(s)
- Tabitha Broadbelt
- grid.4305.20000 0004 1936 7988Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
| | - Menekse Mutlu-Smith
- grid.4305.20000 0004 1936 7988Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
| | - Daniel Carnicero-Senabre
- grid.4305.20000 0004 1936 7988Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK ,grid.5515.40000000119578126Present Address: Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Instituto de Investigación Sanitaria La Paz (IdiPaz), Department of Biochemistry and Instituto de Investigaciones Biomédicas Alberto Sols UAM-CSIC, Faculty of Medicine, Autonomous University of Madrid, Madrid, Spain
| | - Takaomi C. Saido
- grid.474690.8Laboratory for Proteolytic Neuroscience, RIKEN Brain Science Institute, Saitama, 351-0198 Japan
| | - Takashi Saito
- grid.260433.00000 0001 0728 1069Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Sciences, Aichi, 467-8601 Japan
| | - Szu-Han Wang
- grid.4305.20000 0004 1936 7988Centre for Clinical Brain Sciences, The University of Edinburgh, Chancellor’s Building, 49 Little France Crescent, Edinburgh, EH16 4SB UK
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12
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Singh AK, Neo SH, Liwang C, Pang KKL, Leng JCK, Sinha SH, Shetty MS, Vasudevan M, Rao VJ, Joshi I, Eswaramoorthy M, Pavon MV, Sheila AR, Navakkode S, Kundu TK, Sajikumar S. Glucose derived carbon nanosphere (CSP) conjugated TTK21, an activator of the histone acetyltransferases CBP/p300, ameliorates amyloid-beta 1-42 induced deficits in plasticity and associativity in hippocampal CA1 pyramidal neurons. Aging Cell 2022; 21:e13675. [PMID: 35962576 PMCID: PMC9470894 DOI: 10.1111/acel.13675] [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: 12/03/2019] [Revised: 06/16/2022] [Accepted: 07/04/2022] [Indexed: 01/25/2023] Open
Abstract
The master epigenetic regulator lysine acetyltransferase (KAT) p300/CBP plays a pivotal role in neuroplasticity and cognitive functions. Recent evidence has shown that in several neurodegenerative diseases, including Alzheimer's disease (AD), the expression level and function of p300/CBP are severely compromised, leading to altered gene expression causing pathological conditions. Here, we show that p300/CBP activation by a small-molecule TTK21, conjugated to carbon nanosphere (CSP) ameliorates Aβ-impaired long-term potentiation (LTP) induced by high-frequency stimulation, theta burst stimulation, and synaptic tagging/capture (STC). This functional rescue was correlated with CSP-TTK21-induced changes in transcription and translation. Mechanistically, we observed that the expression of a large number of synaptic plasticity- and memory-related genes was rescued, presumably by the restoration of p300/CBP mediated acetylation. Collectively, these results suggest that small-molecule activators of p300/CBP could be a potential therapeutic molecule for neurodegenerative diseases like AD.
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Affiliation(s)
- Akash K. Singh
- Transcription and Disease Laboratory, Molecular Biology and Genetics UnitJawaharlal Nehru Centre for Advanced Scientific ResearchBengaluruIndia
| | - Sin H. Neo
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
| | - Christine Liwang
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
| | - Karen K. L. Pang
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
| | - Jason C. K. Leng
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
| | - Sarmistha H. Sinha
- Transcription and Disease Laboratory, Molecular Biology and Genetics UnitJawaharlal Nehru Centre for Advanced Scientific ResearchBengaluruIndia
| | - Mahesh S. Shetty
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore,Lee Kong Chian School of Medicine, Nanyang Technological UniversitySingaporeSingapore
| | - Madavan Vasudevan
- Department of Neuroscience and PharmacologyIowa Neuroscience Institute, Carver College of Medicine, University of IowaIowa CityIowaUSA
| | - Vinay J. Rao
- Transcription and Disease Laboratory, Molecular Biology and Genetics UnitJawaharlal Nehru Centre for Advanced Scientific ResearchBengaluruIndia
| | - Ila Joshi
- Transcription and Disease Laboratory, Molecular Biology and Genetics UnitJawaharlal Nehru Centre for Advanced Scientific ResearchBengaluruIndia
| | | | - Maria V. Pavon
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
| | - Ang R. Sheila
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
| | - Sheeja Navakkode
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore,Chemistry and Physics of Materials UnitJawaharlal Nehru Centre for Advanced Scientific ResearchBengaluruIndia
| | - Tapas K. Kundu
- Transcription and Disease Laboratory, Molecular Biology and Genetics UnitJawaharlal Nehru Centre for Advanced Scientific ResearchBengaluruIndia,Division of Neuroscience and Aging BiologyCSIR‐Central Drug Research Institute Sector 10LucknowUttar PradeshIndia
| | - Sreedharan Sajikumar
- Department of PhysiologyYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore,Life Science Institute Neurobiology Programme (LSI)National University of SingaporeSingaporeSingapore,Healthy Longevity Translational Research ProgrammeYong Loo Lin School of Medicine, National University of SingaporeSingaporeSingapore
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13
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Upregulation of IP 3 receptor mediates APP-induced defects in synaptic downscaling and sleep homeostasis. Cell Rep 2022; 38:110594. [PMID: 35354048 DOI: 10.1016/j.celrep.2022.110594] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2021] [Revised: 12/14/2021] [Accepted: 03/09/2022] [Indexed: 11/22/2022] Open
Abstract
Evidence suggests that impaired synaptic and firing homeostasis represents a driving force of early Alzheimer's disease (AD) progression. Here, we examine synaptic and sleep homeostasis in a Drosophila model by overexpressing human amyloid precursor protein (APP), whose duplication and mutations cause familial early-onset AD. We find that APP overexpression induces synaptic hyperexcitability. RNA-seq data indicate exaggerated expression of Ca2+-related signaling genes in APP mutants, including genes encoding Dmca1D, calcineurin (CaN) complex, and IP3R. We further demonstrate that increased CaN activity triggers transcriptional activation of Itpr (IP3R) through activating nuclear factor of activated T cells (NFAT). Strikingly, APP overexpression causes defects in synaptic downscaling and sleep deprivation-induced sleep rebound, and both defects could be restored by inhibiting IP3R. Our findings uncover IP3R as a shared signaling molecule in synaptic downscaling and sleep homeostasis, and its dysregulation may lead to synaptic hyperexcitability and AD progression at early stage.
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14
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Duffau H. Introducing the concept of brain metaplasticity in glioma: how to reorient the pattern of neural reconfiguration to optimize the therapeutic strategy. J Neurosurg 2022; 136:613-617. [PMID: 34624858 DOI: 10.3171/2021.5.jns211214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Hugues Duffau
- 1Department of Neurosurgery, Gui de Chauliac Hospital, Montpellier University Medical Center; Team "Neuroplasticity, Stem Cells and Glial Tumors," Institute of Functional Genomics, INSERM U-1191, University of Montpellier; and University of Montpellier, France
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15
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Lopes CR, Amaral IM, Pereira MF, Lopes JP, Madeira D, Canas PM, Cunha RA, Agostinho P. Impact of blunting astrocyte activity on hippocampal synaptic plasticity in a mouse model of early Alzheimer's disease based on amyloid-β peptide exposure. J Neurochem 2022; 160:556-567. [PMID: 35043392 DOI: 10.1111/jnc.15575] [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: 11/17/2021] [Revised: 12/27/2021] [Accepted: 01/12/2022] [Indexed: 11/27/2022]
Abstract
Amyloid-β peptides (Aβ) accumulate in the brain since early Alzheimer's disease (AD) and dysregulate hippocampal synaptic plasticity, the neurophysiological basis of memory. Although the relationship between long-term potentiation (LTP) and memory processes is well established, there is also evidence that long-term depression (LTD) may be crucial for learning and memory. Alterations in synaptic plasticity, namely in LTP, can be due to communication failures between astrocytes and neurons; however, little is known about astrocytes´ ability to control hippocampal LTD, particularly in AD-like conditions. We now aimed to test the involvement of astrocytes in changes of hippocampal LTP and LTD triggered by Aβ1-42 , taking advantage of L-α-aminoadipate (L-AA), a gliotoxin that blunts astrocytic function. The effects of Aβ1-42 exposure was tested in two different experimental paradigms: ex vivo (hippocampal slices superfusion) and in vivo (intracerebroventricular injection), which were previously validated to impair memory and hippocampal synaptic plasticity, two features of early AD. Blunting astrocytic function with L-AA reduced LTP and LTD amplitude in hippocampal slices from control mice but the effect on LTD was less evident, suggesting that astrocytes have a greater influence on LTP than on LTD under non-pathological conditions. However, under AD conditions, blunting astrocytes did not consistently alter the reduction of LTP magnitude and reverted the LTD-to-LTP shift caused by both ex vivo and in vivo Aβ1-42 exposure. This shows that astrocytes were responsible for the hippocampal LTD-to-LTP shift observed in early AD conditions, reinforcing the interest of strategies targeting astrocytes to restore memory and synaptic plasticity deficits present in early AD.
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Affiliation(s)
- Cátia R Lopes
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
| | - Inês M Amaral
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal
| | | | - João P Lopes
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal
| | - Daniela Madeira
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
| | - Paula M Canas
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal
| | - Rodrigo A Cunha
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
| | - Paula Agostinho
- Center for Neuroscience and Cell Biology, CNC, Coimbra, Portugal.,Faculty of Medicine, University of Coimbra, FMUC, Portugal
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16
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Jeremic D, Jiménez-Díaz L, Navarro-López JD. Past, present and future of therapeutic strategies against amyloid-β peptides in Alzheimer's disease: a systematic review. Ageing Res Rev 2021; 72:101496. [PMID: 34687956 DOI: 10.1016/j.arr.2021.101496] [Citation(s) in RCA: 120] [Impact Index Per Article: 40.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 09/30/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most prevalent neurodegenerative disease in ageing, affecting around 46 million people worldwide but few treatments are currently available. The etiology of AD is still puzzling, and new drugs development and clinical trials have high failure rates. Urgent outline of an integral (multi-target) and effective treatment of AD is needed. Accumulation of amyloid-β (Aβ) peptides is considered one of the fundamental neuropathological pillars of the disease, and its dyshomeostasis has shown a crucial role in AD onset. Therefore, many amyloid-targeted therapies have been investigated. Here, we will systematically review recent (from 2014) investigational, follow-up and review studies focused on anti-amyloid strategies to summarize and analyze their current clinical potential. Combination of anti-Aβ therapies with new developing early detection biomarkers and other therapeutic agents acting on early functional AD changes will be highlighted in this review. Near-term approval seems likely for several drugs acting against Aβ, with recent FDA approval of a monoclonal anti-Aβ oligomers antibody -aducanumab- raising hopes and controversies. We conclude that, development of oligomer-epitope specific Aβ treatment and implementation of multiple improved biomarkers and risk prediction methods allowing early detection, together with therapies acting on other factors such as hyperexcitability in early AD, could be the key to slowing this global pandemic.
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17
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Arnaud K, Oliveira Moreira V, Vincent J, Dallerac G, Dubreuil C, Dupont E, Richter M, Müller UC, Rondi-Reig L, Prochiantz A, Di Nardo AA. Choroid plexus APP regulates adult brain proliferation and animal behavior. Life Sci Alliance 2021; 4:4/11/e202000703. [PMID: 34544751 PMCID: PMC8473726 DOI: 10.26508/lsa.202000703] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2020] [Revised: 09/08/2021] [Accepted: 09/08/2021] [Indexed: 12/02/2022] Open
Abstract
Adult mouse choroid plexus shows elevated APP expression. sAPPα secreted into the CSF modulates neurogenic niche proliferation, whereas choroid plexus expression of fAD APP mutants leads to reduced niche proliferation, deficits in hippocampus synaptic plasticity, and learning defects. Elevated amyloid precursor protein (APP) expression in the choroid plexus suggests an important role for extracellular APP metabolites such as sAPPα in cerebrospinal fluid. Despite widespread App brain expression, we hypothesized that specifically targeting choroid plexus expression could alter animal physiology. Through various genetic and viral approaches in the adult mouse, we show that choroid plexus APP levels significantly impact proliferation in both subventricular zone and hippocampus dentate gyrus neurogenic niches. Given the role of Aβ peptides in Alzheimer disease pathogenesis, we also tested whether favoring the production of Aβ in choroid plexus could negatively affect niche functions. After AAV5-mediated long-term expression of human mutated APP specifically in the choroid plexus of adult wild-type mice, we observe reduced niche proliferation, reduced hippocampus APP expression, behavioral defects in reversal learning, and deficits in hippocampal long-term potentiation. Our findings highlight the unique role played by the choroid plexus in regulating brain function and suggest that targeting APP in choroid plexus may provide a means to improve hippocampus function and alleviate disease-related burdens.
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Affiliation(s)
- Karen Arnaud
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Centre National de Recherche Scientifique (CNRS) UMR7241, INSERM U1050, Labex MemoLife, PSL Research University, Paris, France
| | - Vanessa Oliveira Moreira
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Centre National de Recherche Scientifique (CNRS) UMR7241, INSERM U1050, Labex MemoLife, PSL Research University, Paris, France
| | - Jean Vincent
- Neuroscience Paris Seine, Institut de Biologie Paris Seine (IBPS), Sorbonne Université, CNRS, INSERM, Labex BioPsy, ENP Foundation, Sorbonne University, Paris, France
| | - Glenn Dallerac
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Centre National de Recherche Scientifique (CNRS) UMR7241, INSERM U1050, Labex MemoLife, PSL Research University, Paris, France
| | - Chantal Dubreuil
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Centre National de Recherche Scientifique (CNRS) UMR7241, INSERM U1050, Labex MemoLife, PSL Research University, Paris, France
| | - Edmond Dupont
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Centre National de Recherche Scientifique (CNRS) UMR7241, INSERM U1050, Labex MemoLife, PSL Research University, Paris, France
| | - Max Richter
- Ruprecht-Karls University Heidelberg, Institute of Pharmacy and Molecular Biotechnology, Functional Genomics, Heidelberg, Germany
| | - Ulrike C Müller
- Ruprecht-Karls University Heidelberg, Institute of Pharmacy and Molecular Biotechnology, Functional Genomics, Heidelberg, Germany
| | - Laure Rondi-Reig
- Neuroscience Paris Seine, Institut de Biologie Paris Seine (IBPS), Sorbonne Université, CNRS, INSERM, Labex BioPsy, ENP Foundation, Sorbonne University, Paris, France
| | - Alain Prochiantz
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Centre National de Recherche Scientifique (CNRS) UMR7241, INSERM U1050, Labex MemoLife, PSL Research University, Paris, France
| | - Ariel A Di Nardo
- Centre for Interdisciplinary Research in Biology (CIRB), Collège de France, Centre National de Recherche Scientifique (CNRS) UMR7241, INSERM U1050, Labex MemoLife, PSL Research University, Paris, France
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18
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Djebari S, Iborra-Lázaro G, Temprano-Carazo S, Sánchez-Rodríguez I, Nava-Mesa MO, Múnera A, Gruart A, Delgado-García JM, Jiménez-Díaz L, Navarro-López JD. G-Protein-Gated Inwardly Rectifying Potassium (Kir3/GIRK) Channels Govern Synaptic Plasticity That Supports Hippocampal-Dependent Cognitive Functions in Male Mice. J Neurosci 2021; 41:7086-7102. [PMID: 34261700 PMCID: PMC8372024 DOI: 10.1523/jneurosci.2849-20.2021] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 05/11/2021] [Accepted: 06/04/2021] [Indexed: 01/17/2023] Open
Abstract
The G-protein-gated inwardly rectifying potassium (Kir3/GIRK) channel is the effector of many G-protein-coupled receptors (GPCRs). Its dysfunction has been linked to the pathophysiology of Down syndrome, Alzheimer's and Parkinson's diseases, psychiatric disorders, epilepsy, drug addiction, or alcoholism. In the hippocampus, GIRK channels decrease excitability of the cells and contribute to resting membrane potential and inhibitory neurotransmission. Here, to elucidate the role of GIRK channels activity in the maintenance of hippocampal-dependent cognitive functions, their involvement in controlling neuronal excitability at different levels of complexity was examined in C57BL/6 male mice. For that purpose, GIRK activity in the dorsal hippocampus CA3-CA1 synapse was pharmacologically modulated by two drugs: ML297, a GIRK channel opener, and Tertiapin-Q (TQ), a GIRK channel blocker. Ex vivo, using dorsal hippocampal slices, we studied the effect of pharmacological GIRK modulation on synaptic plasticity processes induced in CA1 by Schaffer collateral stimulation. In vivo, we performed acute intracerebroventricular (i.c.v.) injections of the two GIRK modulators to study their contribution to electrophysiological properties and synaptic plasticity of dorsal hippocampal CA3-CA1 synapse, and to learning and memory capabilities during hippocampal-dependent tasks. We found that pharmacological disruption of GIRK channel activity by i.c.v. injections, causing either function gain or function loss, induced learning and memory deficits by a mechanism involving neural excitability impairments and alterations in the induction and maintenance of long-term synaptic plasticity processes. These results support the contention that an accurate control of GIRK activity must take place in the hippocampus to sustain cognitive functions.SIGNIFICANCE STATEMENT Cognitive processes of learning and memory that rely on hippocampal synaptic plasticity processes are critically ruled by a finely tuned neural excitability. G-protein-gated inwardly rectifying K+ (GIRK) channels play a key role in maintaining resting membrane potential, cell excitability and inhibitory neurotransmission. Here, we demonstrate that modulation of GIRK channels activity, causing either function gain or function loss, transforms high-frequency stimulation (HFS)-induced long-term potentiation (LTP) into long-term depression (LTD), inducing deficits in hippocampal-dependent learning and memory. Together, our data show a crucial GIRK-activity-mediated mechanism that governs synaptic plasticity direction and modulates subsequent hippocampal-dependent cognitive functions.
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Affiliation(s)
- Souhail Djebari
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
| | - Guillermo Iborra-Lázaro
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
| | - Sara Temprano-Carazo
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
| | - Irene Sánchez-Rodríguez
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
| | - Mauricio O Nava-Mesa
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
- Neuroscience Research Group (NEUROS), Universidad del Rosario, Bogotá, Colombia 111711
| | - Alejandro Múnera
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
- Behavioral Neurophysiology Laboratory, Universidad Nacional de Colombia, Bogotá, Colombia 111321
| | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, Seville, Spain 41013
| | | | - Lydia Jiménez-Díaz
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
| | - Juan D Navarro-López
- University of Castilla-La Mancha, NeuroPhysiology & Behavior Laboratory, Centro Regional de Investigaciones Biomédicas, Facultad de Medicina de Ciudad Real, Spain 13071
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19
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Han JLT, Pang KKL, Ang SRX, Sharma M, Sajikumar S. Inhibition of lysine methyltransferase G9a/GLP reinstates long-term synaptic plasticity and synaptic tagging/capture by facilitating protein synthesis in the hippocampal CA1 area of APP/PS1 mouse model of Alzheimer's disease. Transl Neurodegener 2021; 10:23. [PMID: 34187583 PMCID: PMC8329750 DOI: 10.1186/s40035-021-00247-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 06/14/2021] [Indexed: 11/10/2022] Open
Affiliation(s)
- Javan Lee Tze Han
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Karen Ka Lam Pang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Sheila Rui Xia Ang
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Mahima Sharma
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore.,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117597, Singapore. .,Neurobiology Programme, Life Sciences Institute, National University of Singapore, Singapore, 117456, Singapore. .,Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 117456, Singapore.
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20
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Bin Ibrahim MZ, Benoy A, Sajikumar S. Long-term plasticity in the hippocampus: maintaining within and 'tagging' between synapses. FEBS J 2021; 289:2176-2201. [PMID: 34109726 DOI: 10.1111/febs.16065] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2021] [Revised: 05/15/2021] [Accepted: 06/01/2021] [Indexed: 12/11/2022]
Abstract
Synapses between neurons are malleable biochemical structures, strengthening and diminishing over time dependent on the type of information they receive. This phenomenon known as synaptic plasticity underlies learning and memory, and its different forms, long-term potentiation (LTP) and long-term depression (LTD), perform varied cognitive roles in reinforcement, relearning and associating memories. Moreover, both LTP and LTD can exist in an early transient form (early-LTP/LTD) or a late persistent form (late-LTP/LTD), which are triggered by different induction protocols, and also differ in their dependence on protein synthesis and the involvement of key molecular players. Beyond homosynaptic modifications, synapses can also interact with one another. This is encapsulated in the synaptic tagging and capture hypothesis (STC), where synapses expressing early-LTP/LTD present a 'tag' that can capture the protein synthesis products generated during a temporally proximal late-LTP/LTD induction. This 'tagging' phenomenon forms the framework of synaptic interactions in various conditions and accounts for the cellular basis of the time-dependent associativity of short-lasting and long-lasting memories. All these synaptic modifications take place under controlled neuronal conditions, regulated by subcellular elements such as epigenetic regulation, proteasomal degradation and neuromodulatory signals. Here, we review current understanding of the different forms of synaptic plasticity and its regulatory mechanisms in the hippocampus, a brain region critical for memory formation. We also discuss expression of plasticity in hippocampal CA2 area, a long-overlooked narrow hippocampal subfield and the behavioural correlate of STC. Lastly, we put forth perspectives for an integrated view of memory representation in synapses.
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Affiliation(s)
- Mohammad Zaki Bin Ibrahim
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore
| | - Amrita Benoy
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore.,Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
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21
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Sundman MH, Lim K, Ton That V, Mizell JM, Ugonna C, Rodriguez R, Chen NK, Fuglevand AJ, Liu Y, Wilson RC, Fellous JM, Rapcsak S, Chou YH. Transcranial magnetic stimulation reveals diminished homoeostatic metaplasticity in cognitively impaired adults. Brain Commun 2020; 2:fcaa203. [PMID: 33376989 PMCID: PMC7750948 DOI: 10.1093/braincomms/fcaa203] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2020] [Revised: 09/22/2020] [Accepted: 10/13/2020] [Indexed: 12/13/2022] Open
Abstract
Homoeostatic metaplasticity is a neuroprotective physiological feature that counterbalances Hebbian forms of plasticity to prevent network destabilization and hyperexcitability. Recent animal models highlight dysfunctional homoeostatic metaplasticity in the pathogenesis of Alzheimer's disease. However, the association between homoeostatic metaplasticity and cognitive status has not been systematically characterized in either demented or non-demented human populations, and the potential value of homoeostatic metaplasticity as an early biomarker of cognitive impairment has not been explored in humans. Here, we report that, through pre-conditioning the synaptic activity prior to non-invasive brain stimulation, the association between homoeostatic metaplasticity and cognitive status could be established in a population of non-demented human subjects (older adults across cognitive spectrums; all within the non-demented range). All participants (n = 40; age range, 65-74, 47.5% female) underwent a standardized neuropsychological battery, magnetic resonance imaging and a transcranial magnetic stimulation protocol. Specifically, we sampled motor-evoked potentials with an input/output curve immediately before and after repetitive transcranial magnetic stimulation to assess neural plasticity with two experimental paradigms: one with voluntary muscle contraction (i.e. modulated synaptic activity history) to deliberately introduce homoeostatic interference, and one without to serve as a control condition. From comparing neuroplastic responses across these experimental paradigms and across cohorts grouped by cognitive status, we found that (i) homoeostatic metaplasticity is diminished in our cohort of cognitively impaired older adults and (ii) this neuroprotective feature remains intact in cognitively normal participants. This novel finding suggests that (i) future studies should expand their scope beyond just Hebbian forms of plasticity that are traditionally assessed when using non-invasive brain stimulation to investigate cognitive ageing and (ii) the potential value of homoeostatic metaplasticity in serving as a biomarker for cognitive impairment should be further explored.
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Affiliation(s)
- Mark H Sundman
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
| | - Koeun Lim
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
| | - Viet Ton That
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
| | | | - Chidi Ugonna
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721, USA
- Department of Medical Imaging, University of Arizona, Tucson, AZ 85721, USA
| | - Rudolph Rodriguez
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
| | - Nan-Kuei Chen
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721, USA
- Department of Medical Imaging, University of Arizona, Tucson, AZ 85721, USA
| | - Andrew J Fuglevand
- Department of Physiology, College of Medicine, University of Arizona, Tucson, AZ 85721, USA
- Department of Neuroscience, College of Medicine, University of Arizona, Tucson, AZ 85721, USA
| | - Yilin Liu
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
| | - Robert C Wilson
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
| | - Jean-Marc Fellous
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
- Department of Biomedical Engineering, University of Arizona, Tucson, AZ 85721, USA
| | - Steven Rapcsak
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
- Department of Neurology, University of Arizona, Tucson, AZ 85721, USA
| | - Ying-Hui Chou
- Department of Psychology, University of Arizona, Tucson, AZ 85721, USA
- Evelyn F. McKnight Brain Institute, Arizona Center on Aging, and BIO5 Institute, University of Arizona, Tucson, AZ 85721, USA
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22
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Wang JKT. Uniting homeostatic plasticity and exosome biology: A revision of the conceptual framework for drug discovery in neurodegenerative diseases? ADVANCES IN PHARMACOLOGY 2020; 90:277-306. [PMID: 33706937 DOI: 10.1016/bs.apha.2020.10.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/29/2023]
Abstract
Neurodegenerative diseases (NDDs) are in need of new drug discovery approaches. Our previous systematic analyses of Huntington's Disease (HD) literature for protein-protein interactors (PPIs) and modifiers of mutant Huntingtin-driven phenotypes revealed enrichment for PPIs of genes required for homeostatic synaptic plasticity (HSP) and exosome (EV) function and exosomal proteins, which in turn highly overlapped each other and with PPIs of genes associated with other NDDs. We proposed that HSP and EVs are linked to each other and are also involved in NDD pathophysiology. Recent studies showed that HSP is indeed altered in HD and AD, and that presynaptic homeostatic plasticity in motoneurons compensates for ALS pathology. Eliminating it causes earlier degeneration and death. If this holds true in other NDDs, drug discovery in animal models should then include elucidation of homeostatic compensation that either masks phenotypes of physiologically expressed mutant genes or are overridden by their overexpression. In this new conceptual framework, enhancing such underlying homeostatic compensation forms the basis for novel therapeutic strategies to slow progression of NDDs. Moreover, if EVs are linked to HSP, then their ability to penetrate the brain, target cell types, deliver miRNA and other molecules can be leveraged to develop attractive drug modalities. Testing this new framework is posed as four questions on model development and mechanistic studies progressing from higher throughput platforms to mouse models. Similar approaches may apply to other CNS disorders including schizophrenia, autism, Rett and Fragile X syndromes due to potential links of their susceptibility genes to HSP and EVs.
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23
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Ho WY, Navakkode S, Liu F, Soong TW, Ling SC. Deregulated expression of a longevity gene, Klotho, in the C9orf72 deletion mice with impaired synaptic plasticity and adult hippocampal neurogenesis. Acta Neuropathol Commun 2020; 8:155. [PMID: 32887666 PMCID: PMC7473815 DOI: 10.1186/s40478-020-01030-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 08/29/2020] [Indexed: 01/17/2023] Open
Abstract
Hexanucleotide repeat expansion of C9ORF72 is the most common genetic cause of amyotrophic lateral sclerosis and frontotemporal dementia. Synergies between loss of C9ORF72 functions and gain of toxicities from the repeat expansions contribute to C9ORF72-mediated pathogenesis. However, how loss of C9orf72 impacts neuronal and synaptic functions remains undetermined. Here, we showed that long-term potentiation at the dentate granule cells and long-term depression at the Schaffer collateral/commissural synapses at the area CA1 were reduced in the hippocampus of C9orf72 knockout mice. Using unbiased transcriptomic analysis, we identified that Klotho, a longevity gene, was selectively dysregulated in an age-dependent manner. Specifically, Klotho protein expression in the hippocampus of C9orf72 knockout mice was incorrectly enriched in the dendritic regions of CA1 with concomitant reduction in granule cell layer of dentate gyrus at 3-month of age followed by an accelerating decline during aging. Furthermore, adult hippocampal neurogenesis was reduced in C9orf72 knockout mice. Taken together, our data suggest that C9ORF72 is required for synaptic plasticity and adult neurogenesis in the hippocampus and Klotho deregulations may be part of C9ORF72-mediated toxicity.
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24
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Latif-Hernandez A, Sabanov V, Ahmed T, Craessaerts K, Saito T, Saido T, Balschun D. The two faces of synaptic failure in App NL-G-F knock-in mice. Alzheimers Res Ther 2020; 12:100. [PMID: 32838792 PMCID: PMC7445922 DOI: 10.1186/s13195-020-00667-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 08/10/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND Intensive basic and preclinical research into Alzheimer's disease (AD) has yielded important new findings, but they could not yet been translated into effective therapies. One of the reasons is the lack of animal models that sufficiently reproduce the complexity of human AD and the response of human brain circuits to novel treatment approaches. As a step in overcoming these limitations, new App knock-in models have been developed that avoid transgenic APP overexpression and its associated side effects. These mice are proposed to serve as valuable models to examine Aß-related pathology in "preclinical AD." METHODS Since AD as the most common form of dementia progresses into synaptic failure as a major cause of cognitive deficits, the detailed characterization of synaptic dysfunction in these new models is essential. Here, we addressed this by extracellular and whole-cell patch-clamp recordings in AppNL-G-F mice compared to AppNL animals which served as controls. RESULTS We found a beginning synaptic impairment (LTP deficit) at 3-4 months in the prefrontal cortex of AppNL-G-F mice that is further aggravated and extended to the hippocampus at 6-8 months. Measurements of miniature EPSCs and IPSCs point to a marked increase in excitatory and inhibitory presynaptic activity, the latter accompanied by a moderate increase in postsynaptic inhibitory function. CONCLUSIONS Our data reveal a marked impairment of primarily postsynaptic processes at the level of synaptic plasticity but the dominance of a presumably compensatory presynaptic upregulation at the level of elementary miniature synaptic function.
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Affiliation(s)
- Amira Latif-Hernandez
- Brain and Cognition, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium
- Present Address: Neurology and Neurological Sciences, Stanford Medicine, Stanford, USA
| | - Victor Sabanov
- Brain and Cognition, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium
- Leuven Brain Institute, KU Leuven, Leuven, Belgium
| | - Tariq Ahmed
- Brain and Cognition, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium
- Present Address: Qatar Biomedical Research Institute, Ar-Rayyan, Qatar
| | - Katleen Craessaerts
- Leuven Brain Institute, KU Leuven, Leuven, Belgium
- Laboratory for the Research of Neurodegenerative Diseases, VIB Center for the Biology of Disease, Leuven, Belgium
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
- Present Address: Department of Neurocognitive Science, Nagoya City University Graduate School of Medical Science, Nagoya, Aichi, Japan
| | - Takaomi Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako-shi, Saitama, Japan
| | - Detlef Balschun
- Brain and Cognition, KU Leuven, Tiensestraat 102, Box 3714, 3000, Leuven, Belgium.
- Leuven Brain Institute, KU Leuven, Leuven, Belgium.
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25
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Mayordomo-Cava J, Iborra-Lázaro G, Djebari S, Temprano-Carazo S, Sánchez-Rodríguez I, Jeremic D, Gruart A, Delgado-García JM, Jiménez-Díaz L, Navarro-López JD. Impairments of Synaptic Plasticity Induction Threshold and Network Oscillatory Activity in the Hippocampus Underlie Memory Deficits in a Non-Transgenic Mouse Model of Amyloidosis. BIOLOGY 2020; 9:biology9070175. [PMID: 32698467 PMCID: PMC7407959 DOI: 10.3390/biology9070175] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/09/2020] [Revised: 07/07/2020] [Accepted: 07/17/2020] [Indexed: 12/20/2022]
Abstract
In early Alzheimer disease (AD) models synaptic failures and upstreaming aberrant patterns of network synchronous activity result in hippocampal-dependent memory deficits. In such initial stage, soluble forms of Amyloid-β (Aβ) peptides have been shown to play a causal role. Among different Aβ species, Aβ25-35 has been identified as the biologically active fragment, as induces major neuropathological signs related to early AD stages. Consequently, it has been extensively used to acutely explore the pathophysiological events related with neuronal dysfunction induced by soluble Aβ forms. However, the synaptic mechanisms underlying its toxic effects on hippocampal-dependent memory remain unresolved. Here, in an in vivo model of amyloidosis generated by intracerebroventricular injections of Aβ25-35 we studied the synaptic dysfunction mechanisms underlying hippocampal cognitive deficits. At the synaptic level, long-term potentiation (LTP) of synaptic excitation and inhibition was induced in CA1 region by high frequency simulation (HFS) applied to Schaffer collaterals. Aβ25-35 was found to alter metaplastic mechanisms of plasticity, facilitating long-term depression (LTD) of both types of LTP. In addition, aberrant synchronization of hippocampal network activity was found while at the behavioral level, deficits in hippocampal-dependent habituation and recognition memories emerged. Together, our results provide a substrate for synaptic disruption mechanism underlying hippocampal cognitive deficits present in Aβ25-35 amyloidosis model.
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Affiliation(s)
- Jennifer Mayordomo-Cava
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Guillermo Iborra-Lázaro
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Souhail Djebari
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Sara Temprano-Carazo
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Irene Sánchez-Rodríguez
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Danko Jeremic
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
| | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, 41013 Seville, Spain; (A.G.); (J.M.D.-G.)
| | | | - Lydia Jiménez-Díaz
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
- Correspondence: (L.J.-D.); (J.D.N.-L.)
| | - Juan D. Navarro-López
- Neurophysiology and Behavioral Lab, Centro Regional de Investigaciones Biomédicas, School of Medicine of Ciudad Real, University of Castilla-La Mancha, 13071 Ciudad Real, Spain; (J.M.-C.); (G.I.-L.); (S.D.); (S.T.-C.); (I.S.-R.); (D.J.)
- Correspondence: (L.J.-D.); (J.D.N.-L.)
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26
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Nagappan PG, Chen H, Wang DY. Neuroregeneration and plasticity: a review of the physiological mechanisms for achieving functional recovery postinjury. Mil Med Res 2020; 7:30. [PMID: 32527334 PMCID: PMC7288425 DOI: 10.1186/s40779-020-00259-3] [Citation(s) in RCA: 36] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Accepted: 05/24/2020] [Indexed: 12/12/2022] Open
Abstract
Neuronal networks, especially those in the central nervous system (CNS), evolved to support extensive functional capabilities while ensuring stability. Several physiological "brakes" that maintain the stability of the neuronal networks in a healthy state quickly become a hinderance postinjury. These "brakes" include inhibition from the extracellular environment, intrinsic factors of neurons and the control of neuronal plasticity. There are distinct differences between the neuronal networks in the peripheral nervous system (PNS) and the CNS. Underpinning these differences is the trade-off between reduced functional capabilities with increased adaptability through the formation of new connections and new neurons. The PNS has "facilitators" that stimulate neuroregeneration and plasticity, while the CNS has "brakes" that limit them. By studying how these "facilitators" and "brakes" work and identifying the key processes and molecules involved, we can attempt to apply these theories to the neuronal networks of the CNS to increase its adaptability. The difference in adaptability between the CNS and PNS leads to a difference in neuroregenerative properties and plasticity. Plasticity ensures quick functional recovery of abilities in the short and medium term. Neuroregeneration involves synthesizing new neurons and connections, providing extra resources in the long term to replace those damaged by the injury, and achieving a lasting functional recovery. Therefore, by understanding the factors that affect neuroregeneration and plasticity, we can combine their advantages and develop rehabilitation techniques. Rehabilitation training methods, coordinated with pharmacological interventions and/or electrical stimulation, contributes to a precise, holistic treatment plan that achieves functional recovery from nervous system injuries. Furthermore, these techniques are not limited to limb movement, as other functions lost as a result of brain injury, such as speech, can also be recovered with an appropriate training program.
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Affiliation(s)
| | - Hong Chen
- Shengli Clinical College of Fujian Medical University; Department of Neurology, Fujian Provincial Hospital, Fuzhou, Fujian, 350001, China.
| | - De-Yun Wang
- Department of Otolaryngology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, 119228, Singapore
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27
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Krishna-K K, Baby N, Raghuraman R, Navakkode S, Behnisch T, Sajikumar S. Regulation of aberrant proteasome activity re-establishes plasticity and long-term memory in an animal model of Alzheimer's disease. FASEB J 2020; 34:9466-9479. [PMID: 32459037 DOI: 10.1096/fj.201902844rr] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2019] [Revised: 04/17/2020] [Accepted: 05/05/2020] [Indexed: 11/11/2022]
Abstract
Reduced retrograde memory performance at the cognitive level and aggregation/deposition of amyloid beta (Aβ) in the brain at the cellular level are some of the hallmarks of Alzheimer's Disease (AD). A molecular system that participates in the removal of proteins with an altered conformation is the Ubiquitin-Proteasome System (UPS). Impairments of the UPS in wild-type (WT) mice lead to defective clearance of Aβ and prevent long-term plasticity of synaptic transmission. Here we show data whereby in contrast to WT mice, the inhibition of proteasome-mediated protein degradation in an animal model of AD by MG132 or lactacystin restores impaired activity-dependent synaptic plasticity and its associative interaction, synaptic tagging and capture (STC) in vitro, as well as associative long-term memory in vivo. This augmentation of synaptic plasticity and memory is mediated by the mTOR pathway and protein synthesis. Our data offer novel insights into the rebalancing of proteins relevant for synaptic plasticity which are regulated by UPS in AD-like animal models. In addition, the data provide evidence that proteasome inhibitors might be effective in reinstating synaptic plasticity and memory performance in AD, and therefore offer a new potential therapeutic option for AD treatment.
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Affiliation(s)
- Kumar Krishna-K
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore, Singapore
| | - Nimmi Baby
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore, Singapore
| | - Radha Raghuraman
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore, Singapore
| | - Sheeja Navakkode
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Thomas Behnisch
- Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Fudan University, Shanghai, China
| | - Sreedharan Sajikumar
- Department of Physiology, National University of Singapore, Singapore, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore, Singapore
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28
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Wong LW, Chong YS, Wong WLE, Sajikumar S. Inhibition of Histone Deacetylase Reinstates Hippocampus-Dependent Long-Term Synaptic Plasticity and Associative Memory in Sleep-Deprived Mice. Cereb Cortex 2020; 30:4169-4182. [PMID: 32188968 DOI: 10.1093/cercor/bhaa041] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Sleep plays an important role in the establishment of long-term memory; as such, lack of sleep severely impacts domains of our health including cognitive function. Epigenetic mechanisms regulate gene transcription and protein synthesis, playing a critical role in the modulation of long-term synaptic plasticity and memory. Recent evidences indicate that transcriptional dysregulation as a result of sleep deprivation (SD) may contribute to deficits in plasticity and memory function. The histone deacetylase inhibitor suberoylanilide hydroxamic acid (SAHA), also known as Vorinostat, a clinically approved drug for human use, has been shown to ameliorate cognitive deficits in several neurological disease models. To further explore the therapeutic effect of SAHA, we have examined its potential role in improving the SD-mediated impairments in long-term plasticity, associative plasticity, and associative memory. Here we show that SAHA preserves long-term plasticity, associative plasticity, and associative memory in SD hippocampus. Furthermore, we find that SAHA prevents SD-mediated epigenetic changes by upregulating histone acetylation, hence preserving the ERK-cAMP-responsive element-binding protein (CREB)/CREB-binding protein-brain-derived neurotrophic factor pathway in the hippocampus. These data demonstrate that modifying epigenetic mechanisms via SAHA can prevent or reverse impairments in long-term plasticity and memory that result from sleep loss. Thus, SAHA could be a potential therapeutic agent in improving SD-related memory deficits.
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Affiliation(s)
- Lik-Wei Wong
- Department of Physiology, National University of Singapore, Singapore 117597, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore 117 456, Singapore
| | - Yee Song Chong
- Department of Physiology, National University of Singapore, Singapore 117597, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore 117 456, Singapore
| | - Win Lee Edwin Wong
- Department of Physiology, National University of Singapore, Singapore 117597, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore 117 456, Singapore
| | - Sreedharan Sajikumar
- Department of Physiology, National University of Singapore, Singapore 117597, Singapore.,Life Sciences Institute Neurobiology Programme, National University of Singapore, Singapore 117 456, Singapore
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29
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Srivastava A, Das B, Yao AY, Yan R. Metabotropic Glutamate Receptors in Alzheimer's Disease Synaptic Dysfunction: Therapeutic Opportunities and Hope for the Future. J Alzheimers Dis 2020; 78:1345-1361. [PMID: 33325389 PMCID: PMC8439550 DOI: 10.3233/jad-201146] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by the presence of neuritic plaques and neurofibrillary tangles. The impaired synaptic plasticity and dendritic loss at the synaptic level is an early event associated with the AD pathogenesis. The abnormal accumulation of soluble oligomeric amyloid-β (Aβ), the major toxic component in amyloid plaques, is viewed to trigger synaptic dysfunctions through binding to several presynaptic and postsynaptic partners and thus to disrupt synaptic transmission. Over time, the abnormalities in neural transmission will result in cognitive deficits, which are commonly manifested as memory loss in AD patients. Synaptic plasticity is regulated through glutamate transmission, which is mediated by various glutamate receptors. Here we review recent progresses in the study of metabotropic glutamate receptors (mGluRs) in AD cognition. We will discuss the role of mGluRs in synaptic plasticity and their modulation as a possible strategy for AD cognitive improvement.
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Affiliation(s)
- Akriti Srivastava
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Brati Das
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Annie Y. Yao
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
| | - Riqiang Yan
- Department of Neuroscience, University of Connecticut Health, Farmington, CT, USA
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30
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Tsokas P, Rivard B, Hsieh C, Cottrell JE, Fenton AA, Sacktor TC. Antisense Oligodeoxynucleotide Perfusion Blocks Gene Expression of Synaptic Plasticity-related Proteins without Inducing Compensation in Hippocampal Slices. Bio Protoc 2019; 9:e3387. [PMID: 31803793 PMCID: PMC6892586 DOI: 10.21769/bioprotoc.3387] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2019] [Revised: 08/29/2019] [Accepted: 08/26/2019] [Indexed: 12/14/2022] Open
Abstract
The elucidation of the molecular mechanisms of long-term synaptic plasticity has been hindered by both the compensation that can occur after chronic loss of the core plasticity molecules and by ex vivo conditions that may not reproduce in vivo plasticity. Here we describe a novel method to rapidly suppress gene expression by antisense oligodeoxynucleotides (ODNs) applied to rodent brain slices in an "Oslo-type" interface chamber. The method has three advantageous features: 1) rapid blockade of new synthesis of the targeted proteins that avoids genetic compensation, 2) efficient oxygenation of the brain slice, which is critical for reproducing in vivo conditions of long-term synaptic plasticity, and 3) a recirculation system that uses only small volumes of bath solution (< 5 ml), reducing the amount of reagents required for long-term experiments lasting many hours. The method employs a custom-made recirculation system involving piezoelectric micropumps and was first used for the acute translational blockade of protein kinase Mζ (PKMζ) synthesis during long-term potentiation (LTP) by Tsokas et al., 2016. In that study, applying antisense-ODN rapidly prevents the synthesis of PKMζ and blocks late-LTP without inducing the compensation by other protein kinase C (PKC) isoforms that occurs in PKCζ/PKMζ knockout mice. In addition, we show that in a low-oxygenation submersion-type chamber, applications of the atypical PKC inhibitor, zeta inhibitory peptide (ZIP), can result in unstable baseline synaptic transmission, but in the high-oxygenation, "Oslo-type" interface electrophysiology chamber, the drug reverses late-LTP without affecting baseline synaptic transmission. This comparison reveals that the interface chamber, but not the submersion chamber, reproduces the effects of ZIP in vivo. Therefore, the protocol combines the ability to acutely block new synthesis of specific proteins for the study of long-term synaptic plasticity, while maintaining properties of synaptic transmission that reproduce in vivo conditions relevant for long-term memory.
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Affiliation(s)
- Panayiotis Tsokas
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
- Department of Anesthesiology, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Bruno Rivard
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - Changchi Hsieh
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
| | - James E. Cottrell
- Department of Anesthesiology, State University of New York Downstate Medical Center, Brooklyn, United States
| | - André Antonio Fenton
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
- Center for Neural Science, New York University, New York, United States
| | - Todd Charlton Sacktor
- Department of Physiology and Pharmacology, The Robert F. Furchgott Center for Neural and Behavioral Science, State University of New York Downstate Medical Center, Brooklyn, United States
- Department of Anesthesiology, State University of New York Downstate Medical Center, Brooklyn, United States
- Department of Neurology, State University of New York Downstate Medical Center, Brooklyn, United States
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31
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Elevated levels of Secreted-Frizzled-Related-Protein 1 contribute to Alzheimer's disease pathogenesis. Nat Neurosci 2019; 22:1258-1268. [PMID: 31308530 DOI: 10.1038/s41593-019-0432-1] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2018] [Accepted: 05/20/2019] [Indexed: 02/07/2023]
Abstract
The deposition of aggregated amyloid-β peptides derived from the pro-amyloidogenic processing of the amyloid precurson protein (APP) into characteristic amyloid plaques (APs) is distinctive to Alzheimer's disease (AD). Alternative APP processing via the metalloprotease ADAM10 prevents amyloid-β formation. We tested whether downregulation of ADAM10 activity by its secreted endogenous inhibitor secreted-frizzled-related protein 1 (SFRP1) is a common trait of sporadic AD. We demonstrate that SFRP1 is significantly increased in the brain and cerebrospinal fluid of patients with AD, accumulates in APs and binds to amyloid-β, hindering amyloid-β protofibril formation. Sfrp1 overexpression in an AD-like mouse model anticipates the appearance of APs and dystrophic neurites, whereas its genetic inactivation or the infusion of α-SFRP1-neutralizing antibodies favors non-amyloidogenic APP processing. Decreased Sfrp1 function lowers AP accumulation, improves AD-related histopathological traits and prevents long-term potentiation loss and cognitive deficits. Our study unveils SFRP1 as a crucial player in AD pathogenesis and a promising AD therapeutic target.
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32
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Zhao F, Siu JJ, Huang W, Askwith C, Cao L. Insulin Modulates Excitatory Synaptic Transmission and Synaptic Plasticity in the Mouse Hippocampus. Neuroscience 2019; 411:237-254. [PMID: 31146008 PMCID: PMC6612444 DOI: 10.1016/j.neuroscience.2019.05.033] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Revised: 05/14/2019] [Accepted: 05/16/2019] [Indexed: 12/17/2022]
Abstract
The administration of exogenous insulin into the hippocampus has the potential to enhance cognitive function and exert other beneficial effects. Elucidating the neurobiological substrates of insulin action and its underlying physiological mechanisms may further improve treatment efficacy. Previous work has shown that insulin affects synaptic plasticity, however there are discrepancies and contradictory conclusions between studies. Here, we used extracellular field recordings in mouse hippocampal slices to investigate how insulin acutely modulates synaptic transmission and synaptic plasticity, both of which are correlated with learning and memory processes. Our data demonstrate that insulin application inhibited basal excitatory synaptic transmission and promoted long-term potentiation (LTP) induction at hippocampal Schaffer collateral-CA1 synapses. Under similar conditions, insulin strongly activated the PI3K/AKT pathway, but had only a weak effect on the MAPK/ERK pathway. Although insulin-induced inhibition of field excitatory post-synaptic potentials (fEPSPs) was previously termed insulin-long-term depression (insulin-LTD), insulin application potentiated recovery from classically induced LTD. Further analysis suggests suppression of presynaptic neurotransmitter release contributed to the insulin-LTD. At low concentrations, insulin primarily inhibited fEPSPs; however, at high concentration, its effects were of mixed inhibition and enhancement in different recordings. Moreover, a broad spectrum protein kinase C blocker, cannabinoid receptor type 1 activator, or a high glucose concentration inhibited fEPSPs per se, and disturbed insulin's effect on fEPSP. Insulin also caused depotentiation during LTP expression and triggered depression during LTD recovery. Given the essential roles of dynamic synaptic transmission and plasticity in learning and memory, our data provide more evidence that insulin application may actively modulate hippocampal-dependent cognitive events.
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Affiliation(s)
- Fangli Zhao
- College of Medicine, The Ohio State University
| | - Jason J Siu
- College of Medicine, The Ohio State University
| | - Wei Huang
- College of Medicine, The Ohio State University
| | | | - Lei Cao
- College of Medicine, The Ohio State University.
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33
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Zhao P, Qian X, Nie Y, Sun N, Wang Z, Wu J, Wei C, Ma R, Wang Z, Chai G, Li Y. Neuropeptide S Ameliorates Cognitive Impairment of APP/PS1 Transgenic Mice by Promoting Synaptic Plasticity and Reducing Aβ Deposition. Front Behav Neurosci 2019; 13:138. [PMID: 31293402 PMCID: PMC6603143 DOI: 10.3389/fnbeh.2019.00138] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Accepted: 06/06/2019] [Indexed: 12/02/2022] Open
Abstract
Alzheimer’s disease (AD) is a devastating disease in the elderly with no known effective treatment. It is characterized by progressive deterioration of memory and cognition. Many new potential targets are being investigated to develop effective therapeutic strategies for AD. Neuropeptide S (NPS) is an endogenous peptide in the central nervous system, which has been shown to play a beneficial role in learning and memory. However, whether NPS can ameliorate cognitive deficits in AD remains unclear. In this study, we examined the effects of NPS treatment on the cognitive behaviors and pathological hallmarks in 8-month-old APPswe/PS1dE9 (APP/PS1) AD mice. We found that the APP/PS1 mice exhibited lower levels of NPS receptors (NPSRs) in the hippocampal area, and NPS administration increased c-Fos expression in the hippocampus and cortex, which suggests the NPS/NPSR system may contribute to the pathogenesis of AD. After an intracerebroventricular injection of NPS (1 nmol) for 2 weeks, we found NPS treatment ameliorated spatial memory deficits and promoted dendrite ramification and spine generation in hippocampal CA1 neurons, which was accompanied by the upregulation of postsynaptic density protein 95 (PSD95) and synapsin1. We also demonstrated that the injection of NPS decreased Aβ plaque deposits by decreasing the γ-secretase activity and the phosphorylation of APP at Thr668. Furthermore, application of NPS reversed the deficits in hippocampal late-phase long-term potentiation (LTP). These findings suggest NPS attenuated cognitive deficits by reducing pathological features in APP/PS1 mice, and NPS might be a potential therapeutic agent for AD.
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Affiliation(s)
- Peng Zhao
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Xiaohang Qian
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Yunjuan Nie
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Na Sun
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | | | - Jiajun Wu
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Chen Wei
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Ruikun Ma
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Zhe Wang
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Gaoshang Chai
- Wuxi Medical School, Jiangnan University, Wuxi, China
| | - Yuqing Li
- Wuxi Medical School, Jiangnan University, Wuxi, China.,Department of Neurology, College of Medicine, University of Florida, Gainesville, FL, United States
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Yousef M, Babür E, Delibaş S, Tan B, Çimen A, Dursun N, Süer C. Adult-Onset Hypothyroidism Alters the Metaplastic Properties of Dentate Granule Cells by Decreasing Akt Phosphorylation. J Mol Neurosci 2019; 68:647-657. [PMID: 31069661 DOI: 10.1007/s12031-019-01323-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2018] [Accepted: 04/22/2019] [Indexed: 12/15/2022]
Abstract
The expression of homosynaptic long-term depression (LTD) governs the subsequent induction of long-term potentiation (LTP) at hippocampal synapses. This process, called metaplasticity, is associated with a transient increase in the levels of several kinases, such as extracellular signal-regulated protein kinases 1/2 (ERK1/2), c-Jun N-terminal kinase (JNK), and Akt kinase. It has been increasingly realized that the chemical changes in the hippocampus caused by hypothyroidism may be the key underlying causes of the learning deficits, memory loss, and impaired LTP associated with this disease. However, the functional role of thyroid hormones in the "plasticity of synaptic plasticity" has only begun to be elucidated. To address this issue, we sought to determine whether the administration of 6-n-propyl-2-thiouracil (PTU) alters the relationship between priming and the induction of subsequent LTP and related signaling molecules. The activation of ERK1/2, JNK, and Akt was measured in the hippocampus at least 95 min after priming onset. We found that priming stimulation at 5 Hz for 3 s negatively impacted the induction of LTP by subsequent tetanic stimulation in hypothyroid animals, as manifested by a more rapid decrease in the fEPSP slope and population spike amplitude. This phenomenon was accompanied by lower levels of phosphorylated Akt in the surgically removed hippocampus of the hypothyroid rats compared to the euthyroid rats. The metaplastic response and the expression of these proteins in the 1-Hz-primed hippocampus were not different between the two groups. These observations suggest that decreased PI3K/Akt signaling may be involved in the compromised metaplastic regulation of LTP observed in hypothyroidism, which may account for the learning difficulties/cognitive impairments associated with this condition.
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Affiliation(s)
- Marwa Yousef
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Ercan Babür
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Sumeyra Delibaş
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Burak Tan
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Ayşenur Çimen
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Nurcan Dursun
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey
| | - Cem Süer
- Physiology department of Medicine, University of Erciyes, Kayseri, Turkey.
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Tyrtyshnaia A, Manzhulo I, Kipryushina Y, Ermolenko E. Neuroinflammation and adult hippocampal neurogenesis in neuropathic pain and alkyl glycerol ethers treatment in aged mice. Int J Mol Med 2019; 43:2153-2163. [PMID: 30896810 PMCID: PMC6445594 DOI: 10.3892/ijmm.2019.4142] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Accepted: 03/18/2019] [Indexed: 12/20/2022] Open
Abstract
Neuropathic pain is a condition characterized by unpleasant sensory and emotional experiences associated with a number of diseases or injuries affecting the sensory system through various mechanisms. In this study, we focused on the impact of chronic neuropathic pain on the microglial state and hippocampal neurogenesis in aged mice. In addition, we examined the effects of alkyl glycerol ethers (AGE) treatment on behavioral parameters, hippocampal neuronal and microglial plasticity in aged C57BL/6 mice with neuropathic pain. For the induction of neuropathic pain, we used the model of chronic constriction injury (CCI) of the sciatic nerve. We observed painful behavior in animals subjected to CCI, expressed as a decrease in locomotor activity and the development of cold allodynia. A violation of working and long‑term memory was also observed. AGE administration reduced the severity of cold allodynia and prevented memory impairment. In addition to behavioral changes, neuropathic pain was accompanied by microglial activation, changes in the hippocampal production of pro‑ and anti‑inflammatory cytokines, as well as a decrease in neurogenesis. The administration of AGE prevented the neuropathic pain‑derived effects, including M1 microglial activation and neurogenesis disruption. However, in vitro experiments demonstrated the pro‑inflammatory activation of microglial cells, emphasizing the complexity of the mechanisms underlying the pharmacological effects of AGE. On the whole, the findings of this study demonstrate that AGE treatment prevented behavioral effects of neuropathic pain in mice, and AGE may thus have potential for use in the prevention or treatment of neuropathic pain cognitive and emotional effects. However, as the mechanisms underlying this type of pain are complex, further studies are required to determine the detailed pharmacological effects of AGE.
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Affiliation(s)
- Anna Tyrtyshnaia
- 'A.V. Zhirmunsky National Scientific Center of Marine Biology', Far Eastern Branch of the Russian Academy of Sciences, 690041 Vladivostok, Russia
| | - Igor Manzhulo
- 'A.V. Zhirmunsky National Scientific Center of Marine Biology', Far Eastern Branch of the Russian Academy of Sciences, 690041 Vladivostok, Russia
| | - Yulia Kipryushina
- 'A.V. Zhirmunsky National Scientific Center of Marine Biology', Far Eastern Branch of the Russian Academy of Sciences, 690041 Vladivostok, Russia
| | - Ekaterina Ermolenko
- 'A.V. Zhirmunsky National Scientific Center of Marine Biology', Far Eastern Branch of the Russian Academy of Sciences, 690041 Vladivostok, Russia
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Synaptopodin Deficiency Ameliorates Symptoms in the 3xTg Mouse Model of Alzheimer's Disease. J Neurosci 2019; 39:3983-3992. [PMID: 30872324 DOI: 10.1523/jneurosci.2920-18.2019] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2018] [Revised: 01/18/2019] [Accepted: 02/18/2019] [Indexed: 11/21/2022] Open
Abstract
Disruption in calcium homeostasis is linked to several pathologies and is suggested to play a pivotal role in the cascade of events leading to Alzheimer's disease (AD). Synaptopodin (SP) residing in dendritic spines has been associated with ryanodine receptor (RyR), such that spines lacking SP release less calcium from stores. In this work, we mated SPKO with 3xTg mice (3xTg/SPKO) to test the effect of SP deficiency in the AD mouse. We found that 6-month-old male 3xTg/SPKO mice restored normal spatial learning in the Barns maze, LTP in hippocampal slices, and expression levels of RyR in the hippocampus that were altered in the 3xTg mice. In addition, there was a marked reduction in 3xTg-associated phosphorylated tau, amyloid β plaques, and activated microglia in 3xTg/SPKO male and female mice. These experiments indicate that a reduction in the expression of SP ameliorates AD-associated phenotype in 3xTg mice.SIGNIFICANCE STATEMENT This study strengthens the proposed role of calcium stores in the development of AD-associated phenotype in the 3xTg mouse model, in that a genetic reduction of the functioning of ryanodine receptors using synaptopodin-knock-out mice ameliorates AD symptoms at the behavioral, electrophysiological, and morphological levels of analysis.
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Wang X, Zheng W. Ca 2+ homeostasis dysregulation in Alzheimer's disease: a focus on plasma membrane and cell organelles. FASEB J 2019; 33:6697-6712. [PMID: 30848934 DOI: 10.1096/fj.201801751r] [Citation(s) in RCA: 63] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Emerging evidence indicates that Ca2+ is a vital factor in modulating the pathogenesis of Alzheimer's disease (AD). In healthy neurons, Ca2+ concentration is balanced to maintain a lower level in the cytosol than in the extracellular space or certain intracellular compartments such as endoplasmic reticulum (ER) and the lysosome, whereas this homeostasis is broken in AD. On the plasma membrane, the AD hallmarks amyloid-β (Aβ) and tau interact with ligand-gated or voltage-gated Ca2+-influx channels and inhibit the Ca2+-efflux ATPase or exchangers, leading to an elevated intracellular Ca2+ level and disrupted Ca2+ signal. In the ER, the disabled presenilin "Ca2+ leak" function and the direct implications of Aβ and presenilin mutants contribute to Ca2+-signal disorder. The enhanced ryanodine receptor (RyR)-mediated and inositol 1,4,5-trisphosphate receptor (IP3R)-mediated Ca2+ release from the ER aggravates cytosolic Ca2+ disorder and triggers apoptosis; the down-regulated ER Ca2+ sensor, stromal interaction molecule (STIM), alleviates store-operated Ca2+ entry in plasma membrane, leading to spine loss. The increased transfer of Ca2+ from ER to mitochondria through mitochondria-associated ER membrane (MAM) causes Ca2+ overload in the mitochondrial matrix and consequently opens the cellular damage-related channel, mitochondrial permeability transition pore (mPTP). In this review, we discuss the effects of Aβ, tau and presenilin on neuronal Ca2+ signal, focusing on the receptors and regulators in plasma membrane and ER; we briefly introduce the involvement of MAM-mediated Ca2+ transfer and mPTP opening in AD pathogenesis.-Wang, X., Zheng, W. Ca2+ homeostasis dysregulation in Alzheimer's disease: a focus on plasma membrane and cell organelles.
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Affiliation(s)
- Xingjian Wang
- Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang, China
| | - Wei Zheng
- Department of Histology and Embryology, College of Basic Medical Science, China Medical University, Shenyang, China
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38
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Extinction of aversive taste memory homeostatically prevents the maintenance of in vivo insular cortex LTP: Calcineurin participation. Neurobiol Learn Mem 2018; 154:54-61. [DOI: 10.1016/j.nlm.2018.04.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2017] [Revised: 02/14/2018] [Accepted: 04/05/2018] [Indexed: 12/27/2022]
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39
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Nguyen PV, Gelinas JN. Noradrenergic gating of long-lasting synaptic potentiation in the hippocampus: from neurobiology to translational biomedicine. J Neurogenet 2018; 32:171-182. [DOI: 10.1080/01677063.2018.1497630] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023]
Affiliation(s)
- Peter V. Nguyen
- Department of Physiology and Institute of Neuroscience & Mental Health, University of Alberta School of Medicine, Edmonton, Canada
| | - Jennifer N. Gelinas
- Department of Neurology and Institute for Genomic Medicine, College of Physicians & Surgeons of Columbia University, New York, NY,USA
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Maggio N, Vlachos A. Tumor necrosis factor (TNF) modulates synaptic plasticity in a concentration-dependent manner through intracellular calcium stores. J Mol Med (Berl) 2018; 96:1039-1047. [PMID: 30073573 DOI: 10.1007/s00109-018-1674-1] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Revised: 07/22/2018] [Accepted: 07/23/2018] [Indexed: 12/11/2022]
Abstract
The role of inflammatory signaling pathways in synaptic plasticity has long been identified. Yet, it remains unclear how inflammatory cytokines assert their pleiotropic effects on neural plasticity. Moreover, the neuronal targets through which inflammatory cytokines assert their effects on plasticity remain not well-understood. In an attempt to learn more about the plasticity-modulating effects of the pro-inflammatory cytokine tumor necrosis factor (TNF), we used two-pathway long-term potentiation (LTP) experiments at Schaffer collateral-CA1 synapses to test for concentration-dependent effects of TNF on synaptic plasticity. We report that high concentrations of TNF (1 μg/mL) impair the ability of mouse CA1 pyramidal neurons to express synaptic plasticity without affecting baseline synaptic transmission and/or previously established LTP. Interestingly, 100 ng/mL of TNF has no apparent effect on LTP, while low concentrations (1 ng/mL) promote the ability of neurons to express LTP. These dose-dependent metaplastic effects of TNF are modulated by intracellular calcium stores: Pharmacological activation of intracellular calcium stores with ryanodine (10 μM) reverses the negative effects of TNF[high], and the plasticity-promoting effects of TNF[low] are blocked when intracellular calcium stores are depleted with thapsigargin (1 μM). Consistent with this result, TNF does not promote plasticity in synaptopodin-deficient preparations, which show deficits in neuronal calcium store-mediated synaptic plasticity. Thus, we propose that TNF mediates its pleiotropic effects on synaptic plasticity in a concentration-dependent manner through signaling pathways that are modulated by intracellular calcium stores and require the presence of synaptopodin. These results demonstrate that TNF can act as mediator of metaplasticity, which is of considerable relevance in the context of brain diseases associated with increased TNF levels and alterations in synaptic plasticity. KEY MESSAGES • TNF modulates the ability of neurons to express synaptic plasticity. • High concentrations of TNF impair synaptic plasticity. • Low concentrations of TNF improve synaptic plasticity. • TNF does not affect previously established long-term potentiation. • Plasticity effects of TNF are modulated by intracellular calcium stores.
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Affiliation(s)
- Nicola Maggio
- Department of Neurology and Sagol Center for Neurosciences, Sheba Medical Center, 52621, Ramat Gan, Israel. .,Department of Neurology, The Chaim Sheba Medical Center, 52621, Tel HaShomer, Israel. .,Talpiot Medical Leadership Program, The Chaim Sheba Medical Center, 52621, Tel HaShomer, Israel. .,Department of Neurology and Neurosurgery, Sackler Faculty of Medicine and Sagol School of Neuroscience, Tel Aviv University, 52621, Tel Aviv, Israel.
| | - Andreas Vlachos
- Department of Neuroanatomy, Institute of Anatomy and Cell Biology, Faculty of Medicine, University of Freiburg, 79104, Freiburg, Germany.
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Loss of Synaptic Tagging in the Anterior Cingulate Cortex after Tail Amputation in Adult Mice. J Neurosci 2018; 38:8060-8070. [PMID: 30054392 DOI: 10.1523/jneurosci.0444-18.2018] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2018] [Revised: 07/21/2018] [Accepted: 07/24/2018] [Indexed: 01/16/2023] Open
Abstract
Anterior cingulate cortex (ACC) is known to play important roles in key brain functions such as pain perception, cognition, and emotion. Different forms of homosynaptic plasticity such as long-term potentiation (LTP) and long-term depression have been studied in ACC synapses. However, heterosynaptic plasticity such as synaptic tagging has not been reported. Here, we demonstrate synaptic tagging in the ACC of adult male mice by using a 64-channel multielectrode array recording system. Weak theta burst stimulation (TBS), normally inducing early-phase LTP or No-LTP in most of the activated channels, produced late phase-LTP (L-LTP) in a majority of channels when a strong TBS was applied earlier to a separate input within a certain time window. Similar to hippocampus, synaptic tagging in the ACC depends on the synthesis of new proteins. Tail amputation-induced peripheral injury caused a loss of this heterosynaptic L-LTP and occluded strong TBS-evoked L-LTP as well. Together, we provide the first report of the synaptic tagging-like phenomenon in the ACC of adult mice, and the loss of synaptic tagging to amputation may contribute to injury-related cognitive changes and phantom limb sensation and pain.SIGNIFICANCE STATEMENT ACC is an important cortical region involved in many brain functions. Previous studies have dissected the molecular mechanism of multiple types of homosynaptic plasticity of ACC synapses. Here, we report a novel form of heterosynaptic plasticity occurring in the ACC. This newly identified, protein synthesis-dependent neocortical synaptic tagging is sensitive to peripheral tail amputation injury and may provide basic mechanisms for synaptic pathophysiology of phantom pain and related cognitive changes.
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Gros A, Wang SH. Behavioral tagging and capture: long-term memory decline in middle-aged rats. Neurobiol Aging 2018; 67:31-41. [PMID: 29609080 PMCID: PMC5964067 DOI: 10.1016/j.neurobiolaging.2018.02.023] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 02/02/2018] [Accepted: 02/24/2018] [Indexed: 02/07/2023]
Abstract
Decline in cognitive functions, including hippocampus-dependent spatial memory, is commonly observed at a later stage of aging (e.g., >20 months old in rodents) and typically studied after a discrete learning event. How normal aging, particularly at an early stage, affects the modulatory aspect of memory persistence is underinvestigated. Previous studies in young animals show that weak, fading memories can last longer if a modulating event, such as spatial novelty, is introduced around memory encoding. This is known as behavioral tagging and capture (BTC). Here, we investigated how early aging (10-13 months old) affects BTC in an appetitive delayed-matching-to-place task. We trained rats when they were young and middle aged and found that novelty facilitated long-term memory persistence in young but not in middle-aged rats. However, re-exposure to the encoded environment after learning improved memory persistence in middle-aged rats. BTC, combined with memory reactivation, facilitated memory persistence through reconsolidation. Our results point toward a weakened tagging and capture mechanism before reduction of plasticity-related proteins at an early stage of aging.
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Affiliation(s)
- Alexandra Gros
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland, UK
| | - Szu-Han Wang
- Centre for Clinical Brain Sciences, The University of Edinburgh, Edinburgh, Scotland, UK; Centre for Cognitive Ageing and Cognitive Epidemiology, The University of Edinburgh, Edinburgh, Scotland, UK.
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Altered function of neuronal L-type calcium channels in ageing and neuroinflammation: Implications in age-related synaptic dysfunction and cognitive decline. Ageing Res Rev 2018; 42:86-99. [PMID: 29339150 DOI: 10.1016/j.arr.2018.01.001] [Citation(s) in RCA: 41] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2017] [Revised: 01/10/2018] [Accepted: 01/11/2018] [Indexed: 12/29/2022]
Abstract
The rapid developments in science have led to an increase in human life expectancy and thus, ageing and age-related disorders/diseases have become one of the greatest concerns in the 21st century. Cognitive abilities tend to decline as we get older. This age-related cognitive decline is mainly attributed to aberrant changes in synaptic plasticity and neuronal connections. Recent studies show that alterations in Ca2+ homeostasis underlie the increased vulnerability of neurons to age-related processes like cognitive decline and synaptic dysfunctions. Dysregulation of Ca2+ can lead to dramatic changes in neuronal functions. We discuss in this review, the recent advances on the potential role of dysregulated Ca2+ homeostasis through altered function of L-type voltage gated Ca2+ channels (LTCC) in ageing, with an emphasis on cognitive decline. This review therefore focuses on age-related changes mainly in the hippocampus, and with mention of other brain areas, that are important for learning and memory. This review also highlights age-related memory deficits via synaptic alterations and neuroinflammation. An understanding of these mechanisms will help us formulate strategies to reverse or ameliorate age-related disorders like cognitive decline.
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Edelmann E, Lessmann V. Dopaminergic innervation and modulation of hippocampal networks. Cell Tissue Res 2018; 373:711-727. [PMID: 29470647 DOI: 10.1007/s00441-018-2800-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2017] [Accepted: 01/17/2018] [Indexed: 02/06/2023]
Abstract
The catecholamine dopamine plays an important role in hippocampus-dependent plasticity and related learning and memory processes. Dopamine secretion in the hippocampus is activated by, e.g., salient or novel stimuli, thereby helping to establish and to stabilize hippocampus-dependent memories. Disturbed dopaminergic function in the hippocampus leads to severe pathophysiological conditions. While the role and importance of dopaminergic modulation of hippocampal networks have been unequivocally proven, there is still a lack of detailed molecular and cellular mechanistic understanding of how dopamine orchestrates these hippocampal processes. In this chapter of the special issue "Hippocampal structure and function," we will discuss the current understanding of dopaminergic modulation of basal synaptic transmission and long-lasting, activity-dependent potentiation or depression.
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Affiliation(s)
- Elke Edelmann
- Institut für Physiologie, Otto-von-Guericke-Universität, Medizinische Fakultät, Leipziger Str. 44, 39120, Magdeburg, Germany. .,Center for Behavioral Brain Sciences, Otto-von-Guericke University, Universitätsplatz 2, 39106, Magdeburg, Germany.
| | - Volkmar Lessmann
- Institut für Physiologie, Otto-von-Guericke-Universität, Medizinische Fakultät, Leipziger Str. 44, 39120, Magdeburg, Germany. .,Center for Behavioral Brain Sciences, Otto-von-Guericke University, Universitätsplatz 2, 39106, Magdeburg, Germany.
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Revisiting metaplasticity: The roles of calcineurin and histone deacetylation in unlearning odor preference memory in rat pups. Neurobiol Learn Mem 2018; 154:62-69. [PMID: 29421612 DOI: 10.1016/j.nlm.2018.02.003] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Revised: 01/16/2018] [Accepted: 02/03/2018] [Indexed: 10/18/2022]
Abstract
Previous work has shown that 24 h duration odor preference learning, induced by one-trial training, generates a down-regulation of the GluN1 receptor in anterior piriform cortex at 3 h, and results in metaplastic unlearning if a second training trial is given at 3 h. The GluN1 receptor upregulates at 24 h so 24 h spaced training is highly effective in extending memory duration. The present study replicates the piriform cortex unlearning result in the olfactory bulb circuit and further studies the relationship between the initial training strength and its associated metaplastic effect. Intrabulbar infusions that block calcineurin or inhibit histone deacetylation normally produce extended days-long memory. If given during training, they are not associated with GluN1 downregulation at 3 h and do not recruit an unlearning process at that time. The two memory strengthening protocols do not appear to interact, but are also not synergistic. These outcomes argue that it is critical to understand the metaplastic effects of training in order to optimize training protocols in the service of either memory strengthening or of memory weakening.
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Substance P induces plasticity and synaptic tagging/capture in rat hippocampal area CA2. Proc Natl Acad Sci U S A 2017; 114:E8741-E8749. [PMID: 28973908 DOI: 10.1073/pnas.1711267114] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
The hippocampal area Cornu Ammonis (CA) CA2 is important for social interaction and is innervated by Substance P (SP)-expressing supramammillary (SuM) nucleus neurons. SP exerts neuromodulatory effects on pain processing and central synaptic transmission. Here we provide evidence that SP can induce a slowly developing NMDA receptor- and protein synthesis-dependent potentiation of synaptic transmission that can be induced not only at entorhinal cortical (EC)-CA2 synapses but also at long-term potentiation (LTP)-resistant Schaffer collateral (SC)-CA2 synapses. In addition, SP-induced potentiation of SC-CA2 synapses transforms a short-term potentiation of EC-CA2 synaptic transmission into LTP, consistent with the synaptic tagging and capture hypothesis. Interestingly, this SP-induced potentiation and associative interaction between the EC and SC inputs of CA2 neurons is independent of the GABAergic system. In addition, CaMKIV and PKMζ play a critical role in the SP-induced effects on SC-CA2 and EC-CA2 synapses. Thus, afferents from SuM neurons are ideally situated to prime CA2 synapses for the formation of long-lasting plasticity and associativity.
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