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O'connell A, Quinlan L, Kwakowsky A. β-amyloid's neurotoxic mechanisms as defined by in vitro microelectrode arrays: a review. Pharmacol Res 2024; 209:107436. [PMID: 39369863 DOI: 10.1016/j.phrs.2024.107436] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2024] [Revised: 09/12/2024] [Accepted: 09/24/2024] [Indexed: 10/08/2024]
Abstract
Alzheimer's disease is characterised by the aggregation of β-amyloid, a pathological feature believed to drive the neuronal loss and cognitive decline commonly seen in the disease. Given the growing prevalence of this progressive neurodegenerative disease, understanding the exact mechanisms underlying this process has become a top priority. Microelectrode arrays are commonly used for chronic, non-invasive recording of both spontaneous and evoked neuronal activity from diverse in vitro disease models and to evaluate therapeutic or toxic compounds. To date, microelectrode arrays have been used to investigate β-amyloids' toxic effects, β-amyloids role in specific pathological features and to assess pharmacological approaches to treat Alzheimer's disease. The versatility of microelectrode arrays means these studies use a variety of methods and investigate different disease models and brain regions. This review provides an overview of these studies, highlighting their disparities and presenting the status of the current literature. Despite methodological differences, the current literature indicates that β-amyloid has an inhibitory effect on synaptic plasticity and induces network connectivity disruptions. β-amyloid's effect on spontaneous neuronal activity appears more complex. Overall, the literature corroborates the theory that β-amyloid induces neurotoxicity, having a progressive deleterious effect on neuronal signalling and plasticity. These studies also confirm that microelectrode arrays are valuable tools for investigating β-amyloid pathology from a functional perspective, helping to bridge the gap between cellular and network pathology and disease symptoms. The use of microelectrode arrays provides a functional insight into Alzheimer's disease pathology which will aid in the development of novel therapeutic interventions.
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Affiliation(s)
- Aoife O'connell
- Pharmacology and Therapeutics, School of Medicine, Galway Neuroscience Centre, University of Galway, Ireland
| | - Leo Quinlan
- Physiology, School of Medicine, Regenerative Medicine Institute, University of Galway, Ireland
| | - Andrea Kwakowsky
- Pharmacology and Therapeutics, School of Medicine, Galway Neuroscience Centre, University of Galway, Ireland.
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2
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Scaduto P, Marcatti M, Bhatt N, Kayed R, Taglialatela G. Calcineurin inhibition prevents synaptic plasticity deficit induced by brain-derived tau oligomers. Brain Commun 2024; 6:fcae277. [PMID: 39239152 PMCID: PMC11375858 DOI: 10.1093/braincomms/fcae277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2023] [Revised: 06/08/2024] [Accepted: 08/13/2024] [Indexed: 09/07/2024] Open
Abstract
Compelling evidence suggests that cognitive decline in Alzheimer's disease is associated with the accumulation and aggregation of tau protein, with the most toxic aggregates being in the form of oligomers. This underscores the necessity for direct isolation and analysis of brain-derived tau oligomers from patients with Alzheimer's disease, potentially offering novel perspectives into tau toxicity. Alzheimer's brain-derived tau oligomers are potent inhibitors of synaptic plasticity; however, the involved mechanism is still not fully understood. We previously reported a significantly reduced incidence of Alzheimer's disease in ageing humans chronically treated with a Food and Drug Administration-approved calcineurin inhibitor, FK506 (tacrolimus), used as an immunosuppressant after solid organ transplant. Using a combination of electrophysiological and RNA-sequencing techniques, we provide here evidence that FK506 has the potential to block the acute toxic effect of brain-derived tau oligomers on synaptic plasticity, as well as to restore the levels of some key synaptic mRNAs. These results further support FK506 as a promising novel therapeutic strategy for the treatment of Alzheimer's disease.
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Affiliation(s)
- Pietro Scaduto
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, TX 77555, USA
| | - Michela Marcatti
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, TX 77555, USA
| | - Nemil Bhatt
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, TX 77555, USA
| | - Rakez Kayed
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, TX 77555, USA
| | - Giulio Taglialatela
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch (UTMB), 301 University Blvd, Galveston, TX 77555, USA
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3
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Pascoal T, Rohden F, Ferreira P, Bellaver B, Ferrari-Souza JP, Aguzzoli C, Soares C, Abbas S, Zalzale H, Povala G, Lussier F, Leffa D, Bauer-Negrini G, Rahmouni N, Tissot C, Therriault JT, Servaes S, Stevenson J, Benedet A, Ashton N, Karikari T, Tudorascu D, Zetterberg H, Blennow K, Zimmer E, Souza D, Rosa-Neto P. Glial reactivity is linked to synaptic dysfunction across the aging and Alzheimer's disease spectrum. RESEARCH SQUARE 2024:rs.3.rs-4782732. [PMID: 39184102 PMCID: PMC11343173 DOI: 10.21203/rs.3.rs-4782732/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/27/2024]
Abstract
Previous studies have shown that glial and neuronal changes may trigger synaptic dysfunction in Alzheimer's disease(AD). However, the link between glial and neuronal markers and synaptic abnormalities in the living brain is poorly understood. Here, we investigated the association between biomarkers of astrocyte and microglial reactivity and synaptic dysfunction in 478 individuals across the aging and AD spectrum from two cohorts with available CSF measures of amyloid-β(Aβ), phosphorylated tau(pTau181), astrocyte reactivity(GFAP), microglial activation(sTREM2), and synaptic biomarkers(GAP43 and neurogranin). Elevated CSF GFAP levels were linked to presynaptic and postsynaptic dysfunction, regardless of cognitive status or Aβ presence. CSF sTREM2 levels were associated with presynaptic biomarkers in cognitively unimpaired and impaired Aβ + individuals and postsynaptic biomarkers in cognitively impaired Aβ + individuals. Notably, CSF pTau181 levels mediated all associations between GFAP or sTREM2 levels and synaptic dysfunction biomarkers. These results suggest that neuronal-related synaptic biomarkers could be used in clinical trials targeting glial reactivity in AD.
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4
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Baset A, Huang F. Shedding light on subiculum's role in human brain disorders. Brain Res Bull 2024; 214:110993. [PMID: 38825254 DOI: 10.1016/j.brainresbull.2024.110993] [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: 04/09/2024] [Revised: 05/17/2024] [Accepted: 05/30/2024] [Indexed: 06/04/2024]
Abstract
Subiculum is a pivotal output component of the hippocampal formation, a structure often overlooked in neuroscientific research. Here, this review aims to explore the role of the subiculum in various brain disorders, shedding light on its significance within the functional-neuroanatomical perspective on neurological diseases. The subiculum's involvement in multiple brain disorders was thoroughly examined. In Alzheimer's disease, subiculum alterations precede cognitive decline, while in epilepsy, the subiculum plays a critical role in seizure initiation. Stress involves the subiculum's impact on the hypothalamic-pituitary-adrenocortical axis. Moreover, the subiculum exhibits structural and functional changes in anxiety, schizophrenia, and Parkinson's disease, contributing to cognitive deficits. Bipolar disorder is linked to subiculum structural abnormalities, while autism spectrum disorder reveals an alteration of inward deformation in the subiculum. Lastly, frontotemporal dementia shows volumetric differences in the subiculum, emphasizing its contribution to the disorder's complexity. Taken together, this review consolidates existing knowledge on the subiculum's role in brain disorders, and may facilitate future research, diagnostic strategies, and therapeutic interventions for various neurological conditions.
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Affiliation(s)
- Abdul Baset
- Department of Neuroscience, City University of Hong Kong, Hong Kong Special Administrative Region of China; Centre for Regenerative Medicine and Health, Hong Kong Institute of Science & Innovation, Chinese Academy of Sciences, Hong Kong Special Administrative Region of China
| | - Fengwen Huang
- Department of Neuroscience, City University of Hong Kong, Hong Kong Special Administrative Region of China; Centre for Regenerative Medicine and Health, Hong Kong Institute of Science & Innovation, Chinese Academy of Sciences, Hong Kong Special Administrative Region of China.
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5
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Armijo-Weingart L, San Martin L, Gallegos S, Araya A, Konar-Nie M, Fernandez-Pérez E, Aguayo LG. Loss of glycine receptors in the nucleus accumbens and ethanol reward in an Alzheimer´s Disease mouse model. Prog Neurobiol 2024; 237:102616. [PMID: 38723884 PMCID: PMC11163974 DOI: 10.1016/j.pneurobio.2024.102616] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2023] [Revised: 03/21/2024] [Accepted: 05/01/2024] [Indexed: 05/12/2024]
Abstract
Alterations in cognitive and non-cognitive cerebral functions characterize Alzheimer's disease (AD). Cortical and hippocampal impairments related to extracellular accumulation of Aβ in AD animal models have been extensively investigated. However, recent reports have also implicated intracellular Aβ in limbic regions, such as the nucleus accumbens (nAc). Accumbal neurons express high levels of inhibitory glycine receptors (GlyRs) that are allosterically modulated by ethanol and have a role in controlling its intake. In the present study, we investigated how GlyRs in the 2xTg mice (AD model) affect nAc functions and ethanol intake behavior. Using transgenic and control aged-matched litter mates, we found that the GlyRα2 subunit was significantly decreased in AD mice (6-month-old). We also examined intracellular calcium dynamics using the fluorescent calcium protein reporter GCaMP in slice photometry. We also found that the calcium signal mediated by GlyRs, but not GABAAR, was also reduced in AD neurons. Additionally, ethanol potentiation was significantly decreased in accumbal neurons in the AD mice. Finally, we performed drinking in the dark (DID) experiments and found that 2xTg mice consumed less ethanol on the last day of DID, in agreement with a lower blood ethanol concentration. 2xTg mice also showed lower sucrose consumption, indicating that overall food reward was altered. In conclusion, the data support the role of GlyRs in nAc neuron excitability and a decreased glycinergic activity in the 2xTg mice that might lead to impairment in reward processing at an early stage of the disease.
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Affiliation(s)
- Lorena Armijo-Weingart
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile; Programa de Neurociencia, Psiquiatría y Salud Mental (NEPSAM), Universidad de Concepción, Chile
| | - Loreto San Martin
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile; Programa de Neurociencia, Psiquiatría y Salud Mental (NEPSAM), Universidad de Concepción, Chile
| | - Scarlet Gallegos
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile
| | - Anibal Araya
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile
| | - Macarena Konar-Nie
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile
| | - Eduardo Fernandez-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile; Programa de Neurociencia, Psiquiatría y Salud Mental (NEPSAM), Universidad de Concepción, Chile
| | - Luis G Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Universidad de Concepción, Chile.
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van Nifterick AM, Scheijbeler EP, Gouw AA, de Haan W, Stam CJ. Local signal variability and functional connectivity: Sensitive measures of the excitation-inhibition ratio? Cogn Neurodyn 2024; 18:519-537. [PMID: 38699618 PMCID: PMC11061092 DOI: 10.1007/s11571-023-10003-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 06/08/2023] [Accepted: 08/13/2023] [Indexed: 05/05/2024] Open
Abstract
A novel network version of permutation entropy, the inverted joint permutation entropy (JPEinv), holds potential as non-invasive biomarker of abnormal excitation-inhibition (E-I) ratio in Alzheimer's disease (AD). In this computational modelling study, we test the hypotheses that this metric, and related measures of signal variability and functional connectivity, are sensitive to altered E-I ratios. The E-I ratio in each neural mass of a whole-brain computational network model was systematically varied. We evaluated whether JPEinv, local signal variability (by permutation entropy) and functional connectivity (by weighted symbolic mutual information (wsMI)) were related to E-I ratio, on whole-brain and regional level. The hub disruption index can identify regions primarily affected in terms of functional connectivity strength (or: degree) by the altered E-I ratios. Analyses were performed for a range of coupling strengths, filter and time-delay settings. On whole-brain level, higher E-I ratios were associated with higher functional connectivity (by JPEinv and wsMI) and lower local signal variability. These relationships were nonlinear and depended on the coupling strength, filter and time-delay settings. On regional level, hub-like regions showed a selective decrease in functional degree (by JPEinv and wsMI) upon a lower E-I ratio, and non-hub-like regions showed a selective increase in degree upon a higher E-I ratio. These results suggest that abnormal functional connectivity and signal variability, as previously reported in patients across the AD continuum, can inform us about altered E-I ratios. Supplementary Information The online version contains supplementary material available at 10.1007/s11571-023-10003-x.
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Affiliation(s)
- Anne M. van Nifterick
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Elliz P. Scheijbeler
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Alida A. Gouw
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Willem de Haan
- Alzheimer Center Amsterdam, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
| | - Cornelis J. Stam
- Clinical Neurophysiology and MEG Center, Neurology, Vrije Universiteit Amsterdam, Amsterdam UMC Location VUmc, Amsterdam, The Netherlands
- Amsterdam Neuroscience, Neurodegeneration, Amsterdam, The Netherlands
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7
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da Silva SP, de Castro CCM, Rabelo LN, Engelberth RC, Fernández-Calvo B, Fiuza FP. Neuropathological and sociodemographic factors associated with the cortical amyloid load in aging and Alzheimer's disease. GeroScience 2024; 46:621-643. [PMID: 37870702 PMCID: PMC10828279 DOI: 10.1007/s11357-023-00982-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Accepted: 10/10/2023] [Indexed: 10/24/2023] Open
Abstract
Alzheimer's disease (AD) is the leading cause of dementia and is characterized by a progressive decline in cognitive abilities. A pathological hallmark of AD is a region-specific accumulation of the amyloid-beta protein (Aβ). Here, we explored the association between regional Aβ deposition, sociodemographic, and local biochemical factors. We quantified the Aβ burden in postmortem cortical samples from parietal (PCx) and temporal (TCx) regions of 27 cognitively unimpaired (CU) and 15 AD donors, aged 78-100 + years. Histological images of Aβ immunohistochemistry and local concentrations of pathological and inflammatory proteins were obtained at the "Aging, Dementia and TBI Study" open database. We used the area fraction fractionator stereological methodology to quantify the Aβ burden in the gray and white matter within each cortical region. We found higher Aβ burdens in the TCx of AD octogenarians compared to CU ones. We also found higher Aβ loads in the PCx of AD nonagenarians than in AD octogenarians. Moreover, AD women exhibited increased Aβ deposition compared to CU women. Interestingly, we observed a negative correlation between education years and Aβ burden in the white matter of both cortices in CU samples. In AD brains, the Aβ40, Aβ42, and pTau181 isoforms of Aβ and Tau proteins were positively correlated with the Aβ burden. Additionally, in the TCx of AD donors, the proinflammatory cytokine TNFα showed a positive correlation with the Aβ load. These novel findings contribute to understanding the interplay between sociodemographic characteristics, local inflammatory signaling, and the development of AD-related pathology in the cerebral cortex.
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Affiliation(s)
- Sayonara P da Silva
- Graduate Program in Neuroengineering, Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Macaíba, RN, 59280-000, Brazil
| | - Carla C M de Castro
- Graduate Program in Neuroengineering, Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Macaíba, RN, 59280-000, Brazil
| | - Lívia N Rabelo
- Graduate Program in Neuroengineering, Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Macaíba, RN, 59280-000, Brazil
- Laboratory of Neurochemical Studies, Department of Physiology and Behavior, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, Brazil
| | - Rovena C Engelberth
- Laboratory of Neurochemical Studies, Department of Physiology and Behavior, Biosciences Center, Federal University of Rio Grande Do Norte, Natal, Brazil
| | - Bernardino Fernández-Calvo
- Department of Psychology, University of Córdoba, Córdoba, Spain
- Maimonides Biomedical Research Institute of Córdoba (IMIBIC), Córdoba, Spain
- Reina Sofia University Hospital, Córdoba, Spain
- Department of Psychology, Federal University of Paraíba, João Pessoa, Brazil
| | - Felipe P Fiuza
- Graduate Program in Neuroengineering, Edmond and Lily Safra International Institute of Neuroscience, Santos Dumont Institute, Macaíba, RN, 59280-000, Brazil.
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Niraula S, Yan SS, Subramanian J. Amyloid Pathology Impairs Experience-Dependent Inhibitory Synaptic Plasticity. J Neurosci 2024; 44:e0702232023. [PMID: 38050105 PMCID: PMC10860629 DOI: 10.1523/jneurosci.0702-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Revised: 11/09/2023] [Accepted: 11/14/2023] [Indexed: 12/06/2023] Open
Abstract
Alzheimer's disease patients and mouse models exhibit aberrant neuronal activity and altered excitatory-to-inhibitory synaptic ratio. Using multicolor two-photon microscopy, we test how amyloid pathology alters the structural dynamics of excitatory and inhibitory synapses and their adaptation to altered visual experience in vivo in the visual cortex. We show that the baseline dynamics of mature excitatory synapses and their adaptation to visual deprivation are not altered in amyloidosis. Likewise, the baseline dynamics of inhibitory synapses are not affected. In contrast, visual deprivation fails to induce inhibitory synapse loss in amyloidosis, a phenomenon observed in nonpathological conditions. Intriguingly, inhibitory synapse loss associated with visual deprivation in nonpathological mice is accompanied by subtle broadening of spontaneous but not visually evoked calcium transients. However, such broadening does not manifest in the context of amyloidosis. We also show that excitatory and inhibitory synapse loss is locally clustered under the nonpathological state. In contrast, a fraction of synapse loss is not locally clustered in amyloidosis, indicating an impairment in inhibitory synapse adaptation to changes in excitatory synaptic activity.
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Affiliation(s)
- Suraj Niraula
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
| | - Shirley ShiDu Yan
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
- Department of Surgery, Vagelos College of Physicians and Surgeons of Columbia University, New York, New York 10032
| | - Jaichandar Subramanian
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, Kansas 66045
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Zhang L, Yao Q, Hu J, Qiu B, Xiao Y, Zhang Q, Zeng Y, Zheng S, Zhang Y, Wan Y, Zheng X, Zeng Q. Hotspots and trends of microglia in Alzheimer's disease: a bibliometric analysis during 2000-2022. Eur J Med Res 2024; 29:75. [PMID: 38268044 PMCID: PMC10807212 DOI: 10.1186/s40001-023-01602-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 12/17/2023] [Indexed: 01/26/2024] Open
Abstract
BACKGROUND Alzheimer's disease is one common type of dementia. Numerous studies have suggested a correlation between Alzheimer's disease and inflammation. Microglia mainly participate in the inflammatory response in the brain. Currently, ample evidence has shown that microglia are closely related to the occurrence and development of Alzheimer's disease. OBJECTIVE We opted for bibliometric analysis to comprehensively summarize the advancements in the study of microglia in Alzheimer's disease, aiming to provide researchers with current trends and future research directions. METHODS All articles and reviews pertaining to microglia in Alzheimer's disease from 2000 to 2022 were downloaded through Web of Science Core Collection. The results were subjected to bibliometric analysis using VOSviewer 1.6.18 and CiteSpace 6.1 R2. RESULTS Overall, 7449 publications were included. The number of publications was increasing yearly. The United States has published the most publications. Harvard Medical School has published the most papers of all institutions. Journal of Alzheimer's Disease and Journal of Neuroscience were the journals with the most studies and the most commonly cited, respectively. Mt Heneka is the author with the highest productivity and co-citation. After analysis, the most common keywords are neuroinflammation, amyloid-beta, inflammation, neurodegeneration. Gut microbiota, extracellular vesicle, dysfunction and meta-analysis are the hotspots of research at the present stage and are likely to continue. CONCLUSION NLRP3 inflammasome, TREM2, gut microbiota, mitochondrial dysfunction, exosomes are research hotspots. The relationship between microglia-mediated neuroinflammation and Alzheimer's disease have been the focus of current research and the development trend of future research.
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Affiliation(s)
- Lijie Zhang
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China
| | - Qiuru Yao
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- School of Nursing, Southern Medical University, Guangzhou, China
| | - Jinjing Hu
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China
| | - Baizhi Qiu
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- School of Nursing, Southern Medical University, Guangzhou, China
| | - Yupeng Xiao
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China
| | - Qi Zhang
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China
| | - Yuting Zeng
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
| | - Shuqi Zheng
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China
| | - Youao Zhang
- The First School of Clinical Medicine, Southern Medical University, Guangzhou, China
| | - Yantong Wan
- College of Anesthesiology, Southern Medical University, Guangzhou, China.
| | - Xiaoyan Zheng
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China.
| | - Qing Zeng
- Department of Rehabilitation Medicine, Zhujiang Hospital, Southern Medical University, Guangzhou, China.
- School of Rehabilitation Sciences, Southern Medical University, Guangzhou, China.
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10
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Scheinman SB, Tseng KY, Alford S, Tai LM. Higher Neuronal Facilitation and Potentiation with APOE4 Suppressed by Angiotensin II. Mol Neurobiol 2024; 61:120-131. [PMID: 37589833 PMCID: PMC10843153 DOI: 10.1007/s12035-023-03556-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 08/01/2023] [Indexed: 08/18/2023]
Abstract
Progressive hippocampal degeneration is a key component of Alzheimer's disease (AD) progression. Therefore, identifying how hippocampal neuronal function is modulated early in AD is an important approach to eventually prevent degeneration. AD-risk factors and signaling molecules likely modulate neuronal function, including APOE genotype and angiotensin II. Compared to APOE3, APOE4 increases AD risk up to 12-fold, and high levels of angiotensin II are hypothesized to disrupt neuronal function in AD. However, the extent that APOE and angiotensin II modulates the hippocampal neuronal phenotype in AD-relevant models is unknown. To address this issue, we used electrophysiological techniques to assess the impact of APOE genotype and angiotensin II on basal synaptic transmission, presynaptic, and post-synaptic activity in mice that express human APOE3 (E3FAD) or APOE4 (E4FAD) and overproduce Aβ. We found that compared to E3FAD mice, E4FAD mice have lower synaptic activity, but higher levels of paired-pulse facilitation (PPF) and long-term potentiation (LTP) in the Schaffer Collateral Commissural Pathway (SCCP) of the hippocampus. We also found that exogenous angiotensin II has a profound inhibitory effect on hippocampal LTP in both E3FAD and E4FAD mice. Collectively, our data suggests that APOE4 and Aβ are associated with a hippocampal phenotype comprised of lower basal activity and higher responses to high-frequency stimulation, the latter of which is suppressed by angiotensin II. These novel data suggest a potential mechanistic link between hippocampal activity, APOE4 genotype, and angiotensin II in AD.
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Affiliation(s)
- Sarah B Scheinman
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St. Rm 578 MC 512, Chicago, IL, 60612, USA
| | - Kuei Y Tseng
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St. Rm 578 MC 512, Chicago, IL, 60612, USA
| | - Simon Alford
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St. Rm 578 MC 512, Chicago, IL, 60612, USA
| | - Leon M Tai
- Department of Anatomy and Cell Biology, University of Illinois at Chicago, 808 S. Wood St. Rm 578 MC 512, Chicago, IL, 60612, USA.
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Niraula S, Yan SS, Subramanian J. Amyloid pathology impairs experience-dependent inhibitory synaptic plasticity. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.04.539450. [PMID: 37205469 PMCID: PMC10187277 DOI: 10.1101/2023.05.04.539450] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Alzheimer's disease patients and mouse models exhibit aberrant neuronal activity and altered excitatory-to-inhibitory synaptic ratio. Using multicolor two-photon microscopy, we test how amyloid pathology alters the structural dynamics of excitatory and inhibitory synapses and their adaptation to altered visual experience in vivo in the visual cortex. We show that the baseline dynamics of mature excitatory synapses and their adaptation to visual deprivation are not altered in amyloidosis. Likewise, the baseline dynamics of inhibitory synapses are not affected. In contrast, visual deprivation fails to induce inhibitory synapse loss in amyloidosis, a phenomenon observed in nonpathological conditions. Intriguingly, inhibitory synapse loss associated with visual deprivation in nonpathological mice is accompanied by the broadening of spontaneous but not visually evoked calcium transients. However, such broadening does not manifest in the context of amyloidosis. We also show that excitatory and inhibitory synapse loss is locally clustered under the nonpathological state. In contrast, a fraction of synapse loss is not locally clustered in amyloidosis, indicating an impairment in inhibitory synapse adaptation to changes in excitatory synaptic activity.
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Affiliation(s)
- Suraj Niraula
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
| | - Shirley ShiDu Yan
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
- Department of Surgery, Vagelos College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Jaichandar Subramanian
- Department of Pharmacology and Toxicology, School of Pharmacy, University of Kansas, Lawrence, KS 66045, USA
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Guo G, Fan L, Yan Y, Xu Y, Deng Z, Tian M, Geng Y, Xia Z, Xu Y. Shared metabolic shifts in endothelial cells in stroke and Alzheimer's disease revealed by integrated analysis. Sci Data 2023; 10:666. [PMID: 37775708 PMCID: PMC10542331 DOI: 10.1038/s41597-023-02512-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2023] [Accepted: 08/30/2023] [Indexed: 10/01/2023] Open
Abstract
Since metabolic dysregulation is a hallmark of both stroke and Alzheimer's disease (AD), mining shared metabolic patterns in these diseases will help to identify their possible pathogenic mechanisms and potential intervention targets. However, a systematic integration analysis of the metabolic networks of the these diseases is still lacking. In this study, we integrated single-cell RNA sequencing datasets of ischemic stroke (IS), hemorrhagic stroke (HS) and AD models to construct metabolic flux profiles at the single-cell level. We discovered that the three disorders cause shared metabolic shifts in endothelial cells. These altered metabolic modules were mainly enriched in the transporter-related pathways and were predicted to potentially lead to a decrease in metabolites such as pyruvate and fumarate. We further found that Lef1, Elk3 and Fosl1 may be upstream transcriptional regulators causing metabolic shifts and may be possible targets for interventions that halt the course of neurodegeneration.
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Affiliation(s)
- Guangyu Guo
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- NHC Key Laboratory of Prevention and treatment of Cerebrovascular Diseases, Zhengzhou, China
- Clinical Systems Biology Laboratories, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Liyuan Fan
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Yingxue Yan
- Clinical Systems Biology Laboratories, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Yunhao Xu
- Clinical Systems Biology Laboratories, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Academy of Medical Sciences of Zhengzhou University, Zhengzhou, China
| | - Zhifen Deng
- Clinical Systems Biology Laboratories, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Miaomiao Tian
- Clinical Systems Biology Laboratories, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Yaoqi Geng
- Clinical Systems Biology Laboratories, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
- Department of Endocrinology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, China
| | - Zongping Xia
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
- NHC Key Laboratory of Prevention and treatment of Cerebrovascular Diseases, Zhengzhou, China.
- Clinical Systems Biology Laboratories, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, China.
| | - Yuming Xu
- Department of Neurology, The First Affiliated Hospital of Zhengzhou University, Zhengzhou, Henan, China.
- NHC Key Laboratory of Prevention and treatment of Cerebrovascular Diseases, Zhengzhou, China.
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13
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Hernández-Frausto M, Bilash OM, Masurkar AV, Basu J. Local and long-range GABAergic circuits in hippocampal area CA1 and their link to Alzheimer's disease. Front Neural Circuits 2023; 17:1223891. [PMID: 37841892 PMCID: PMC10570439 DOI: 10.3389/fncir.2023.1223891] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Accepted: 09/08/2023] [Indexed: 10/17/2023] Open
Abstract
GABAergic inhibitory neurons are the principal source of inhibition in the brain. Traditionally, their role in maintaining the balance of excitation-inhibition has been emphasized. Beyond homeostatic functions, recent circuit mapping and functional manipulation studies have revealed a wide range of specific roles that GABAergic circuits play in dynamically tilting excitation-inhibition coupling across spatio-temporal scales. These span from gating of compartment- and input-specific signaling, gain modulation, shaping input-output functions and synaptic plasticity, to generating signal-to-noise contrast, defining temporal windows for integration and rate codes, as well as organizing neural assemblies, and coordinating inter-regional synchrony. GABAergic circuits are thus instrumental in controlling single-neuron computations and behaviorally-linked network activity. The activity dependent modulation of sensory and mnemonic information processing by GABAergic circuits is pivotal for the formation and maintenance of episodic memories in the hippocampus. Here, we present an overview of the local and long-range GABAergic circuits that modulate the dynamics of excitation-inhibition and disinhibition in the main output area of the hippocampus CA1, which is crucial for episodic memory. Specifically, we link recent findings pertaining to GABAergic neuron molecular markers, electrophysiological properties, and synaptic wiring with their function at the circuit level. Lastly, given that area CA1 is particularly impaired during early stages of Alzheimer's disease, we emphasize how these GABAergic circuits may contribute to and be involved in the pathophysiology.
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Affiliation(s)
- Melissa Hernández-Frausto
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, United States
| | - Olesia M. Bilash
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, United States
| | - Arjun V. Masurkar
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, United States
- Center for Cognitive Neurology, Department of Neurology, New York University Grossman School of Medicine, New York, NY, United States
| | - Jayeeta Basu
- Neuroscience Institute, New York University Langone Health, New York, NY, United States
- Department of Neuroscience and Physiology, New York University Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, New York University Grossman School of Medicine, New York, NY, United States
- Center for Neural Science, New York University, New York, NY, United States
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14
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Gazestani V, Kamath T, Nadaf NM, Dougalis A, Burris SJ, Rooney B, Junkkari A, Vanderburg C, Pelkonen A, Gomez-Budia M, Välimäki NN, Rauramaa T, Therrien M, Koivisto AM, Tegtmeyer M, Herukka SK, Abdulraouf A, Marsh SE, Hiltunen M, Nehme R, Malm T, Stevens B, Leinonen V, Macosko EZ. Early Alzheimer's disease pathology in human cortex involves transient cell states. Cell 2023; 186:4438-4453.e23. [PMID: 37774681 PMCID: PMC11107481 DOI: 10.1016/j.cell.2023.08.005] [Citation(s) in RCA: 43] [Impact Index Per Article: 43.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/31/2023] [Accepted: 08/03/2023] [Indexed: 10/01/2023]
Abstract
Cellular perturbations underlying Alzheimer's disease (AD) are primarily studied in human postmortem samples and model organisms. Here, we generated a single-nucleus atlas from a rare cohort of cortical biopsies from living individuals with varying degrees of AD pathology. We next performed a systematic cross-disease and cross-species integrative analysis to identify a set of cell states that are specific to early AD pathology. These changes-which we refer to as the early cortical amyloid response-were prominent in neurons, wherein we identified a transitional hyperactive state preceding the loss of excitatory neurons, which we confirmed by acute slice physiology on independent biopsy specimens. Microglia overexpressing neuroinflammatory-related processes also expanded as AD pathology increased. Finally, both oligodendrocytes and pyramidal neurons upregulated genes associated with β-amyloid production and processing during this early hyperactive phase. Our integrative analysis provides an organizing framework for targeting circuit dysfunction, neuroinflammation, and amyloid production early in AD pathogenesis.
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Affiliation(s)
- Vahid Gazestani
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Tushar Kamath
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Harvard Graduate Program in Biophysics and Harvard/MIT MD-PhD Program, Harvard University, Cambridge, MA 02139, USA
| | - Naeem M Nadaf
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Antonios Dougalis
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - S J Burris
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Brendan Rooney
- Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Antti Junkkari
- Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland
| | | | - Anssi Pelkonen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mireia Gomez-Budia
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Nelli-Noora Välimäki
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Tuomas Rauramaa
- Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; Department of Pathology, Kuopio University Hospital, Kuopio, Finland
| | | | - Anne M Koivisto
- Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA; Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; Department of Neurology, Kuopio University Hospital, Kuopio, Finland; Department of Neurosciences, University of Helsinki, Helsinki, Finland; Department of Geriatrics, Helsinki University Hospital, Helsinki, Finland
| | | | - Sanna-Kaisa Herukka
- Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; Department of Neurology, Kuopio University Hospital, Kuopio, Finland
| | | | - Samuel E Marsh
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA
| | - Mikko Hiltunen
- Institute of Biomedicine, University of Eastern Finland, Kuopio, Finland
| | - Ralda Nehme
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Beth Stevens
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA; Howard Hughes Medical Institute (HHMI), Boston, MA 02115, USA
| | - Ville Leinonen
- Institute of Clinical Medicine, University of Eastern Finland, Kuopio, Finland; Department of Neurosurgery, Kuopio University Hospital, Kuopio, Finland
| | - Evan Z Macosko
- Broad Institute of MIT and Harvard, Cambridge, MA 02142, USA; Massachusetts General Hospital, Department of Psychiatry, Boston, MA 02114, USA.
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15
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Scheinman SB, Tseng KY, Alford S, Tai LM. Higher Neuronal Facilitation and Potentiation with APOE4 Suppressed by Angiotensin II. RESEARCH SQUARE 2023:rs.3.rs-2960437. [PMID: 37292788 PMCID: PMC10246245 DOI: 10.21203/rs.3.rs-2960437/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Progressive hippocampal degeneration is a key component of Alzheimer's disease (AD) progression. Therefore, identifying how hippocampal neuronal function is modulated early in AD is an important approach to eventually prevent degeneration. AD-risk factors and signaling molecules likely modulate neuronal function, including APOE genotype and angiotensin II. Compared to APOE3 , APOE4 increases AD risk up to 12-fold, and high levels of angiotensin II are hypothesized to disrupt neuronal function in AD. However, the extent that APOE and angiotensin II modulates the hippocampal neuronal phenotype in AD-relevant models is unknown. To address this issue, we used electrophysiological techniques to assess the impact of APOE genotype and angiotensin II on basal synaptic transmission, presynaptic and post-synaptic activity in mice that express human APOE3 (E3FAD) or APOE4 (E4FAD) and overproduce Aβ. We found that compared to E3FAD mice, E4FAD mice had lower basal synaptic activity, but higher levels of paired pulse facilitation (PPF) and Long-Term Potentiation (LTP) in the Schaffer Collateral Commissural Pathway (SCCP) of the hippocampus. We also found that exogenous angiotensin II has a profound inhibitory effect on hippocampal LTP in both E3FAD and E4FAD mice. Collectively, our data suggests that APOE4 and Aβ are associated with a hippocampal phenotype comprised of lower basal activity and higher responses to high frequency stimulation, the latter of which is suppressed by angiotensin II. These novel data suggest a potential mechanistic link between hippocampal activity, APOE4 genotype and angiotensin II in AD.
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Affiliation(s)
| | - Kuei Y Tseng
- University of Illinois at Chicago College of Medicine
| | - Simon Alford
- University of Illinois at Chicago College of Medicine
| | - Leon M Tai
- University of Illinois at Chicago College of Medicine
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16
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Hirota Y, Sakakibara Y, Takei K, Nishijima R, Sekiya M, Iijima KM. Alzheimer's Disease-Related Phospho-Tau181 Signals Are Localized to Demyelinated Axons of Parvalbumin-Positive GABAergic Interneurons in an App Knock-In Mouse Model of Amyloid-β Pathology. J Alzheimers Dis 2023:JAD230121. [PMID: 37212118 DOI: 10.3233/jad-230121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
BACKGROUND The tau protein phosphorylated at Thr181 (p-tau181) in cerebrospinal fluid and blood is a sensitive biomarker for Alzheimer's disease (AD). Increased p-tau181 levels correlate well with amyloid-β (Aβ) pathology and precede neurofibrillary tangle formation in the early stage of AD; however, the relationship between p-tau181 and Aβ-mediated pathology is less well understood. We recently reported that p-tau181 represents axonal abnormalities in mice with Aβ pathology (AppNLGF). However, from which neuronal subtype(s) these p-tau181-positive axons originate remains elusive. OBJECTIVE The main purpose of this study is to differentiate neuronal subtype(s) and elucidate damage associated with p-tau181-positive axons by immunohistochemical analysis of AppNLGF mice brains. METHODS Colocalization between p-tau181 and (1) unmyelinated axons positive for vesicular acetylcholine transporter or norepinephrine transporter and (2) myelinated axons positive for vesicular glutamate transporter, vesicular GABA transporter, or parvalbumin in the brains of 24-month-old AppNLGF and control mice without Aβ pathology were analyzed. The density of these axons was also compared. RESULTS Unmyelinated axons of cholinergic or noradrenergic neurons did not overlap with p-tau181. By contrast, p-tau181 signals colocalized with myelinated axons of parvalbumin-positive GABAergic interneurons but not of glutamatergic neurons. Interestingly, the density of unmyelinated axons was significantly decreased in AppNLGF mice, whereas that of glutamatergic, GABAergic, or p-tau181-positive axons was less affected. Instead, myelin sheaths surrounding p-tau181-positive axons were significantly reduced in AppNLGF mice. CONCLUSION This study demonstrates that p-tau181 signals colocalize with axons of parvalbumin-positive GABAergic interneurons with disrupted myelin sheaths in the brains of a mouse model of Aβ pathology.
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Affiliation(s)
- Yu Hirota
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
- Japan Society for the Promotion of Science, Chiyoda-ku, Tokyo, Japan
| | - Yasufumi Sakakibara
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Kimi Takei
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Risa Nishijima
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
| | - Michiko Sekiya
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
- Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
| | - Koichi M Iijima
- Department of Neurogenetics, Center for Development of Advanced Medicine for Dementia, National Center for Geriatrics and Gerontology, Obu, Aichi, Japan
- Department of Experimental Gerontology, Graduate School of Pharmaceutical Sciences, Nagoya City University, Nagoya, Japan
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17
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Meftah S, Gan J. Alzheimer's disease as a synaptopathy: Evidence for dysfunction of synapses during disease progression. Front Synaptic Neurosci 2023; 15:1129036. [PMID: 36970154 PMCID: PMC10033629 DOI: 10.3389/fnsyn.2023.1129036] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Accepted: 02/23/2023] [Indexed: 03/11/2023] Open
Abstract
The synapse has consistently been considered a vulnerable and critical target within Alzheimer's disease, and synapse loss is, to date, one of the main biological correlates of cognitive decline within Alzheimer's disease. This occurs prior to neuronal loss with ample evidence that synaptic dysfunction precedes this, in support of the idea that synaptic failure is a crucial stage within disease pathogenesis. The two main pathological hallmarks of Alzheimer's disease, abnormal aggregates of amyloid or tau proteins, have had demonstrable effects on synaptic physiology in animal and cellular models of Alzheimer's disease. There is also growing evidence that these two proteins may have a synergistic effect on neurophysiological dysfunction. Here, we review some of the main findings of synaptic alterations in Alzheimer's disease, and what we know from Alzheimer's disease animal and cellular models. First, we briefly summarize some of the human evidence to suggest that synapses are altered, including how this relates to network activity. Subsequently, animal and cellular models of Alzheimer's disease are considered, highlighting mouse models of amyloid and tau pathology and the role these proteins may play in synaptic dysfunction, either in isolation or examining how the two pathologies may interact in dysfunction. This specifically focuses on neurophysiological function and dysfunction observed within these animal models, typically measured using electrophysiology or calcium imaging. Following synaptic dysfunction and loss, it would be impossible to imagine that this would not alter oscillatory activity within the brain. Therefore, this review also discusses how this may underpin some of the aberrant oscillatory patterns seen in animal models of Alzheimer's disease and human patients. Finally, an overview of some key directions and considerations in the field of synaptic dysfunction in Alzheimer's disease is covered. This includes current therapeutics that are targeted specifically at synaptic dysfunction, but also methods that modulate activity to rescue aberrant oscillatory patterns. Other important future avenues of note in this field include the role of non-neuronal cell types such as astrocytes and microglia, and mechanisms of dysfunction independent of amyloid and tau in Alzheimer's disease. The synapse will certainly continue to be an important target within Alzheimer's disease for the foreseeable future.
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Affiliation(s)
- Soraya Meftah
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | - Jian Gan
- UK Dementia Research Institute, The University of Edinburgh, Edinburgh, United Kingdom
- Centre for Discovery Brain Sciences, The University of Edinburgh, Edinburgh, United Kingdom
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