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Sano M, Iwatsuki K, Hirata H, Hoshiyama M. Imbalance in positive and negative acceleration ratio of alpha oscillation in patients with complex regional pain syndrome. Heliyon 2024; 10:e36463. [PMID: 39281607 PMCID: PMC11401108 DOI: 10.1016/j.heliyon.2024.e36463] [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: 02/12/2024] [Revised: 08/14/2024] [Accepted: 08/15/2024] [Indexed: 09/18/2024] Open
Abstract
Objectives To elucidate the functional characteristics of the brain in the presence of chronic pain using electroencephalography (EEG), with a focus on the dynamics of neural excitation and inhibition. Methods Resting-state EEG was performed in: 17 patients with complex regional pain syndrome (CRPS) who exhibited chronic pain higher than 20 on the visual analogue scale (VAS), 6 patients with reduced CRPS symptoms and chronic pain less than 20 on VAS, and healthy age-matched controls. For the analysis, 50 s of electroencephalogram (EEG) signals were extracted from EEG recordings during wakefulness and rest with eyes closed. The envelope of the alpha frequency band was calculated by examining the positive and negative accelerations of the envelope oscillation, ratio of positive (Ap) to negative (An) accelerations (Ap-An ratio), and mean amplitude of the envelope. Comparisons were made between patients and controls, and correlations between these EEG measures and the subjective pain VAS were evaluated.Significant differences in the value of Ap, An and Ap-An ratio were observed at temporal and central electrodes between patients with pain symptoms and controls. Those with reduced CRPS symptoms exhibited a distinct Ap-An ratio at the majority of electrodes when compared with those exhibiting chronic pain. Conclusions Distinct patterns in alpha wave envelope dynamics, reflecting excitatory and inhibitory activities, were associated with chronic pain in patients with CRPS. The pain-relieved state of CRPS suggested that a new balance of activities was established. This relationship indicated a potential association between altered alpha oscillation characteristics and the subjective experience of pain. Significance This study introduces a novel method for analyzing alpha oscillation envelopes, providing new insights into the neural pathophysiology of chronic pain in CRPS patients. This approach has the potential to enhance our understanding of the alterations in brain function that occur under chronic pain conditions.
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Affiliation(s)
- Misako Sano
- Division of Prevention & Rehabilitation Sciences, Graduate School of Health Sciences, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-8673, Japan
| | - Katsuyuki Iwatsuki
- Department of Hnad Surgery, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, 466-8550, Japan
| | - Hitoshi Hirata
- Department of Hnad Surgery, Graduate School of Medicine, Nagoya University, 65 Tsurumai-cho, Showa-ku, 466-8550, Japan
| | - Minoru Hoshiyama
- Division of Prevention & Rehabilitation Sciences, Graduate School of Health Sciences, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-8673, Japan
- Brain & Mind Research Center, Nagoya University, 1-1-20 Daiko-Minami, Higashi-ku, Nagoya, 461-8673, Japan
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2
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Rivera J, Sharma B, Torres MM, Kumar S. Factors affecting the GABAergic synapse function in Alzheimer's disease: Focus on microRNAs. Ageing Res Rev 2023; 92:102123. [PMID: 37967653 DOI: 10.1016/j.arr.2023.102123] [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: 09/01/2023] [Revised: 11/07/2023] [Accepted: 11/09/2023] [Indexed: 11/17/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurological disease characterized by the loss of cognitive function, confusion, and memory deficit. Accumulation of abnormal proteins, amyloid beta (Aß), and phosphorylated Tau (p-tau) forms plaques and tangles that deteriorate synapse function, resulting in neurodegeneration and cognitive decline in AD. The human brain is composed of different types of neurons and/or synapses that are functionally defective in AD. The GABAergic synapse, the most abundant inhibitory neuron in the human brain was found to be dysfunctional in AD and contributes to disrupting neurological function. This study explored the types of GABA receptors associated with neurological dysfunction and various biological and environmental factors that cause GABAergic neuron dysfunction in AD, such as Aβ, p-tau, aging, sex, astrocytes, microglia, APOE, mental disorder, diet, physical activity, and sleep. Furthermore, we explored the role of microRNAs (miRNAs) in the regulation of GABAergic synapse function in neurological disorders and AD states. We also discuss the molecular mechanisms underlying GABAergic synapse dysfunction with a focus on miR-27b, miR-30a, miR-190a/b, miR-33, miR-51, miR-129-5p, miR-376-3p, miR-376c, miR-30b and miR-502-3p. The purpose of our article is to highlight the recent research on miRNAs affecting the regulation of GABAergic synapse function and factors that contribute to the progression of AD.
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Affiliation(s)
- Jazmin Rivera
- Center of Emphasis in Neuroscience, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA
| | - Bhupender Sharma
- Center of Emphasis in Neuroscience, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA
| | - Melissa M Torres
- Center of Emphasis in Neuroscience, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA
| | - Subodh Kumar
- Center of Emphasis in Neuroscience, Department of Molecular and Translational Medicine, Paul L. Foster School of Medicine, Texas Tech University Health Sciences Center, El Paso, TX, USA; L. Frederick Francis Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, El Paso, TX, USA.
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Mao R, Xu S, Sun G, Yu Y, Zuo Z, Wang Y, Yang K, Zhang Z, Yang W. Triptolide injection reduces Alzheimer's disease-like pathology in mice. Synapse 2023; 77:e22261. [PMID: 36633502 DOI: 10.1002/syn.22261] [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: 03/24/2022] [Revised: 12/21/2022] [Accepted: 01/08/2023] [Indexed: 01/13/2023]
Abstract
Triptolide is an epoxidized diterpene lactone isolated from Tripterygium wilfordii. Studies have shown that triptolide exerts organ-protective effects. However, it remains unknown whether triptolide improves Alzheimer's disease (AD)-like presentations. Thirty healthy 8-week-old male C57BL/6J mice were randomly divided into control (n = 10), model (n = 10), and triptolide (n = 10) groups. Amyloid-β (Aβ)42 was injected bilaterally into the ventricles of mice in the model group. Triptolide was injected intraperitoneally daily after injecting Aβ42 (a total of 30 days) in the triptolide group. Learning and memory were tested using the Morris water maze test. The deposition of Aβ42 in the hippocampus was detected using immunohistochemical staining. In the hippocampus, three synaptic-associated proteins-gephyrin, collybistin, and GABRA1 -were detected by western blotting. Furthermore, we used ELISA to detect proinflammatory cytokines, including TNF-α and IL-1β, in the blood and hippocampus. Moreover, superoxide dismutase (SOD), malondialdehyde (MDA), and GSH levels were measured using the corresponding kits. We found that triptolide improved spatial learning and memory in AD-like mice. Additionally, triptolide maintained the expression of gephyrin, collybistin, and GABRA1 and reduced Aβ in these mice. Additionally, triptolide reduced the expression of inflammatory cytokines and decreased oxidative damage in AD-like mice. Our study suggests that triptolide attenuates AD-like changes in the mouse brain.
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Affiliation(s)
- Rui Mao
- Department of Neurology, Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Shihao Xu
- Department of Neurology, Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Guangwen Sun
- Department of Neurology, Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei, China
- Department of Neurology, Sinopharm Dongfeng General Hospital, Jinzhou Medical University Union Training Base, Jinzhou, China
| | - Yingying Yu
- Department of Neurology, Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei, China
- Department of Neurology, Sinopharm Dongfeng General Hospital, Jinzhou Medical University Union Training Base, Jinzhou, China
| | - Zhiyi Zuo
- Department of Anesthesiology, University of Virginia School of Medicine, Charlottesville, Virginia
| | - Yuanyuan Wang
- Department of Neurology, Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Kun Yang
- Department of Anesthesiology, Sinopharm Dongfeng General Hospital, Jinzhou Medical University Union Training Base, Jinzhou, China
| | - Zhen Zhang
- Department of Orthopedics, Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei, China
| | - Wenqiong Yang
- Department of Neurology, Sinopharm Dongfeng General Hospital, Hubei University of Medicine, Shiyan, Hubei, China
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Chan P, Waxman RE, Woo S, Docherty C, Rayani K, Fischler I, Ghaffar O, Elmi S. Electroconvulsive Therapy for Neuropsychiatric Symptoms due to Major Neurocognitive Disorder: A Prospective, Observational Study. J ECT 2022; 38:81-87. [PMID: 35613007 DOI: 10.1097/yct.0000000000000814] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Neuropsychiatric symptoms (NPSs) in those with major neurocognitive disorder (MNCD) include the responsive behaviors of agitation and aggression. Electroconvulsive therapy (ECT) has shown some effectiveness based on retrospective studies and one open label prospective study. We hypothesized that ECT will reduce NPSs between baseline and after treatment in those with medication-refractory behaviors. METHOD/DESIGN This Canadian prospective multicenter study included MNCD patients admitted to geriatric psychiatry units for the management of refractory NPSs. All treatment-refractory participants suffered from advanced MNCD. We conducted the Neuropsychiatric Inventory-Clinician version and the Pittsburgh Agitation Scale at baseline, and during and after the ECT course. A bitemporal or bifrontal ECT series based on dose titration to 1.5 to 2.5 times seizure threshold was administered. RESULTS Data were collected for 33 patients with a mean age of 73 and categorized with severe MNCD using the Functional Assessment Staging of Alzheimer's Disease scale (stages 6 and 7). The data showed a drop in mean Neuropsychiatric Inventory-Clinician version from 58.36 to 24.58 (P < 0.0001). Mean Neuropsychiatric Inventory agitation subscale dropped from 7.12 to 3.09 (P = 0.007). Mean Neuropsychiatric Inventory aggression subscale dropped from 6.94 to 0.97 (P < 0.0001). There was a concomitant significant decline in Pittsburgh Agitation Scale scores. No participants dropped out because of intolerance of ECT. One participant died from pneumonia, which did not appear related to ECT. CONCLUSIONS In this naturalistic study, ECT was found to be a safe and effective treatment for certain NPSs in people with MNCD. This can translate into improving quality of life.
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Affiliation(s)
| | | | | | - Claire Docherty
- From the Department of Psychiatry, Faculty of Medicine, University of British Columbia
| | - Kaveh Rayani
- Undergraduate Program, Faculty of Medicine, University of British Columbia, Vancouver, British Columbia
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Liu YJ, Liu TT, Jiang LH, Liu Q, Ma ZL, Xia TJ, Gu XP. Identification of hub genes associated with cognition in the hippocampus of Alzheimer's Disease. Bioengineered 2021; 12:9598-9609. [PMID: 34719328 PMCID: PMC8810106 DOI: 10.1080/21655979.2021.1999549] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2022] Open
Abstract
Alzheimer’s Disease (AD) is a neurodegenerative disease featured by cognitive impairment. This bioinformatic analysis was used to identify hub genes related to cognitive dysfunction in AD. The gene expression profile GSE48350 in the hippocampus of AD patients aged >70 years was obtained from the Gene Expression Omnibus (GEO) database. A total of 96 differentially expressed genes (DEGs) were identified, and subjected to Gene Ontology (GO), Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses; a protein–protein interaction (PPI) network was constructed. The DEGs were enriched in synapse-related changes. A protein cluster was teased out of PPI. Furthermore, the cognition ranked the first among all the terms of biological process (BP). Next, 4 of 10 hub genes enriched in cognition were identified. The function of these genes was validated using APP/PS1 mice. Cognitive performance was validated by Morris Water Maze (MWM), and gene expression by RT-qPCR, Cholecystokinin (CCK), Tachykinin precursor 1 (TAC1), Calbindin 1 (CALB1) were downregulated in the hippocampus. These genes can provide new directions in the research of the molecular mechanism of AD.
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Affiliation(s)
- Yu-Jia Liu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China.,Medical School of Nanjing University, Nanjing, Jiangsu Province, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Tian-Tian Liu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China.,Medical School of Nanjing University, Nanjing, Jiangsu Province, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Lin-Hao Jiang
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China.,Medical School of Nanjing University, Nanjing, Jiangsu Province, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Qian Liu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China.,Medical School of Nanjing University, Nanjing, Jiangsu Province, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Zheng-Liang Ma
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
| | - Tian-Jiao Xia
- Medical School of Nanjing University, Nanjing, Jiangsu Province, China.,Jiangsu Key Laboratory of Molecular Medicine, Nanjing University, Nanjing, Jiangsu Province, China
| | - Xiao-Ping Gu
- Department of Anesthesiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing, Jiangsu Province, China
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Epileptic Mechanisms Shared by Alzheimer's Disease: Viewed via the Unique Lens of Genetic Epilepsy. Int J Mol Sci 2021; 22:ijms22137133. [PMID: 34281185 PMCID: PMC8268161 DOI: 10.3390/ijms22137133] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 12/18/2022] Open
Abstract
Our recent work on genetic epilepsy (GE) has identified common mechanisms between GE and neurodegenerative diseases including Alzheimer's disease (AD). Although both disorders are seemingly unrelated and occur at opposite ends of the age spectrum, it is likely there are shared mechanisms and studies on GE could provide unique insights into AD pathogenesis. Neurodegenerative diseases are typically late-onset disorders, but the underlying pathology may have already occurred long before the clinical symptoms emerge. Pathophysiology in the early phase of these diseases is understudied but critical for developing mechanism-based treatment. In AD, increased seizure susceptibility and silent epileptiform activity due to disrupted excitatory/inhibitory (E/I) balance has been identified much earlier than cognition deficit. Increased epileptiform activity is likely a main pathology in the early phase that directly contributes to impaired cognition. It is an enormous challenge to model the early phase of pathology with conventional AD mouse models due to the chronic disease course, let alone the complex interplay between subclinical nonconvulsive epileptiform activity, AD pathology, and cognition deficit. We have extensively studied GE, especially with gene mutations that affect the GABA pathway such as mutations in GABAA receptors and GABA transporter 1. We believe that some mouse models developed for studying GE and insights gained from GE could provide unique opportunity to understand AD. These include the pathology in early phase of AD, endoplasmic reticulum (ER) stress, and E/I imbalance as well as the contribution to cognitive deficit. In this review, we will focus on the overlapping mechanisms between GE and AD, the insights from mutations affecting GABAA receptors, and GABA transporter 1. We will detail mechanisms of E/I imbalance and the toxic epileptiform generation in AD, and the complex interplay between ER stress, impaired membrane protein trafficking, and synaptic physiology in both GE and AD.
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7
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Sciaccaluga M, Megaro A, Bellomo G, Ruffolo G, Romoli M, Palma E, Costa C. An Unbalanced Synaptic Transmission: Cause or Consequence of the Amyloid Oligomers Neurotoxicity? Int J Mol Sci 2021; 22:ijms22115991. [PMID: 34206089 PMCID: PMC8199544 DOI: 10.3390/ijms22115991] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 05/25/2021] [Accepted: 05/26/2021] [Indexed: 12/18/2022] Open
Abstract
Amyloid-β (Aβ) 1-40 and 1-42 peptides are key mediators of synaptic and cognitive dysfunction in Alzheimer's disease (AD). Whereas in AD, Aβ is found to act as a pro-epileptogenic factor even before plaque formation, amyloid pathology has been detected among patients with epilepsy with increased risk of developing AD. Among Aβ aggregated species, soluble oligomers are suggested to be responsible for most of Aβ's toxic effects. Aβ oligomers exert extracellular and intracellular toxicity through different mechanisms, including interaction with membrane receptors and the formation of ion-permeable channels in cellular membranes. These damages, linked to an unbalance between excitatory and inhibitory neurotransmission, often result in neuronal hyperexcitability and neural circuit dysfunction, which in turn increase Aβ deposition and facilitate neurodegeneration, resulting in an Aβ-driven vicious loop. In this review, we summarize the most representative literature on the effects that oligomeric Aβ induces on synaptic dysfunction and network disorganization.
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Affiliation(s)
- Miriam Sciaccaluga
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
- Correspondence: (M.S.); (C.C.); Tel.: +39-0755858180 (M.S.); +39-0755784233 (C.C.)
| | - Alfredo Megaro
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
| | - Giovanni Bellomo
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
| | - Gabriele Ruffolo
- Department of Physiology and Pharmacology, Istituto Pasteur—Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
- IRCCS San Raffaele Pisana, 00166 Rome, Italy
| | - Michele Romoli
- Neurology Unit, Rimini “Infermi” Hospital—AUSL Romagna, 47923 Rimini, Italy;
| | - Eleonora Palma
- Department of Physiology and Pharmacology, Istituto Pasteur—Fondazione Cenci Bolognetti, University of Rome Sapienza, 00185 Rome, Italy; (G.R.); (E.P.)
| | - Cinzia Costa
- Neurology Clinic, Department of Medicine and Surgery, University of Perugia, Santa Maria della Misericordia Hospital, 06132 Perugia, Italy; (A.M.); (G.B.)
- Correspondence: (M.S.); (C.C.); Tel.: +39-0755858180 (M.S.); +39-0755784233 (C.C.)
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Sun Z, Sun L, Tu L. GABAB Receptor-Mediated PI3K/Akt Signaling Pathway Alleviates Oxidative Stress and Neuronal Cell Injury in a Rat Model of Alzheimer’s Disease. J Alzheimers Dis 2020; 76:1513-1526. [PMID: 32651311 DOI: 10.3233/jad-191032] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Zhiqing Sun
- Department of Neurology, Linyi People’s Hospital, Linyi, P.R. China
| | - Lei Sun
- Department of General Surgery, Linyi Hedong District People’s Hospital, Linyi, P.R. China
| | - Lixiang Tu
- Department of Nosocomial Infection Management, Linyi People’s Hospital, Linyi, P.R. China
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Molecular Pathophysiology of Insulin Depletion, Mitochondrial Dysfunction, and Oxidative Stress in Alzheimer’s Disease Brain. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1128:27-44. [DOI: 10.1007/978-981-13-3540-2_3] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
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10
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Reactive Astrocytes as Drug Target in Alzheimer's Disease. BIOMED RESEARCH INTERNATIONAL 2018; 2018:4160247. [PMID: 29888263 PMCID: PMC5977027 DOI: 10.1155/2018/4160247] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 01/14/2018] [Revised: 03/20/2018] [Accepted: 04/10/2018] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease is a neurodegenerative disease characterized by deposition of extracellular amyloid-β, intracellular neurofibrillary tangles, and loss of cortical neurons. However, the mechanism underlying neurodegeneration in Alzheimer's disease (AD) remains to be explored. Many of the researches on AD have been primarily focused on neuronal changes. Current research, however, broadens to give emphasis on the importance of nonneuronal cells, such as astrocytes. Astrocytes play fundamental roles in several cerebral functions and their dysfunctions promote neurodegeneration and, eventually, retraction of neuronal synapses, which leads to cognitive deficits found in AD. Astrocytes become reactive as a result of deposition of Aβ, which in turn have detrimental consequences, including decreased glutamate uptake due to reduced expression of uptake transporters, altered energy metabolism, altered ion homeostasis (K+ and Ca+), increased tonic inhibition, and increased release of cytokines and inflammatory mediators. In this review, recent insights on the involvement of, tonic inhibition, astrocytic glutamate transporters and aquaporin in the pathogenesis of Alzheimer's disease are provided. Compounds which increase expression of GLT1 have showed efficacy for AD in preclinical studies. Tonic inhibition mediated by GABA could also be a promising target and drugs that block the GABA synthesizing enzyme, MAO-B, have shown efficacy. However, there are contradictory evidences on the role of AQP4 in AD.
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Circuit-specific and neuronal subcellular-wide E-I balance in cortical pyramidal cells. Sci Rep 2018; 8:3971. [PMID: 29507308 PMCID: PMC5838226 DOI: 10.1038/s41598-018-22314-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2017] [Accepted: 02/20/2018] [Indexed: 11/08/2022] Open
Abstract
We used ChR2-assisted circuit mapping (CRACM) to examine neuronal/compartmental excitatory and inhibitory synaptic balance (E-I balance) in pyramidal cells (PCs) located in several brain regions (including both neocortices and paleocortices). Within the vS1, different inputs on the same neurons, or the same inputs formed on different targets, induced different E/I ratios. E/I ratios in PCs from different regions were largely different. Chemogenetic silencing of somatostatin (SOM)- or parvalbumin (PV)-containing interneurons (INs) while optogenetically activating long-range M1 inputs demonstrated differential contribution of PV and SOM INs to the E/I ratios in a layer-specific manner in S1. Our results thus demonstrate that there are both universal subcellular-wide E-I balance within single PC and high specificity in the value of E/I ratios across different circuits (i.e. visual, somatosensory, piriform and hippocampal). Specificity of E/I balance are likely caused by unique glutamatergic innervation of interneurons. The dichotomy of high specificity and generalization of subcellular E-I balance in different circuits forms the basis for further understanding of neuronal computation under physiological conditions and various neuro-psychiatric disease-states.
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