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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 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] [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 , Singapore 117597, Singapore
- Neurobiology Programme, Life Sciences Institute, National University of Singapore , Singapore 119077, Singapore
| | - Zijun Wang
- 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 119077, 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 119077, Singapore
- Healthy Longevity Translational Research Programme, Yong Loo Lin School of Medicine, National University of Singapore , Singapore 117597, Singapore
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Shanks HRC, Chen K, Reiman EM, Blennow K, Cummings JL, Massa SM, Longo FM, Börjesson-Hanson A, Windisch M, Schmitz TW. p75 neurotrophin receptor modulation in mild to moderate Alzheimer disease: a randomized, placebo-controlled phase 2a trial. Nat Med 2024:10.1038/s41591-024-02977-w. [PMID: 38760589 DOI: 10.1038/s41591-024-02977-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2023] [Accepted: 04/04/2024] [Indexed: 05/19/2024]
Abstract
p75 neurotrophin receptor (p75NTR) signaling pathways substantially overlap with degenerative networks active in Alzheimer disease (AD). Modulation of p75NTR with the first-in-class small molecule LM11A-31 mitigates amyloid-induced and pathological tau-induced synaptic loss in preclinical models. Here we conducted a 26-week randomized, placebo-controlled, double-blinded phase 2a safety and exploratory endpoint trial of LM11A-31 in 242 participants with mild to moderate AD with three arms: placebo, 200 mg LM11A-31 and 400 mg LM11A-31, administered twice daily by oral capsules. This trial met its primary endpoint of safety and tolerability. Within the prespecified secondary and exploratory outcome domains (structural magnetic resonance imaging, fluorodeoxyglucose positron-emission tomography and cerebrospinal fluid biomarkers), significant drug-placebo differences were found, consistent with the hypothesis that LM11A-31 slows progression of pathophysiological features of AD; no significant effect of active treatment was observed on cognitive tests. Together, these results suggest that targeting p75NTR with LM11A-31 warrants further investigation in larger-scale clinical trials of longer duration. EU Clinical Trials registration: 2015-005263-16 ; ClinicalTrials.gov registration: NCT03069014 .
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Affiliation(s)
- Hayley R C Shanks
- Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
- Robarts Research Institute, Western University, London, Ontario, Canada.
- Western Institute for Neuroscience, Western University, London, Ontario, Canada.
| | - Kewei Chen
- Banner Alzheimer's Institute, Phoenix, AZ, USA
- College of Medicine-Phoenix, University of Arizona, Phoenix, AZ, USA
- College of Health Solutions, Arizona State University, Downtown, Phoenix, AZ, USA
| | - Eric M Reiman
- Banner Alzheimer's Institute, Phoenix, AZ, USA
- College of Medicine-Phoenix, University of Arizona, Phoenix, AZ, USA
- Translational Genomics Research Institute, Phoenix, AZ, USA
- Arizona Alzheimer's Consortium, Phoenix, AZ, USA
- ASU-Banner Neurodegenerative Disease Research Center, Arizona State University, Tempe, AZ, USA
| | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Jeffrey L Cummings
- Chambers-Grundy Center for Transformative Neuroscience, Department of Brain Health, School of Integrated Health Sciences, University of Nevada Las Vegas (UNLV), Las Vegas, NV, USA
| | - Stephen M Massa
- San Francisco Veterans Affairs Health Care System, San Francisco, CA, USA
- Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | | | - Anne Börjesson-Hanson
- Clinical Trials, Department of Aging, Karolinska University Hospital, Stockholm, Sweden
| | | | - Taylor W Schmitz
- Schulich School of Medicine and Dentistry, Western University, London, Ontario, Canada.
- Robarts Research Institute, Western University, London, Ontario, Canada.
- Western Institute for Neuroscience, Western University, London, Ontario, Canada.
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Liu G, He M, Wu C, Lv P, Sun H, Wang H, Xin X, Liao H. Axonal injury mediated by neuronal p75NTR/TRAF6/JNK pathway contributes to cognitive impairment after repetitive mTBI. Exp Neurol 2024; 372:114618. [PMID: 38029807 DOI: 10.1016/j.expneurol.2023.114618] [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: 10/07/2023] [Revised: 11/06/2023] [Accepted: 11/20/2023] [Indexed: 12/01/2023]
Abstract
Repetitive mild traumatic brain injury (rmTBI) is one of the leading causes of cognitive disorders. The impairment of axonal integrity induced by rmTBI is speculated to underlie the progression of cognitive dysfunction. However, few studies have uncovered the cellular mechanism regulating axonal impairment. In this study, we showed that after rmTBI, the activation of neuronal p75NTR signaling contributes to abnormal axonal morphology and impaired axonal transport, which further leads to cognitive dysfunction in mice. By neuron-specific knockdown of p75NTR or treatment with p75NTR inhibitor LM11A-31, we observed better recovery of axonal integrity and cognitive function after brain trauma. Further analysis revealed that p75NTR relies on its adaptor protein TRAF6 to activate downstream signaling via TAK1 and JNK. Overall, our results provide novel insight into the role of neuronal p75NTR in axonal injury and suggest that p75NTR may be a promising target for cognitive function recovery after rmTBI.
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Affiliation(s)
- Gang Liu
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China
| | - Meijun He
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China
| | - Chaoran Wu
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China
| | - Pin Lv
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China
| | - Hao Sun
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China
| | - Heng Wang
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China
| | - Xiaoyan Xin
- Department of Radiology, Nanjing Drum Tower Hospital, The Affiliated Hospital of Nanjing University Medical School, Nanjing 210008, China.
| | - Hong Liao
- New drug screening center, Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing 210009, China; Chongqing Innovation Institute of China Pharmaceutical University, Chongqing 401135, China.
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Danelon V, Garret-Thomson SC, Almo SC, Lee FS, Hempstead BL. Immune activation of the p75 neurotrophin receptor: implications in neuroinflammation. Front Mol Neurosci 2023; 16:1305574. [PMID: 38106879 PMCID: PMC10722190 DOI: 10.3389/fnmol.2023.1305574] [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: 10/02/2023] [Accepted: 11/10/2023] [Indexed: 12/19/2023] Open
Abstract
Despite structural similarity with other tumor necrosis factor receptor superfamily (TNFRSF) members, the p75 neurotrophin receptor (p75NTR, TNFR16) mediates pleiotropic biological functions not shared with other TNFRs. The high level of p75NTR expression in the nervous system instead of immune cells, its utilization of co-receptors, and its interaction with soluble dimeric, rather than soluble or cell-tethered trimeric ligands are all characteristics which distinguish it from most other TNFRs. Here, we compare these attributes to other members of the TNFR superfamily. In addition, we describe the recent evolutionary adaptation in B7-1 (CD80), an immunoglobulin (Ig) superfamily member, which allows engagement to neuronally-expressed p75NTR. B7-1-mediated binding to p75NTR occurs in humans and other primates, but not lower mammals due to specific sequence changes that evolved recently in primate B7-1. This discovery highlights an additional mechanism by which p75NTR can respond to inflammatory cues and trigger synaptic elimination in the brain through engagement of B7-1, which was considered to be immune-restricted. These observations suggest p75NTR does share commonality with other immune co-modulatory TNFR family members, by responding to immunoregulatory cues. The evolution of primate B7-1 to bind and elicit p75NTR-mediated effects on neuronal morphology and function are discussed in relationship to immune-driven modulation of synaptic actions during injury or inflammation.
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Affiliation(s)
- Victor Danelon
- Department of Medicine, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, United States
| | | | - Steven C. Almo
- Department of Biochemistry, Albert Einstein College of Medicine, Bronx, NY, United States
| | - Francis S. Lee
- Department of Psychiatry, Weill Cornell Medicine, New York, NY, United States
| | - Barbara L. Hempstead
- Department of Medicine, Weill Cornell Graduate School of Medical Sciences, Weill Cornell Medicine, New York, NY, United States
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Jung HY, Kwon HJ, Hahn KR, Kim W, Yoo DY, Yoon YS, Kim DW, Hwang IK. Tat-heat shock protein 10 ameliorates age-related phenotypes by facilitating neuronal plasticity and reducing age-related genes in the hippocampus. Aging (Albany NY) 2023; 15:12723-12737. [PMID: 38011257 DOI: 10.18632/aging.205182] [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: 12/13/2022] [Accepted: 10/06/2023] [Indexed: 11/29/2023]
Abstract
We investigated the effects of heat shock protein 10 (HSP10) protein on memory function, hippocampal neurogenesis, and other related genes/proteins in adult and aged mice. To translocate the HSP10 protein into the hippocampus, the Tat-HSP10 fusion protein was synthesized, and Tat-HSP10, not HSP10, was successfully delivered into the hippocampus based on immunohistochemistry and western blotting. Tat-HSP10 (0.5 or 2.0 mg/kg) or HSP10 (control protein, 2.0 mg/kg) was administered daily to 3- and 21-month-old mice for 3 months, and observed the senescence maker P16 was significantly increased in aged mice and the treatment with Tat-HSP10 significantly decreased P16 expression in the hippocampus of aged mice. In novel object recognition and Morris water maze tests, aged mice demonstrated decreases in exploratory preferences, exploration time, distance moved, number of object contacts, and escape latency compared to adult mice. Treatment with Tat-HSP10 significantly improved exploratory preferences, the number of object contacts, and the time spent swimming in the target quadrant in aged mice but not adults. Administration of Tat-HSP10 increased the number of proliferating cells and differentiated neuroblasts in the dentate gyrus of adult and aged mice compared to controls, as determined by immunohistochemical staining for Ki67 and doublecortin, respectively. Additionally, Tat-HSP10 treatment significantly mitigated the reduction in sirtuin 1 mRNA level, N-methyl-D-aspartate receptor 1, and postsynaptic density 95 protein levels in the hippocampus of aged mice. In contrast, Tat-HSP10 treatment significantly increased sirtuin 3 protein levels in both adult and aged mouse hippocampus. These suggest that Tat-HSP10 can potentially reduce hippocampus-related aging phenotypes.
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Affiliation(s)
- Hyo Young Jung
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, South Korea
- Department of Veterinary Medicine and Institute of Veterinary Science, Chungnam National University, Daejeon 34134, South Korea
| | - Hyun Jung Kwon
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung 25457, South Korea
- Department of Biomedical Sciences, and Research Institute for Bioscience and Biotechnology, Hallym University, Chuncheon 24252, South Korea
| | - Kyu Ri Hahn
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, South Korea
| | - Woosuk Kim
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, South Korea
- Department of Anatomy, College of Veterinary Medicine, and Veterinary Science Research Institute, Konkuk University, Seoul 05030, South Korea
| | - Dae Young Yoo
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, South Korea
- Department of Anatomy and Convergence Medical Science, Institute of Health Sciences, College of Medicine, Gyeongsang National University, Jinju 52727, South Korea
| | - Yeo Sung Yoon
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, South Korea
| | - Dae Won Kim
- Department of Biochemistry and Molecular Biology, Research Institute of Oral Sciences, College of Dentistry, Gangneung-Wonju National University, Gangneung 25457, South Korea
| | - In Koo Hwang
- Department of Anatomy and Cell Biology, College of Veterinary Medicine, and Research Institute for Veterinary Science, Seoul National University, Seoul 08826, South Korea
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Bakhtiarzadeh F, Shahpasand K, Shojaei A, Fathollahi Y, Roohi N, Barkley V, Mirnajafi-Zadeh J. Age-dependent Effects of Dopamine on Working Memory and Synaptic Plasticity in Hippocampal CA3-CA1 Synapses in Mice. Neuroscience 2023; 532:14-22. [PMID: 37741356 DOI: 10.1016/j.neuroscience.2023.09.008] [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: 05/01/2023] [Revised: 09/15/2023] [Accepted: 09/18/2023] [Indexed: 09/25/2023]
Abstract
Normal aging in mammals is accompanied by a decline in learning and memory. Dopamine plays a vital role in regulating cognitive functions, but it declines with age: During non-pathological aging, dopamine levels, receptors, and transporters decrease. Regarding the role of the dopaminergic system's changes in old age, we examined the effect of age and applied dopamine on working memory, synaptic transmission, and long-term potentiation (LTP) induction and maintenance in young adult and mature adult mice. We employed the Y-maze spontaneous alteration test to evaluate working memory. Maturation had no observed effect on working memory performance. Interestingly, working memory performance increased following intracerebroventricular administration of dopamine only in mature adult mice. We employed evoked field potential recording (in vitro) to assess the effects of age and maturation on the long-term potentiation (LTP) induction and maintenance. There was no difference in LTP induction and maintenance between young and mature adult mice before dopamine application. However, the application of dopamine on mature adult murine slices increased LTP magnitude compared to slices from young adults. According to the obtained results, it may be concluded that hippocampal neural excitability increased in mature adult subjects, and application of dopamine abolished the difference in neural excitability among young mature and adult mature groups; which was accompanied with increment of working memory and synaptic potentiation in mature adult animals.
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Affiliation(s)
- Fatemeh Bakhtiarzadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Koorosh Shahpasand
- Department of Brain and Cognitive Sciences, Cell Science Research Center, Royan Institute for Stem Cell Biology and Technology, ACECR, Tehran, Iran
| | - Amir Shojaei
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran
| | - Yaghoub Fathollahi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Nahid Roohi
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran
| | - Vicrotia Barkley
- Department of Anesthesia and Pain Management, Toronto General Hospital, University Health Network, Toronto, Canada
| | - Javad Mirnajafi-Zadeh
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran; Institute for Brain Sciences and Cognition, Tarbiat Modares University, Tehran, Iran.
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Brito DVC, Esteves F, Rajado AT, Silva N, Araújo I, Bragança J, Castelo-Branco P, Nóbrega C. Assessing cognitive decline in the aging brain: lessons from rodent and human studies. NPJ AGING 2023; 9:23. [PMID: 37857723 PMCID: PMC10587123 DOI: 10.1038/s41514-023-00120-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/31/2023] [Indexed: 10/21/2023]
Abstract
As life expectancy continues to increase worldwide, age-related dysfunction will largely impact our societies in the future. Aging is well established to promote the deterioration of cognitive function and is the primary risk factor for the development of prevalent neurological disorders. Even in the absence of dementia, age-related cognitive decline impacts specific types of memories and brain structures in humans and animal models. Despite this, preclinical and clinical studies that investigate age-related changes in brain physiology often use largely different methods, which hinders the translational potential of findings. This review seeks to integrate what is known about age-related changes in the brain with analogue cognitive tests used in humans and rodent studies, ranging from "pen and paper" tests to virtual-reality-based paradigms. Finally, we draw parallels between the behavior paradigms used in research compared to the enrollment into clinical trials that aim to study age-related cognitive decline.
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Affiliation(s)
- D V C Brito
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal
- Algarve Biomedical Center- (ABC), Campus Gambelas, Bld.2, Faro, Portugal
| | - F Esteves
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal
- Algarve Biomedical Center- (ABC), Campus Gambelas, Bld.2, Faro, Portugal
| | - A T Rajado
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal
- Algarve Biomedical Center- (ABC), Campus Gambelas, Bld.2, Faro, Portugal
| | - N Silva
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal
- Algarve Biomedical Center- (ABC), Campus Gambelas, Bld.2, Faro, Portugal
| | - I Araújo
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal
- Faculty of Medicine and Biomedical Sciences (FMCB), University of Algarve, Gambelas Campus, Bld.2, Faro, Portugal
- Champalimaud Research Program, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - J Bragança
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal
- Algarve Biomedical Center- (ABC), Campus Gambelas, Bld.2, Faro, Portugal
- Faculty of Medicine and Biomedical Sciences (FMCB), University of Algarve, Gambelas Campus, Bld.2, Faro, Portugal
- Champalimaud Research Program, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - P Castelo-Branco
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal
- Algarve Biomedical Center- (ABC), Campus Gambelas, Bld.2, Faro, Portugal
- Faculty of Medicine and Biomedical Sciences (FMCB), University of Algarve, Gambelas Campus, Bld.2, Faro, Portugal
- Champalimaud Research Program, Champalimaud Centre for the Unknown, Lisbon, Portugal
| | - C Nóbrega
- Algarve Biomedical Center-Research Institute (ABC-RI), Campus Gambelas, Bld.2, Faro, Portugal.
- Algarve Biomedical Center- (ABC), Campus Gambelas, Bld.2, Faro, Portugal.
- Faculty of Medicine and Biomedical Sciences (FMCB), University of Algarve, Gambelas Campus, Bld.2, Faro, Portugal.
- Champalimaud Research Program, Champalimaud Centre for the Unknown, Lisbon, Portugal.
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Ramdeo KR, Fahnestock M, Gibala M, Selvaganapathy PR, Lee J, Nelson AJ. The Effects of Exercise on Synaptic Plasticity in Individuals With Mild Cognitive Impairment: Protocol for a Pilot Intervention Study. JMIR Res Protoc 2023; 12:e50030. [PMID: 37851488 PMCID: PMC10620638 DOI: 10.2196/50030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 09/07/2023] [Accepted: 09/11/2023] [Indexed: 10/19/2023] Open
Abstract
BACKGROUND Mild cognitive impairment (MCI) is a syndrome preceding more severe impairment characterized by dementia. MCI affects an estimated 15% to 20% of people older than 65 years. Nonpharmacological interventions including exercise are recommended as part of overall MCI management based on the positive effects of exercise on cognitive performance. Interval training involves brief intermittent bouts of exercise interspersed with short recovery periods. This type of exercise promotes cognitive improvement and can be performed in individuals with MCI. Synaptic plasticity can be assessed in vivo by the neurophysiological response to repetitive transcranial magnetic stimulation (rTMS). A method to assess synaptic plasticity uses an intermittent theta burst stimulation (iTBS), which is a patterned form of rTMS. Individuals with MCI have decreased responses to iTBS, reflecting reduced synaptic plasticity. It is unknown whether interval training causes changes in synaptic plasticity in individuals living with MCI. OBJECTIVE This research will determine whether interval training performed using a cycle ergometer enhances synaptic plasticity in individuals with MCI. The three aims are to (1) quantify synaptic plasticity after interval training performed at a self-determined intensity in individuals with MCI; (2) determine whether changes in synaptic plasticity correlate with changes in serum brain-derived neurotrophic factor, osteocalcin, and cognition; and (3) assess participant compliance to the exercise schedule. METHODS 24 individuals diagnosed with MCI will be recruited for assignment to 1 of the 2 equally sized groups: exercise and no exercise. The exercise group will perform exercise 3 times per week for 4 weeks. Synaptic plasticity will be measured before and following the 4-week intervention. At these time points, synaptic plasticity will be measured as the response to single-pulse TMS, reflected as the percent change in the average amplitude of 20 motor-evoked potentials before and after an iTBS rTMS protocol, which is used to induce synaptic plasticity. In addition, individuals will complete a battery of cognitive assessments and provide a blood sample from the antecubital vein to determine serum brain-derived neurotrophic factor and osteocalcin. RESULTS The study began in September 2023. CONCLUSIONS The proposed research is the first to assess whether synaptic plasticity is enhanced after exercise training in individuals with MCI. If exercise does indeed modify synaptic plasticity, this will create a new avenue by which we can study and manipulate neural plasticity in these individuals. TRIAL REGISTRATION ClinicalTrials.gov NCT05663918; https://clinicaltrials.gov/study/NCT05663918. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID) PRR1-10.2196/50030.
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Affiliation(s)
- Karishma R Ramdeo
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | - Margaret Fahnestock
- Department of Psychiatry & Behavioural Neurosciences, McMaster University, Hamilton, ON, Canada
| | - Martin Gibala
- Department of Kinesiology, McMaster University, Hamilton, ON, Canada
| | | | - Justin Lee
- Department of Geriatric Medicine, McMaster University, Hamilton, ON, Canada
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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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10
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Jiang F, Bello ST, Gao Q, Lai Y, Li X, He L. Advances in the Electrophysiological Recordings of Long-Term Potentiation. Int J Mol Sci 2023; 24:ijms24087134. [PMID: 37108295 PMCID: PMC10138642 DOI: 10.3390/ijms24087134] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2023] [Revised: 04/01/2023] [Accepted: 04/06/2023] [Indexed: 04/29/2023] Open
Abstract
Understanding neuronal firing patterns and long-term potentiation (LTP) induction in studying learning, memory, and neurological diseases is critical. However, recently, despite the rapid advancement in neuroscience, we are still constrained by the experimental design, detection tools for exploring the mechanisms and pathways involved in LTP induction, and detection ability of neuronal action potentiation signals. This review will reiterate LTP-related electrophysiological recordings in the mammalian brain for nearly 50 years and explain how excitatory and inhibitory neural LTP results have been detected and described by field- and single-cell potentials, respectively. Furthermore, we focus on describing the classic model of LTP of inhibition and discuss the inhibitory neuron activity when excitatory neurons are activated to induce LTP. Finally, we propose recording excitatory and inhibitory neurons under the same experimental conditions by combining various electrophysiological technologies and novel design suggestions for future research. We discussed different types of synaptic plasticity, and the potential of astrocytes to induce LTP also deserves to be explored in the future.
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Affiliation(s)
- Feixu Jiang
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
| | | | - Qianqian Gao
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
| | - Yuanying Lai
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
| | - Xiao Li
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
- Research Institute of City University of Hong Kong, Shenzhen 518057, China
| | - Ling He
- Department of Neuroscience, City University of Hong Kong, Kowloon, Hong Kong
- Research Institute of City University of Hong Kong, Shenzhen 518057, China
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11
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The Nerve Growth Factor Receptor (NGFR/p75 NTR): A Major Player in Alzheimer's Disease. Int J Mol Sci 2023; 24:ijms24043200. [PMID: 36834612 PMCID: PMC9965628 DOI: 10.3390/ijms24043200] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 02/01/2023] [Accepted: 02/03/2023] [Indexed: 02/09/2023] Open
Abstract
Alzheimer's disease (AD) represents the most prevalent type of dementia in elderly people, primarily characterized by brain accumulation of beta-amyloid (Aβ) peptides, derived from Amyloid Precursor Protein (APP), in the extracellular space (amyloid plaques) and intracellular deposits of the hyperphosphorylated form of the protein tau (p-tau; tangles or neurofibrillary aggregates). The Nerve growth factor receptor (NGFR/p75NTR) represents a low-affinity receptor for all known mammalians neurotrophins (i.e., proNGF, NGF, BDNF, NT-3 e NT-4/5) and it is involved in pathways that determine both survival and death of neurons. Interestingly, also Aβ peptides can blind to NGFR/p75NTR making it the "ideal" candidate in mediating Aβ-induced neuropathology. In addition to pathogenesis and neuropathology, several data indicated that NGFR/p75NTR could play a key role in AD also from a genetic perspective. Other studies suggested that NGFR/p75NTR could represent a good diagnostic tool, as well as a promising therapeutic target for AD. Here, we comprehensively summarize and review the current experimental evidence on this topic.
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12
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Li X, Zhai Q, Gou X, Quan M, Li Y, Zhang X, Deng B, Tian Y, Wang Q, Hou L. Involvement of Paired Immunoglobulin-Like Receptor B in Cognitive Dysfunction Through Hippocampal-Dependent Synaptic Plasticity Impairments in Mice Subjected to Chronic Sleep Restriction. Mol Neurobiol 2023; 60:1132-1149. [PMID: 36417104 PMCID: PMC9899186 DOI: 10.1007/s12035-022-03127-4] [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: 07/12/2022] [Accepted: 11/04/2022] [Indexed: 11/24/2022]
Abstract
Sleep loss is often associated with cognitive dysfunction. Alterations in the structure and function of synapses in the hippocampus are thought to underlie memory storage. Paired immunoglobulin-like receptor B (PirB) plays a negative role in various neurological diseases by inhibiting axon regeneration and synaptic plasticity. However, the contributions of PirB to the mechanisms underlying the changes in synaptic plasticity after sleep loss that ultimately promote deficits in cognitive function have not been well elucidated. Here, we showed that chronic sleep restriction (CSR) mice displayed cognitive impairment and synaptic deficits accompanied by upregulation of PirB expression in the hippocampus. Mechanistically, PirB caused the dysregulation of actin through the RhoA/ROCK2/LIMK1/cofilin signalling pathway, leading to abnormal structural and functional plasticity, which in turn resulted in cognitive dysfunction. PirB knockdown alleviated synaptic deficits and cognitive impairment after CSR by inhibiting the RhoA/ROCK2/LIMK1/cofilin signalling pathway. Moreover, we found that fasudil, a widely used ROCK2 inhibitor, could mimic the beneficial effect of PirB knockdown and ameliorate synaptic deficits and cognitive impairment, further demonstrating that PirB induced cognitive dysfunction after CSR via the RhoA/ROCK2/LIMK1/cofilin signalling pathway. Our study sheds new light on the role of PirB as an important mediator in modulating the dysfunction of synaptic plasticity and cognitive function via the RhoA/ROCK2/LIMK1/cofilin signalling pathway, which indicated that hippocampal PirB is a promising therapeutic target for counteracting cognitive impairment after CSR. This illustration depicts the signalling pathway by PirB in mediating cognitive impairment and synaptic deficits in CSR mice. In the hippocampus of CSR mice, the expression level of PirB was significantly increased. In addition, CSR increases RhoA and ROCK2 levels and reduces levels of both LIMK1 and cofilin phosphorylation. PirB knockdown reverses cognitive impairment and synaptic plasticity disorders caused by CSR through the RhoA/ROCK2/LIMK1/cofilin signalling pathway.
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Affiliation(s)
- Xuying Li
- Department of Anesthesiology, Xiang’an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102 Fujian China ,Department of Anesthesiology, Affiliated Haikou Hospital, Xiangya Medical College of Central South University, Haikou, 570000 Hainan China
| | - Qian Zhai
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, 710061 Shaanxi China
| | - Xingchun Gou
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, 710021 Shaanxi China
| | - Minxue Quan
- Department of Anesthesiology, Xiang’an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102 Fujian China
| | - Yansong Li
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, 710061 Shaanxi China
| | - Xiaohua Zhang
- Shaanxi Key Laboratory of Brain Disorders & Institute of Basic and Translational Medicine, Xi’an Medical University, Xi’an, 710021 Shaanxi China
| | - Bin Deng
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, 710061 Shaanxi China
| | - Yi Tian
- Department of Anesthesiology, Affiliated Haikou Hospital, Xiangya Medical College of Central South University, Haikou, 570000 Hainan China
| | - Qiang Wang
- Department of Anesthesiology & Center for Brain Science, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, 710061 Shaanxi China
| | - Lichao Hou
- Department of Anesthesiology, Xiang’an Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, 361102 Fujian China
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13
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Wu DP, Zhao YD, Yan QQ, Liu LL, Wei YS, Huang JL. Circular RNAs: emerging players in brain aging and neurodegenerative diseases. J Pathol 2023; 259:1-9. [PMID: 36264226 DOI: 10.1002/path.6021] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 10/06/2022] [Accepted: 10/17/2022] [Indexed: 11/06/2022]
Abstract
Brain aging is closely related to neurodegenerative diseases. Circular RNAs (circRNAs) are a type of conserved RNAs with covalently closed continuous loops. Emerging evidence has shown that circRNAs are implicated in the biology of brain aging and the pathology of age-related neurodegenerative diseases. Here, we summarize current studies on circRNAs associated with brain aging and neurodegenerative diseases by discussing their expression features, pathophysiological roles, and mechanisms of action. We also discuss the potential challenges of circRNA-based therapy against brain aging and neurodegenerative diseases, as well as their potential as diagnostic biomarkers of neurodegenerative diseases. The review provides insights into current progress in the functions of circRNAs in the process of brain aging and neurodegenerative diseases. © 2022 The Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Deng-Pan Wu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Pharmacy School, Xuzhou Medical University, Xuzhou, Jiangsu, PR China.,Department of Pharmacology, Xuzhou Medical University, Xuzhou, Jiangsu, PR China
| | - Yuan-Dan Zhao
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Pharmacy School, Xuzhou Medical University, Xuzhou, Jiangsu, PR China
| | - Qiu-Qing Yan
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Pharmacy School, Xuzhou Medical University, Xuzhou, Jiangsu, PR China
| | - Ling-Ling Liu
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Pharmacy School, Xuzhou Medical University, Xuzhou, Jiangsu, PR China
| | - Yan-Su Wei
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Pharmacy School, Xuzhou Medical University, Xuzhou, Jiangsu, PR China
| | - Jin-Lan Huang
- Jiangsu Key Laboratory of New Drug Research and Clinical Pharmacy, Pharmacy School, Xuzhou Medical University, Xuzhou, Jiangsu, PR China.,Department of Pharmacology, Xuzhou Medical University, Xuzhou, Jiangsu, PR China
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14
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Suzuki K, Ohi Y, Sato T, Tsuda Y, Madokoro Y, Mizuno M, Adachi K, Uchida Y, Haji A, Ojika K, Matsukawa N. Reduction of glutamatergic activity through cholinergic dysfunction in the hippocampus of hippocampal cholinergic neurostimulating peptide precursor protein knockout mice. Sci Rep 2022; 12:19161. [PMID: 36357544 PMCID: PMC9649636 DOI: 10.1038/s41598-022-23846-x] [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: 09/24/2022] [Accepted: 11/07/2022] [Indexed: 11/11/2022] Open
Abstract
Cholinergic activation can enhance glutamatergic activity in the hippocampus under pathologic conditions, such as Alzheimer's disease. The aim of the present study was to elucidate the relationship between glutamatergic neural functional decline and cholinergic neural dysfunction in the hippocampus. We report the importance of hippocampal cholinergic neurostimulating peptide (HCNP) in inducing acetylcholine synthesis in the medial septal nucleus. Here, we demonstrate that HCNP-precursor protein (pp) knockout (KO) mice electrophysiologically presented with glutamatergic dysfunction in the hippocampus with age. The impairment of cholinergic function via a decrease in vesicular acetylcholine transporter in the pre-synapse with reactive upregulation of the muscarinic M1 receptor may be partly involved in glutamatergic dysfunction in the hippocampus of HCNP-pp KO mice. The results, in combination with our previous reports that show the reduction of hippocampal theta power through a decrease of a region-specific choline acetyltransferase in the stratum oriens of CA1 and the decrease of acetylcholine concentration in the hippocampus, may indicate the defined cholinergic dysfunction in HCNP-pp KO mice. This may also support that HCNP-pp KO mice are appropriate genetic models for cholinergic functional impairment in septo-hippocampal interactions. Therefore, according to the cholinergic hypothesis, the model mice might are potential partial pathological animal models for Alzheimer's disease.
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Affiliation(s)
- Kengo Suzuki
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Yoshiaki Ohi
- grid.411253.00000 0001 2189 9594Laboratory of Neuropharmacology, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-Ku, Nagoya, 464-8650 Japan
| | - Toyohiro Sato
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Yo Tsuda
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Yuta Madokoro
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Masayuki Mizuno
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Kenichi Adachi
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Yuto Uchida
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Akira Haji
- grid.411253.00000 0001 2189 9594Laboratory of Neuropharmacology, School of Pharmacy, Aichi Gakuin University, 1-100 Kusumoto, Chikusa-Ku, Nagoya, 464-8650 Japan
| | - Kosei Ojika
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
| | - Noriyuki Matsukawa
- grid.260433.00000 0001 0728 1069Department of Neurology, Graduate School of Medical Sciences, Nagoya City University, 1 Kawasumi, Mizuho-Ku, Nagoya, 467-8602 Japan
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15
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Schirò G, Iacono S, Ragonese P, Aridon P, Salemi G, Balistreri CR. A Brief Overview on BDNF-Trk Pathway in the Nervous System: A Potential Biomarker or Possible Target in Treatment of Multiple Sclerosis? Front Neurol 2022; 13:917527. [PMID: 35911894 PMCID: PMC9332890 DOI: 10.3389/fneur.2022.917527] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 06/01/2022] [Indexed: 01/09/2023] Open
Abstract
The growing incidence of neurodegenerative disorders in our populations is leading the research to identify potential biomarkers and targets for facilitating their early management and treatments. Biomarkers represent the crucial indicators of both physiological and pathological processes. Specific changes in molecular and cellular mechanisms of physiological processes result in biochemical alterations at systemic level, which can give us comprehensive information regarding the nature of any disease. In addition, any disease biomarker should be specific and reliable, able to consent of distinguishing the physiological condition of a tissue, organ, or system from disease, and be diverse among the various diseases, or subgroups or phenotypes of them. Accordingly, biomarkers can predict chances for diseases, facilitate their early diagnosis, and set guidelines for the development of new therapies for treating diseases and disease-making process. Here, we focus our attention on brain neurotrophic factor (BDNF)–tropomyosin receptor kinase (Trk) pathway, describing its multiple roles in the maintenance of central nervous system (CNS) health, as well as its implication in the pathogenesis of multiple sclerosis (MS). In addition, we also evidence the features of such pathway, which make of it a potential MS biomarker and therapeutic target.
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Affiliation(s)
- Giuseppe Schirò
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Salvatore Iacono
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Paolo Ragonese
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
- Paolo Ragonese
| | - Paolo Aridon
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
| | - Giuseppe Salemi
- Unit of Neurology, Department of Biomedicine, Neurosciences and Advanced Diagnostics, University of Palermo, Palermo, Italy
- Giuseppe Salemi
| | - Carmela Rita Balistreri
- Cellular and Molecular Laboratory, Department of Biomedicine, Neuroscience and Advanced Diagnostics (Bi.N.D.), University of Palermo, Palermo, Italy
- *Correspondence: Carmela Rita Balistreri ; orcid.org/0000-0002-5393-1007
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Ridderinkhof KR, Krugers HJ. Horizons in Human Aging Neuroscience: From Normal Neural Aging to Mental (Fr)Agility. Front Hum Neurosci 2022; 16:815759. [PMID: 35845248 PMCID: PMC9277589 DOI: 10.3389/fnhum.2022.815759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2021] [Accepted: 05/19/2022] [Indexed: 11/13/2022] Open
Abstract
While aging is an important risk factor for neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease, age-related cognitive decline can also manifest without apparent neurodegenerative changes. In this review, we discuss molecular, cellular, and network changes that occur during normal aging in the absence of neurodegenerative disease. Emerging findings reveal that these changes include metabolic alterations, oxidative stress, DNA damage, inflammation, calcium dyshomeostasis, and several other hallmarks of age-related neural changes that do not act on their own, but are often interconnected and together may underlie age-related alterations in brain plasticity and cognitive function. Importantly, age-related cognitive decline may not be reduced to a single neurobiological cause, but should instead be considered in terms of a densely connected system that underlies age-related cognitive alterations. We speculate that a decline in one hallmark of neural aging may trigger a decline in other, otherwise thus far stable subsystems, thereby triggering a cascade that may at some point also incur a decline of cognitive functions and mental well-being. Beyond studying the effects of these factors in isolation, considerable insight may be gained by studying the larger picture that entails a representative collection of such factors and their interactions, ranging from molecules to neural networks. Finally, we discuss some potential interventions that may help to prevent these alterations, thereby reducing cognitive decline and mental fragility, and enhancing mental well-being, and healthy aging.
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Affiliation(s)
- K Richard Ridderinkhof
- Department of Psychology, University of Amsterdam, Amsterdam, Netherlands
- Amsterdam Center for Brain and Cognition (ABC), University of Amsterdam, Amsterdam, Netherlands
| | - Harm J Krugers
- Amsterdam Center for Brain and Cognition (ABC), University of Amsterdam, Amsterdam, Netherlands
- SILS-CNS, Faculty of Science, University of Amsterdam, Amsterdam, Netherlands
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17
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Fading memories in aging and neurodegeneration: Is p75 neurotrophin receptor a culprit? Ageing Res Rev 2022; 75:101567. [PMID: 35051645 DOI: 10.1016/j.arr.2022.101567] [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: 09/14/2021] [Revised: 12/12/2021] [Accepted: 01/12/2022] [Indexed: 11/22/2022]
Abstract
Aging and age-related neurodegenerative diseases have become one of the major concerns in modern times as cognitive abilities tend to decline when we get older. It is well known that the main cause of this age-related cognitive deficit is due to aberrant changes in cellular, molecular circuitry and signaling pathways underlying synaptic plasticity and neuronal connections. The p75 neurotrophin receptor (p75NTR) is one of the important mediators regulating the fate of the neurons in the nervous system. Its importance in neuronal apoptosis is well documented. However, the mechanisms involving the regulation of p75NTR in synaptic plasticity and cognitive function remain obscure, although cognitive impairment has been associated with a higher expression of p75NTR in neurons. In this review, we discuss the current understanding of how neurons are influenced by p75NTR function to maintain normal neuronal synaptic strength and connectivity, particularly to support learning and memory in the hippocampus. We then discuss the age-associated alterations in neurophysiological mechanisms of synaptic plasticity and cognitive function. Furthermore, we also describe current evidence that has begun to elucidate how p75NTR regulates synaptic changes in aging and age-related neurodegenerative diseases, focusing on the hippocampus. Elucidating the role that p75NTR signaling plays in regulating synaptic plasticity will contribute to a better understanding of cognitive processes and pathological conditions. This will in turn provide novel approaches to improve therapies for the treatment of neurological diseases in which p75NTR dysfunction has been demonstrated.
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18
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Raghuraman R, Manakkadan A, Richter-Levin G, Sajikumar S. Inhibitory Metaplasticity in Juvenile Stressed Rats Restores Associative Memory in Adulthood by Regulating Epigenetic Complex G9a/GLP. Int J Neuropsychopharmacol 2022; 25:576-589. [PMID: 35089327 PMCID: PMC9352179 DOI: 10.1093/ijnp/pyac008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 12/23/2021] [Accepted: 01/25/2022] [Indexed: 11/16/2022] Open
Abstract
BACKGROUND Exposure to juvenile stress was found to have long-term effects on the plasticity and quality of associative memory in adulthood, but the underlying mechanisms are still poorly understood. METHODS Three- to four week-old male Wistar rats were subjected to a 3-day juvenile stress paradigm. Their electrophysiological correlates of memory using the adult hippocampal slice were inspected to detect alterations in long-term potentiation and synaptic tagging and capture model of associativity. These cellular alterations were tied in with the behavioral outcome by subjecting the rats to a step-down inhibitory avoidance paradigm to measure strength in their memory. Given the role of epigenetic response in altering plasticity as a repercussion of juvenile stress, we aimed to chart out the possible epigenetic marker and its regulation in the long-term memory mechanisms using quantitative reverse transcription polymerase chain reaction. RESULTS We demonstrate that even long after the elimination of actual stressors, an inhibitory metaplastic state is evident, which promotes synaptic competition over synaptic cooperation and decline in latency of associative memory in the behavioral paradigm despite the exposure to novelty. Mechanistically, juvenile stress led to a heightened expression of the epigenetic marker G9a/GLP complex, which is thus far ascribed to transcriptional silencing and goal-directed behavior. CONCLUSIONS The blockade of the G9a/GLP complex was found to alleviate deficits in long-term plasticity and associative memory during the adulthood of animals exposed to juvenile stress. Our data provide insights on the long-term effects of juvenile stress that involve epigenetic mechanisms, which directly impact long-term plasticity, synaptic tagging and capture, and associative memory.
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Affiliation(s)
- Radha Raghuraman
- Present address (R.R.): Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York, USA; (A.M.): Multidisciplinary Research Unit, Government Medical College Thiruvananthapuram, Kerala, India
| | - Anoop Manakkadan
- Present address (R.R.): Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, New York, USA; (A.M.): Multidisciplinary Research Unit, Government Medical College Thiruvananthapuram, Kerala, India
| | - Gal Richter-Levin
- Sagol department of Neurobiology, Department of Psychology, University of Haifa, Haifa, Israel ,The Integrated Brain and Behavior Research Center (IBBRC), University of Haifa, Haifa, Israel
| | - Sreedharan Sajikumar
- Correspondence: Sreedharan Sajikumar, PhD, Department of Physiology, National University of Singapore, Singapore 117597, Singapore ()
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19
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Navakkode S, Zhai J, Wong YP, Li G, Soong TW. Enhanced long-term potentiation and impaired learning in mice lacking alternative exon 33 of Ca V1.2 calcium channel. Transl Psychiatry 2022; 12:1. [PMID: 35013113 PMCID: PMC8748671 DOI: 10.1038/s41398-021-01683-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2021] [Revised: 08/25/2021] [Accepted: 09/13/2021] [Indexed: 12/14/2022] Open
Abstract
The CACNA1C (calcium voltage-gated channel subunit alpha 1 C) gene that encodes the CaV1.2 channel is a prominent risk gene for neuropsychiatric and neurodegenerative disorders with cognitive and social impairments like schizophrenia, bipolar disorders, depression and autistic spectrum disorders (ASD). We have shown previously that mice with exon 33 deleted from CaV1.2 channel (CaV1.2-exon 33-/-) displayed increased CaV1.2 current density and single channel open probability in cardiomyocytes, and were prone to develop arrhythmia. As Ca2+ entry through CaV1.2 channels activates gene transcription in response to synaptic activity, we were intrigued to explore the possible role of Cav1.2Δ33 channels in synaptic plasticity and behaviour. Homozygous deletion of alternative exon 33 resulted in enhanced long-term potentiation (LTP), and lack of long- term depression (LTD), which did not correlate with enhanced learning. Exon 33 deletion also led to a decrease in social dominance, sociability and social novelty. Our findings shed light on the effect of gain-of-function of CaV1.2Δ33 signalling on synaptic plasticity and behaviour and provides evidence for a link between CaV1.2 and distinct cognitive and social behaviours associated with phenotypic features of psychiatric disorders like schizophrenia, bipolar disorder and ASD.
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Affiliation(s)
- Sheeja Navakkode
- grid.4280.e0000 0001 2180 6431Department of Physiology, National University of Singapore, Singapore, Singapore ,grid.59025.3b0000 0001 2224 0361Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
| | - Jing Zhai
- grid.4280.e0000 0001 2180 6431Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Yuk Peng Wong
- grid.4280.e0000 0001 2180 6431Department of Physiology, National University of Singapore, Singapore, Singapore
| | - Guang Li
- grid.4280.e0000 0001 2180 6431Department of Physiology, National University of Singapore, Singapore, Singapore ,grid.410578.f0000 0001 1114 4286Present Address: Key Laboratory of Medical Electrophysiology, Ministry of Education, Institute of Cardiovascular Research, Southwest Medical University, Luzhou, Sichuan China
| | - Tuck Wah Soong
- Department of Physiology, National University of Singapore, Singapore, Singapore. .,Healthy Longevity Research Programme, Yong Loo Lin School of Medicine, National University of Singapore, Singapore, Singapore.
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20
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Cade S, Zhou XF, Bobrovskaya L. The role of brain-derived neurotrophic factor and the neurotrophin receptor p75NTR in age-related brain atrophy and the transition to Alzheimer's disease. Rev Neurosci 2022; 33:515-529. [PMID: 34982865 DOI: 10.1515/revneuro-2021-0111] [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: 08/24/2021] [Accepted: 12/11/2021] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease is a neurodegenerative condition that is potentially mediated by synaptic dysfunction before the onset of cognitive impairments. The disease mostly affects elderly people and there is currently no therapeutic which halts its progression. One therapeutic strategy for Alzheimer's disease is to regenerate lost synapses by targeting mechanisms involved in synaptic plasticity. This strategy has led to promising drug candidates in clinical trials, but further progress needs to be made. An unresolved problem of Alzheimer's disease is to identify the molecular mechanisms that render the aged brain susceptible to synaptic dysfunction. Understanding this susceptibility may identify drug targets which could halt, or even reverse, the disease's progression. Brain derived neurotrophic factor is a neurotrophin expressed in the brain previously implicated in Alzheimer's disease due to its involvement in synaptic plasticity. Low levels of the protein increase susceptibility to the disease and post-mortem studies consistently show reductions in its expression. A desirable therapeutic approach for Alzheimer's disease is to stimulate the expression of brain derived neurotrophic factor and potentially regenerate lost synapses. However, synthesis and secretion of the protein are regulated by complex activity-dependent mechanisms within neurons, which makes this approach challenging. Moreover, the protein is synthesised as a precursor which exerts the opposite effect of its mature form through the neurotrophin receptor p75NTR. This review will evaluate current evidence on how age-related alterations in the synthesis, processing and signalling of brain derived neurotrophic factor may increase the risk of Alzheimer's disease.
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Affiliation(s)
- Shaun Cade
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia
| | - Xin-Fu Zhou
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia
| | - Larisa Bobrovskaya
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA 5000, Australia
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Trubnikova OA, Tarasova IV, Moskin EG, Kupriyanova DS, Argunova YA, Pomeshkina SA, Gruzdeva OV, Barbarash OL. Beneficial Effects of a Short Course of Physical Prehabilitation on Neurophysiological Functioning and Neurovascular Biomarkers in Patients Undergoing Coronary Artery Bypass Grafting. Front Aging Neurosci 2021; 13:699259. [PMID: 34955803 PMCID: PMC8704127 DOI: 10.3389/fnagi.2021.699259] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2021] [Accepted: 11/16/2021] [Indexed: 11/30/2022] Open
Abstract
This study aimed to evaluate the effects of a short course of physical prehabilitation on neurophysiological functioning and markers of the neurovascular unit in patients undergoing coronary artery bypass grafting (CABG). We performed a prospective randomized study involving 97 male CABG patients aged 45–70 years, 47 of whom underwent a 5–7-day preoperative course of aerobic physical training (PhT). Both groups of patients were comparable with respect to baseline clinical and anamnestic characteristics. An extended neuropsychological and electroencephalographic (EEG) study was performed before surgery and at 7–10 days after CABG. Markers of the neurovascular unit [S100β, neuron-specific enolase (NSE), and brain-derived neurotrophic factor (BDNF)] were examined as metabolic correlations of early postoperative cognitive dysfunction (POCD) at three time points: before surgery, within the first 24 h after surgery, and 7–10 days after CABG. POCD developed in 58% of patients who underwent preoperative PhT, and in 79.5% of patients who did not undergo training, 7–10 days after CABG. Patients without prehabilitation demonstrated a higher percentage of theta1 power increase in the relative change values as compared to the PhT patients (p = 0.015). The short preoperative course of PhT was associated with low plasma S100β concentration, but high BDNF levels in the postoperative period. Patients who underwent a short preoperative course of PhT had better cognitive and electrical cortical activity indicators. Markers of the neurovascular unit indicated lower perioperative brain injury after CABG in those who underwent training. A short course of PhT before CABG can decrease the brain’s susceptibility to ischemia and reduce the severity of cognitive impairments in cardiac surgery patients. Electrical brain activity indicators and neurovascular markers, such as S100β and BDNF, can be informative for the effectiveness of cardiac rehabilitation programs.
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Affiliation(s)
- Olga A Trubnikova
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia
| | - Irina V Tarasova
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia
| | - Evgeniy G Moskin
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia
| | - Darya S Kupriyanova
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia
| | - Yuliya A Argunova
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia
| | | | - Olga V Gruzdeva
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia
| | - Olga L Barbarash
- Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo, Russia
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22
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In vivo functions of p75 NTR: challenges and opportunities for an emerging therapeutic target. Trends Pharmacol Sci 2021; 42:772-788. [PMID: 34334250 DOI: 10.1016/j.tips.2021.06.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 05/31/2021] [Accepted: 06/28/2021] [Indexed: 12/24/2022]
Abstract
The p75 neurotrophin receptor (p75NTR) functions at the molecular nexus of cell death, survival, and differentiation. In addition to its contribution to neurodegenerative diseases and nervous system injuries, recent studies have revealed unanticipated roles of p75NTR in liver repair, fibrinolysis, lung fibrosis, muscle regeneration, and metabolism. Linking these various p75NTR functions more precisely to specific mechanisms marks p75NTR as an emerging candidate for therapeutic intervention in a wide range of disorders. Indeed, small molecule inhibitors of p75NTR binding to neurotrophins have shown efficacy in models of Alzheimer's disease (AD) and neurodegeneration. Here, we outline recent advances in understanding p75NTR pleiotropic functions in vivo, and propose an integrated view of p75NTR and its challenges and opportunities as a pharmacological target.
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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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Brain-Derived Neurotrophic Factor Signaling in the Pathophysiology of Alzheimer's Disease: Beneficial Effects of Flavonoids for Neuroprotection. Int J Mol Sci 2021; 22:ijms22115719. [PMID: 34071978 PMCID: PMC8199014 DOI: 10.3390/ijms22115719] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Revised: 05/21/2021] [Accepted: 05/25/2021] [Indexed: 12/16/2022] Open
Abstract
The function of the brain-derived neurotrophic factor (BDNF) via activation through its high-affinity receptor Tropomyosin receptor kinase B (TrkB) has a pivotal role in cell differentiation, cell survival, synaptic plasticity, and both embryonic and adult neurogenesis in central nervous system neurons. A number of studies have demonstrated the possible involvement of altered expression and action of the BDNF/TrkB signaling in the pathogenesis of neurodegenerative diseases, including Alzheimer’s disease (AD). In this review, we introduce an essential role of the BDNF and its downstream signaling in neural function. We also review the current evidence on the deregulated the BDNF signaling in the pathophysiology of AD at gene, mRNA, and protein levels. Further, we discuss a potential usefulness of small compounds, including flavonoids, which can stimulate BDNF-related signaling as a BDNF-targeting therapy.
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