1
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Geigenmüller JN, Tari AR, Wisloff U, Walker TL. The relationship between adult hippocampal neurogenesis and cognitive impairment in Alzheimer's disease. Alzheimers Dement 2024. [PMID: 39166771 DOI: 10.1002/alz.14179] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2024] [Revised: 07/14/2024] [Accepted: 07/16/2024] [Indexed: 08/23/2024]
Abstract
Neurogenesis persists throughout adulthood in the hippocampus and contributes to specific cognitive functions. In Alzheimer's disease (AD), the hippocampus is affected by pathology and functional impairment early in the disease. Human AD patients have reduced adult hippocampal neurogenesis (AHN) levels compared to age-matched healthy controls. Similarly, rodent AD models show a decrease in AHN before the onset of the classical hallmarks of AD pathology. Conversely, enhancement of AHN can protect against AD pathology and ameliorate memory deficits in both rodents and humans. Therefore, impaired AHN may be a contributing factor of AD-associated cognitive decline, rather than an effect of it. In this review we outline the regulation and function of AHN in healthy individuals, and highlight the relationship between AHN dysfunction and cognitive impairments in AD. The existence of AHN in humans and its relevance in AD patients will also be discussed, with an outlook toward future research directions. HIGHLIGHTS: Adult hippocampal neurogenesis occurs in the brains of mammals including humans. Adult hippocampal neurogenesis is reduced in Alzheimer's disease in humans and animal models.
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Affiliation(s)
| | - Atefe R Tari
- The Cardiac Exercise Research Group at Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
- Department of Neurology and Clinical Neurophysiology, St. Olavs University Hospital, Trondheim University Hospital, Trondheim, Norway
| | - Ulrik Wisloff
- The Cardiac Exercise Research Group at Department of Circulation and Medical Imaging, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - Tara L Walker
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
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2
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Mohd Sahini SN, Mohd Nor Hazalin NA, Srikumar BN, Jayasingh Chellammal HS, Surindar Singh GK. Environmental enrichment improves cognitive function, learning, memory and anxiety-related behaviours in rodent models of dementia: Implications for future study. Neurobiol Learn Mem 2024; 208:107880. [PMID: 38103676 DOI: 10.1016/j.nlm.2023.107880] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 11/27/2023] [Accepted: 12/07/2023] [Indexed: 12/19/2023]
Abstract
Environmental enrichment (EE) is a process of brain stimulation by modifying the surroundings, for example, by changing the sensory, social, or physical conditions. Rodents have been used in such experimental strategies through exposure to diverse physical, social, and exploration conditions. The present study conducted an extensive analysis of the existing literature surrounding the impact of EE on dementia rodent models. The review emphasised the two principal aspects that are very closely related to dementia: cognitive function (learning and memory) as well as psychological factors (anxiety-related behaviours such as phobias and unrealistic worries). Also highlighted were the mechanisms involved in the rodent models of dementia showing EE effects. Two search engines, PubMed and Science Direct, were used for data collection using the following keywords: environmental enrichment, dementia, rodent model, cognitive performance, and anxiety-related behaviour. Fifty-five articles were chosen depending on the criteria for inclusion and exclusion. The rodent models with dementia demonstrated improved learning and memory in the form of hampered inflammatory responses, enhanced neuronal plasticity, and sustained neuronal activity. EE housing also prevented memory impairment through the prevention of amyloid beta (Aβ) seeding formation, an early stage of Aβ plaque formation. The rodents subjected to EE were observed to present increased exploratory activity and exert less anxiety-related behaviour, compared to those in standard housing. However, some studies have proposed that EE intervention through exercise would be too mild to counteract the anxiety-related behaviour and risk assessment behaviour deficits in the Alzheimer's disease rodent model. Future studies should be conducted on old-aged rodents and the duration of EE exposure that would elicit the greatest benefits since the existing studies have been conducted on a range of ages and EE durations. In summary, EE had a considerable effect on dementia rodent models, with the most evident being improved cognitive function.
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Affiliation(s)
- Siti Norhafizah Mohd Sahini
- Department of Pharmaceutical Life Sciences, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Selangor Branch, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia; Outpatient Pharmacy Department, Hospital Raja Permaisuri Bainun, 30450 Ipoh, Perak, Malaysia
| | - Nurul Aqmar Mohd Nor Hazalin
- Department of Pharmaceutical Life Sciences, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Selangor Branch, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia; Integrative Pharmacogenomics Institute (iPROMiSE), Level 7, FF3, Universiti Teknologi MARA, Selangor Branch, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia
| | - Bettadapura N Srikumar
- Department of Neurophysiology, National Institute of Mental Health and Neuro Sciences (NIMHANS), Hosur Road, Bengaluru - 560029, India
| | - Hanish Singh Jayasingh Chellammal
- Department of Pharmacology and Pharmaceutical Chemistry, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Selangor Branch, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia; Brain Degeneration and Therapeutics Group, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia
| | - Gurmeet Kaur Surindar Singh
- Department of Pharmaceutical Life Sciences, Faculty of Pharmacy, Universiti Teknologi MARA (UiTM), Selangor Branch, Puncak Alam Campus, 42300 Bandar Puncak Alam, Selangor, Malaysia; Brain Degeneration and Therapeutics Group, Universiti Teknologi MARA (UiTM), 40450 Shah Alam, Selangor, Malaysia.
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3
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Mishra P, Silva A, Sharma J, Nguyen J, Pizzo DP, Hinz D, Sahoo D, Cherqui S. Rescue of Alzheimer's disease phenotype in a mouse model by transplantation of wild-type hematopoietic stem and progenitor cells. Cell Rep 2023; 42:112956. [PMID: 37561625 PMCID: PMC10617121 DOI: 10.1016/j.celrep.2023.112956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 05/19/2023] [Accepted: 07/22/2023] [Indexed: 08/12/2023] Open
Abstract
Alzheimer's disease (AD) is the most prevalent cause of dementia; microglia have been implicated in AD pathogenesis, but their role is still matter of debate. Our study showed that single systemic wild-type (WT) hematopoietic stem and progenitor cell (HSPC) transplantation rescued the AD phenotype in 5xFAD mice and that transplantation may prevent microglia activation. Indeed, complete prevention of memory loss and neurocognitive impairment and decrease of β-amyloid plaques in the hippocampus and cortex were observed in the WT HSPC-transplanted 5xFAD mice compared with untreated 5xFAD mice and with mice transplanted with 5xFAD HSPCs. Neuroinflammation was also significantly reduced. Transcriptomic analysis revealed a significant decrease in gene expression related to "disease-associated microglia" in the cortex and "neurodegeneration-associated endothelial cells" in the hippocampus of the WT HSPC-transplanted 5xFAD mice compared with diseased controls. This work shows that HSPC transplant has the potential to prevent AD-associated complications and represents a promising therapeutic avenue for this disease.
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Affiliation(s)
- Priyanka Mishra
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Alexander Silva
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Jay Sharma
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Jacqueline Nguyen
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA
| | - Donald P Pizzo
- Department of Pathology, University of California, San Diego, La Jolla, CA, USA
| | - Denise Hinz
- Flow Cytometry Core Facility, La Jolla Institute for Immunology, La Jolla, CA, USA
| | - Debashis Sahoo
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA; Department of Computer Science and Engineering, University of California, La Jolla, La Jolla, CA, USA; Moores Comprehensive Cancer Center, University of California, La Jolla, La Jolla, CA, USA
| | - Stephanie Cherqui
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA.
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4
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Torraville SE, Flynn CM, Kendall TL, Yuan Q. Life Experience Matters: Enrichment and Stress Can Influence the Likelihood of Developing Alzheimer's Disease via Gut Microbiome. Biomedicines 2023; 11:1884. [PMID: 37509523 PMCID: PMC10377385 DOI: 10.3390/biomedicines11071884] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Revised: 06/21/2023] [Accepted: 06/30/2023] [Indexed: 07/30/2023] Open
Abstract
Alzheimer's disease (AD) is a chronic neurodegenerative disease, characterized by the presence of β-amyloid (Aβ) plaques and neurofibrillary tangles (NFTs) formed from abnormally phosphorylated tau proteins (ptau). To date, there is no cure for AD. Earlier therapeutic efforts have focused on the clinical stages of AD. Despite paramount efforts and costs, pharmaceutical interventions including antibody therapies targeting Aβ have largely failed. This highlights the need to alternate treatment strategies and a shift of focus to early pre-clinical stages. Approximately 25-40% of AD cases can be attributed to environmental factors including chronic stress. Gut dysbiosis has been associated with stress and the pathogenesis of AD and can increase both Aβ and NFTs in animal models of the disease. Both stress and enrichment have been shown to alter AD progression and gut health. Targeting stress-induced gut dysbiosis through probiotic supplementation could provide a promising intervention to delay disease progression. In this review, we discuss the effects of stress, enrichment, and gut dysbiosis in AD models and the promising evidence from probiotic intervention studies.
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Affiliation(s)
- Sarah E Torraville
- Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1B 3V6, Canada
| | - Cassandra M Flynn
- Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1B 3V6, Canada
| | - Tori L Kendall
- Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1B 3V6, Canada
| | - Qi Yuan
- Biomedical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, NL A1B 3V6, Canada
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5
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Stazi M, Zampar S, Klafki HW, Meyer T, Wirths O. A Combination of Caffeine Supplementation and Enriched Environment in an Alzheimer's Disease Mouse Model. Int J Mol Sci 2023; 24:ijms24032155. [PMID: 36768476 PMCID: PMC9916825 DOI: 10.3390/ijms24032155] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 01/12/2023] [Accepted: 01/20/2023] [Indexed: 01/25/2023] Open
Abstract
A variety of factors has been associated with healthy brain aging, and epidemiological studies suggest that physical activity and nutritional supplements such as caffeine may reduce the risk of developing dementia and, in particular, Alzheimer's disease (AD) in later life. Caffeine is known to act as a cognitive enhancer but has been also shown to positively affect exercise performance in endurance activities. We have previously observed that chronic oral caffeine supplementation and a treatment paradigm encompassing physical and cognitive stimulation by enriched environment (EE) housing can improve learning and memory performance and ameliorate hippocampal neuron loss in the Tg4-42 mouse model of AD. Here, we investigated whether these effects were synergistic. To that end, previous findings on individual treatments were complemented with unpublished, additional data and analyzed in depth by ANOVA followed by Bonferroni multiple comparison post tests. We further evaluated whether plasma neurofilament light chain levels reflect neuropathological and behavioral changes observed in the experimental groups. While a treatment combining physical activity and caffeine supplementation significantly improved learning and memory function compared to standard-housed vehicle-treated Tg4-42 in tasks such as the Morris water maze, no major additive effect outperforming the effects of the single interventions was observed.
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Affiliation(s)
- Martina Stazi
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, 37075 Göttingen, Germany
| | - Silvia Zampar
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, 37075 Göttingen, Germany
| | - Hans-Wolfgang Klafki
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, 37075 Göttingen, Germany
| | - Thomas Meyer
- Department of Psychosomatic Medicine, University Medical Center (UMG), Georg-August-University, 37075 Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, 37075 Göttingen, Germany
- Correspondence:
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6
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Combined long-term enriched environment and caffeine supplementation improve memory function in C57Bl6 mice. Eur Arch Psychiatry Clin Neurosci 2023; 273:269-281. [PMID: 35676374 PMCID: PMC9958139 DOI: 10.1007/s00406-022-01431-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Accepted: 05/15/2022] [Indexed: 11/03/2022]
Abstract
Regular physical activity has been associated with healthy brain aging, reflected by beneficial effects on cognition and learning and memory. Nutritional supplements such as caffeine have been shown to act as cognitive enhancers and may possess neuroprotective properties. Interestingly, caffeine also improves athletic capabilities and is widely used by athletes because of its performance-enhancing effect, while information on potential additive beneficial effects of physical activity and caffeine on cognitive performance is scarce. In the present study, the effects of caffeine supplementation in combination with prolonged physical and cognitive stimulation in the form of the enriched environment (EE) housing for a duration of 4 months were analyzed. We demonstrate that caffeine supplementation together with prolonged environmental enrichment led to enhanced memory function, resulting in improved recognition and spatial working memory in behavioral paradigms such as the novel object recognition task or the Morris water maze in C57Bl6 wild-type mice. Mice housed under EE conditions showed increased gene expression levels of brain-derived neurotrophic factor (BDNF) in the hippocampus. The present findings underscore the potential impact of continuous physical activity in the prevention of age-related cognitive decline and may offer new options for combinatorial approaches.
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7
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Niikura R, Miyazaki T, Takase K, Sasaguri H, Saito T, Saido TC, Goto T. Assessments of prolonged effects of desflurane and sevoflurane on motor learning deficits in aged App NL-G-F/NL-G-F mice. Mol Brain 2022; 15:32. [PMID: 35387663 PMCID: PMC8988377 DOI: 10.1186/s13041-022-00910-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2020] [Accepted: 03/16/2022] [Indexed: 11/10/2022] Open
Abstract
As the proportion of elderly in society increases, so do the number of older patients undergoing surgical procedures. This is concerning as exposure to anesthesia has been identified as a risk factor for Alzheimer's disease (AD). However, the causal relationship between clinical AD development and anesthesia remains conjectural. Preclinical studies have demonstrated that anesthesia, such as halothane, isoflurane, and sevoflurane, induces AD-like pathophysiological changes and cognitive impairments in transgenic mouse models of AD. Desflurane does not have these effects and is expected to have more potential for use in elderly patients, yet little is known about its effects, especially on non-cognitive functions, such as motor and emotional functions. Thus, we examined the postanesthetic effects of desflurane and sevoflurane on motor and emotional function in aged AppNL-G-F/NL-G-F (App-KI) mice. This is a recently developed transgenic mouse model of AD exhibiting amyloid β peptide (Aβ) amyloidosis and a neuroinflammatory response in an age-dependent manner without non-physiological amyloid precursor protein (APP) overexpression. Mice were subjected to a short behavioral test battery consisting of an elevated plus maze, a balance beam test, and a tail suspension test seven days after exposure to 8.0% desflurane for 6 h or 2.8% sevoflurane for 2 h. App-KI mice showed significant increments in the percentage of entry and time spent in open arms in the elevated plus maze, increments in the number of slips and latency to traverse for the balance beam test, increments in the limb clasping score, increments in immobile duration, and decrements in latency to first immobile episode for the tail suspension test compared to age-matched wild type (WT) controls. Desflurane- and sevoflurane-exposed App-KI mice showed a delayed decrement in the number of slips for each trial in the balance beam test, while air-treated App-KI mice rapidly improved their performance, and increased their clasping behavior in the tail suspension test. Furthermore, App-KI inhibited the change in membrane GluA3 following exposure to anesthetics in the cerebellum. These results suggest high validity of App-KI mice as an animal model of AD.
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Affiliation(s)
- Ryo Niikura
- Department of Anesthesiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
| | - Tomoyuki Miyazaki
- Department of Anesthesiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan. .,Department of Physiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan.
| | - Kenkichi Takase
- Laboratory of Psychology, Jichi Medical University School of Medicine, Simotsuke, Tochigi, Japan.
| | - Hiroki Sasaguri
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Takashi Saito
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama, Japan.,Department of Neurocognitive Science, Nagoya City University Graduate School of Medical Sciences, Nagoya, Aichi, Japan
| | - Takaomi C Saido
- Laboratory for Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Takahisa Goto
- Department of Anesthesiology, Yokohama City University Graduate School of Medicine, Yokohama, Japan
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8
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Adult Hippocampal Neurogenesis in Alzheimer’s Disease: An Overview of Human and Animal Studies with Implications for Therapeutic Perspectives Aimed at Memory Recovery. Neural Plast 2022; 2022:9959044. [PMID: 35075360 PMCID: PMC8783751 DOI: 10.1155/2022/9959044] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Revised: 10/21/2021] [Accepted: 12/15/2021] [Indexed: 12/31/2022] Open
Abstract
The mammalian hippocampal dentate gyrus is a niche for adult neurogenesis from neural stem cells. Newborn neurons integrate into existing neuronal networks, where they play a key role in hippocampal functions, including learning and memory. In the ageing brain, neurogenic capability progressively declines while in parallel increases the risk for developing Alzheimer's disease (AD), the main neurodegenerative disorder associated with memory loss. Numerous studies have investigated whether impaired adult neurogenesis contributes to memory decline in AD. Here, we review the literature on adult hippocampal neurogenesis (AHN) and AD by focusing on both human and mouse model studies. First, we describe key steps of AHN, report recent evidence of this phenomenon in humans, and describe the specific contribution of newborn neurons to memory, as evinced by animal studies. Next, we review articles investigating AHN in AD patients and critically examine the discrepancies among different studies over the last two decades. Also, we summarize researches investigating AHN in AD mouse models, and from these studies, we extrapolate the contribution of molecular factors linking AD-related changes to impaired neurogenesis. Lastly, we examine animal studies that link impaired neurogenesis to specific memory dysfunctions in AD and review treatments that have the potential to rescue memory capacities in AD by stimulating AHN.
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9
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Zhang Y, Warden AR, Ahmad KZ, Liu Y, He X, Zheng M, Huo X, Zhi X, Ke Y, Li H, Yan S, Su W, Cai D, Ding X. Single-Cell Microwell Platform Reveals Circulating Neural Cells as a Clinical Indicator for Patients with Blood-Brain Barrier Breakdown. RESEARCH 2021; 2021:9873545. [PMID: 34327332 PMCID: PMC8285994 DOI: 10.34133/2021/9873545] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 06/01/2021] [Indexed: 12/21/2022]
Abstract
Central nervous system diseases commonly occur with the destruction of the blood-brain barrier. As a primary cause of morbidity and mortality, stroke remains unpredictable and lacks cellular biomarkers that accurately quantify its occurrence and development. Here, we identify NeuN+/CD45−/DAPI+ phenotype nonblood cells in the peripheral blood of mice subjected to middle cerebral artery occlusion (MCAO) and stroke patients. Since NeuN is a specific marker of neural cells, we term these newly identified cells as circulating neural cells (CNCs). We find that the enumeration of CNCs in the blood is significantly associated with the severity of brain damage in MCAO mice (p < 0.05). Meanwhile, the number of CNCs is significantly higher in stroke patients than in negative subjects (p < 0.0001). These findings suggest that the amount of CNCs in circulation may serve as a clinical indicator for the real-time prognosis and progression monitor of the occurrence and development of ischemic stroke and other nervous system disease.
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Affiliation(s)
- Yu Zhang
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Antony R Warden
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Khan Zara Ahmad
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Yanlei Liu
- Shanghai Engineering Research Centre for Intelligent Diagnosis and Treatment Instrument, Department of Instrument Science and Engineering, School of Electronic Information and Electrical Engineering, Shanghai Jiao Tong University, 800 Dongchuan Road, Shanghai 200240, China
| | - Xijun He
- Department of Neurosurgery, Wenling Hospital Affiliated to Wenzhou Medical University, Chuan'an Nan Road, Chengxi Subdistrict, Wenling, 317500 Zhejiang, China
| | - Minqiao Zheng
- Central Laboratory, Wenling Hospital Affiliated to Wenzhou Medical University, Chuan'an Nan Road, Chengxi Subdistrict, Wenling, 317500 Zhejiang, China
| | - Xinlong Huo
- Department of Neurology, Wenling Hospital Affiliated to Wenzhou Medical University, Chuan'an Nan Road, Chengxi Subdistrict, Wenling, 317500 Zhejiang, China
| | - Xiao Zhi
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Yuqing Ke
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Hongxia Li
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Sijia Yan
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Wenqiong Su
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
| | - Deng Cai
- Department of Thoracic Surgery, Shanghai Chest Hospital, Shanghai Jiao Tong University, 241 West Huaihai Road, Shanghai 200030, China
| | - Xianting Ding
- State Key Laboratory of Oncogenes and Related Genes, Institute for Personalized Medicine, School of Biomedical Engineering, Shanghai Jiao Tong University, 1954 Huashan Road, Shanghai 200030, China
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10
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Stozicka Z, Korenova M, Uhrinova I, Cubinkova V, Cente M, Kovacech B, Babindakova N, Matyasova K, Vargova G, Novak M, Novak P, Zilka N, Jadhav S. Environmental Enrichment Rescues Functional Deficit and Alters Neuroinflammation in a Transgenic Model of Tauopathy. J Alzheimers Dis 2021; 74:951-964. [PMID: 32116255 DOI: 10.3233/jad-191112] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Alzheimer's disease (AD) is the most frequent neurodegenerative disorder, affecting over 44 million people worldwide. There are no effective pharmaco-therapeutic options for prevention and treatment of AD. Non-pharmacological approaches may help patients suffering from AD to significantly ameliorate disease progression. In this study, we exposed a transgenic rat model (tg) of human tauopathy to enriched environment for 3 months. Behavioral testing at 6 months of age revealed improvement in functional deficits of tg rats reared under enriched conditions, while sedentary tg rats remained severely impaired. Interestingly, enriched environment did not reduce tau pathology. Analysis of neurotrophic factors revealed an increase of nerve growth factor (NGF) levels in the hippocampus of both enriched groups (tg and non-tg rats), reflecting a known effect of enriched environment on the hippocampal formation. On the contrary, NGF levels decreased markedly in the brainstem of enriched groups. The non-pharmacological treatment also reduced levels of tissue inhibitor of metalloproteinase 1 in the brainstem of transgenic rats. Expression analysis of inflammatory pathways revealed upregulation of microglial markers, such as MHC class II and Cd74, whereas levels of pro-inflammatory cytokines remained unaffected by enriched environment. Our results demonstrate that exposure to enriched environment can rescue functional impairment in tau transgenic rats without reducing tau pathology. We speculate that non-pharmacological treatment modulates the immune response to pathological tau protein inclusions, and thus reduces the damage caused by neuroinflammation.
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Affiliation(s)
- Zuzana Stozicka
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Miroslava Korenova
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Ivana Uhrinova
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Veronika Cubinkova
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Martin Cente
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Branislav Kovacech
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia.,Axon Neuroscience R&D Services SE, Bratislava, Slovakia
| | - Nikoleta Babindakova
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Katarina Matyasova
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Greta Vargova
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia
| | - Michal Novak
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia.,Axon Neuroscience SE, Larnaca, Cyprus
| | - Petr Novak
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia.,Axon Neuroscience CRM Services SE, Bratislava, Slovakia
| | - Norbert Zilka
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia.,Axon Neuroscience R&D Services SE, Bratislava, Slovakia
| | - Santosh Jadhav
- Institute of Neuroimmunology, Slovak Academy of Sciences, AD Centre, Bratislava, Slovakia.,Axon Neuroscience R&D Services SE, Bratislava, Slovakia
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11
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Babcock KR, Page JS, Fallon JR, Webb AE. Adult Hippocampal Neurogenesis in Aging and Alzheimer's Disease. Stem Cell Reports 2021; 16:681-693. [PMID: 33636114 PMCID: PMC8072031 DOI: 10.1016/j.stemcr.2021.01.019] [Citation(s) in RCA: 124] [Impact Index Per Article: 41.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/27/2021] [Accepted: 01/27/2021] [Indexed: 12/19/2022] Open
Abstract
Cognitive deficits associated with Alzheimer's disease (AD) severely impact daily life for the millions of affected individuals. Progressive memory impairment in AD patients is associated with degeneration of the hippocampus. The dentate gyrus of the hippocampus, a region critical for learning and memory functions, is a site of adult neurogenesis in mammals. Recent evidence in humans indicates that hippocampal neurogenesis likely persists throughout life, but declines with age and is strikingly impaired in AD. Our understanding of how neurogenesis supports learning and memory in healthy adults is only beginning to emerge. The extent to which decreased neurogenesis contributes to cognitive decline in aging and AD remains poorly understood. However, studies in rodent models of AD and other neurodegenerative diseases raise the possibility that targeting neurogenesis may ameliorate cognitive dysfunction in AD. Here, we review recent progress in understanding how adult neurogenesis is impacted in the context of aging and AD.
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Affiliation(s)
- Kelsey R Babcock
- Graduate Program in Neuroscience, Brown University, Providence, RI 02912, USA
| | - John S Page
- Warren Alpert Medical School of Brown University, Providence, RI 02912, USA; Department of Neuroscience, Brown University, Providence, RI 02912, USA
| | - Justin R Fallon
- Department of Neuroscience, Brown University, Providence, RI 02912, USA; Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Brown University, Providence, RI 02912, USA
| | - Ashley E Webb
- Carney Institute for Brain Science, Brown University, Providence, RI 02912, USA; Center for Translational Neuroscience, Brown University, Providence, RI 02912, USA; Department of Molecular Biology, Cell Biology, and Biochemistry, Brown University, Providence, RI 02912, USA; Center on the Biology of Aging, Brown University, Providence, RI 02912, USA.
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12
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Slomianka L. Basic quantitative morphological methods applied to the central nervous system. J Comp Neurol 2021; 529:694-756. [PMID: 32639600 PMCID: PMC7818269 DOI: 10.1002/cne.24976] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Revised: 06/15/2020] [Accepted: 06/16/2020] [Indexed: 12/19/2022]
Abstract
Generating numbers has become an almost inevitable task associated with studies of the morphology of the nervous system. Numbers serve a desire for clarity and objectivity in the presentation of results and are a prerequisite for the statistical evaluation of experimental outcomes. Clarity, objectivity, and statistics make demands on the quality of the numbers that are not met by many methods. This review provides a refresher of problems associated with generating numbers that describe the nervous system in terms of the volumes, surfaces, lengths, and numbers of its components. An important aim is to provide comprehensible descriptions of the methods that address these problems. Collectively known as design-based stereology, these methods share two features critical to their application. First, they are firmly based in mathematics and its proofs. Second and critically underemphasized, an understanding of their mathematical background is not necessary for their informed and productive application. Understanding and applying estimators of volume, surface, length or number does not require more of an organizational mastermind than an immunohistochemical protocol. And when it comes to calculations, square roots are the gravest challenges to overcome. Sampling strategies that are combined with stereological probes are efficient and allow a rational assessment if the numbers that have been generated are "good enough." Much may be unfamiliar, but very little is difficult. These methods can no longer be scapegoats for discrepant results but faithfully produce numbers on the material that is assessed. They also faithfully reflect problems that associated with the histological material and the anatomically informed decisions needed to generate numbers that are not only valid in theory. It is within reach to generate practically useful numbers that must integrate with qualitative knowledge to understand the function of neural systems.
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Affiliation(s)
- Lutz Slomianka
- University of Zürich, Institute of AnatomyZürichSwitzerland
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13
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Effect of Pleomorphic Adenoma Gene 1 Deficiency on Selected Behaviours in Adult Mice. Neuroscience 2020; 455:30-38. [PMID: 33346119 DOI: 10.1016/j.neuroscience.2020.12.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Revised: 12/03/2020] [Accepted: 12/05/2020] [Indexed: 12/16/2022]
Abstract
The proto-oncogene pleomorphic adenoma gene 1 (Plag1) encodes a zinc finger transcription factor. PLAG1 is part of the high motility group AT hook-2 (HGMA2)-PLAG1-insulin-like growth factor 2 (IGF2) pathway that, when disrupted, leads to Silver-Russell syndrome, a severe form of intrauterine growth restriction. With little known about PLAG1's role in normal physiology, this study is the first to characterise the behavioural phenotype of PLAG1-deficient mice. Mice were tested for differences in circadian locomotor activity and body temperature, sleep-like behaviour, anxiety-like behaviour, cognition, social behaviour, and sensorimotor gating. Overall, the behavioural phenotype of the Plag1 knock-out (KO) mice was mild: no significant differences were seen in circadian activity levels, locomotion, object recognition, spatial memory or sociability compared to wild-type mice. However, the cued test of fear conditioning, prepulse inhibition of the startle response and Preyer's reflex test suggest that Plag1 KO mice may have a hearing impairment. This implies that PLAG1 plays an important role in proper functioning and/or development of the neural circuitry behind the auditory processes or interacts with genes involved in those processes.
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14
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Pritchett-Corning KR. Environmental Complexity and Research Outcomes. ILAR J 2020; 60:239-251. [PMID: 32559304 DOI: 10.1093/ilar/ilaa007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 01/28/2020] [Accepted: 02/04/2020] [Indexed: 11/14/2022] Open
Abstract
Environmental complexity is an experimental paradigm as well as a potential part of animals' everyday housing experiences. In experimental uses, researchers add complexity to stimulate brain development, delay degenerative brain changes, elicit more naturalistic behaviors, and test learning and memory. Complexity can exacerbate or mitigate behavioral problems, give animals a sense of control, and allow for expression of highly driven, species-typical behaviors that can improve animal welfare. Complex environments should be designed thoughtfully with the animal's natural behaviors in mind, reported faithfully in the literature, and evaluated carefully for unexpected effects.
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Affiliation(s)
- Kathleen R Pritchett-Corning
- Office of Animal Resources, Faculty of Arts and Sciences, Harvard University, Cambridge, Massachusetts.,Department of Comparative Medicine, University of Washington, Seattle, Washington
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15
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Stazi M, Wirths O. Physical activity and cognitive stimulation ameliorate learning and motor deficits in a transgenic mouse model of Alzheimer's disease. Behav Brain Res 2020; 397:112951. [PMID: 33027669 DOI: 10.1016/j.bbr.2020.112951] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Revised: 09/07/2020] [Accepted: 09/26/2020] [Indexed: 10/23/2022]
Abstract
Epidemiological studies suggest that physical exercise or cognitive stimulation might contribute to lower the risk of developing dementia disorders such as Alzheimer's disease (AD). Here, we used the well-established enrichment environment (EE) paradigm to study the impact of prolonged physical activity and cognitive stimulation in a mouse model of AD overexpressing only Aβ4-42 peptides. These mice display age-dependent memory and motor deficits, in the absence of human amyloid precursor protein (APP) overexpression. We demonstrate that housing under EE conditions leads to an entire preservation of recognition and spatial memory, as well as a rescue of motor deficits in this mouse model. Moreover, we find that Tg4-42hom mice present a typical floating phenotype in the Morris water maze task that could be completely ameliorated upon long-term EE housing. Our findings are in line with epidemiological studies suggesting that physical activity and cognitive stimulation might represent efficient strategies to prevent age-related neurodegenerative disorders such as AD.
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Affiliation(s)
- Martina Stazi
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, Göttingen, Germany.
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16
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Belaya I, Ivanova M, Sorvari A, Ilicic M, Loppi S, Koivisto H, Varricchio A, Tikkanen H, Walker FR, Atalay M, Malm T, Grubman A, Tanila H, Kanninen KM. Astrocyte remodeling in the beneficial effects of long-term voluntary exercise in Alzheimer's disease. J Neuroinflammation 2020; 17:271. [PMID: 32933545 PMCID: PMC7493971 DOI: 10.1186/s12974-020-01935-w] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Accepted: 08/19/2020] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND Increased physical exercise improves cognitive function and reduces pathology associated with Alzheimer's disease (AD). However, the mechanisms underlying the beneficial effects of exercise in AD on the level of specific brain cell types remain poorly investigated. The involvement of astrocytes in AD pathology is widely described, but their exact role in exercise-mediated neuroprotection warrant further investigation. Here, we investigated the effect of long-term voluntary physical exercise on the modulation of the astrocyte state. METHODS Male 5xFAD mice and their wild-type littermates had free access to a running wheel from 1.5 to 7 months of age. A battery of behavioral tests was used to assess the effects of voluntary exercise on cognition and learning. Neuronal loss, impairment in neurogenesis, beta-amyloid (Aβ) deposition, and inflammation were evaluated using a variety of histological and biochemical measurements. Sophisticated morphological analyses were performed to delineate the specific involvement of astrocytes in exercise-induced neuroprotection in the 5xFAD mice. RESULTS Long-term voluntary physical exercise reversed cognitive impairment in 7-month-old 5xFAD mice without affecting neurogenesis, neuronal loss, Aβ plaque deposition, or microglia activation. Exercise increased glial fibrillary acid protein (GFAP) immunoreactivity and the number of GFAP-positive astrocytes in 5xFAD hippocampi. GFAP-positive astrocytes in hippocampi of the exercised 5xFAD mice displayed increases in the numbers of primary branches and in the soma area. In general, astrocytes distant from Aβ plaques were smaller in size and possessed simplified processes in comparison to plaque-associated GFAP-positive astrocytes. Morphological alterations of GFAP-positive astrocytes occurred concomitantly with increased astrocytic brain-derived neurotrophic factor (BDNF) and restoration of postsynaptic protein PSD-95. CONCLUSIONS Voluntary physical exercise modulates the reactive astrocyte state, which could be linked via astrocytic BDNF and PSD-95 to improved cognition in 5xFAD hippocampi. The molecular pathways involved in this modulation could potentially be targeted for benefit against AD.
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Affiliation(s)
- Irina Belaya
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Mariia Ivanova
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Annika Sorvari
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Marina Ilicic
- School of Biomedical Sciences and Pharmacy and the Priority Research Centre for Stroke and Brain Injury, The University of Newcastle, University Dr, Callaghan, NSW, 2308, Australia
| | - Sanna Loppi
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Hennariikka Koivisto
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Alessandra Varricchio
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Heikki Tikkanen
- Institute of Biomedicine, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Frederick R Walker
- School of Biomedical Sciences and Pharmacy and the Priority Research Centre for Stroke and Brain Injury, The University of Newcastle, University Dr, Callaghan, NSW, 2308, Australia
| | - Mustafa Atalay
- Institute of Biomedicine, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Tarja Malm
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Alexandra Grubman
- Department of Anatomy and Developmental Biology, Monash University, Melbourne, Australia
- Development and Stem Cells Program, Monash Biomedicine Discovery Institute, Melbourne, Australia
- Australian Regenerative Medicine Institute, Monash University, Melbourne, Australia
| | - Heikki Tanila
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland
| | - Katja M Kanninen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, FI-70211, Kuopio, Finland.
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17
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Stazi M, Wirths O. Chronic Memantine Treatment Ameliorates Behavioral Deficits, Neuron Loss, and Impaired Neurogenesis in a Model of Alzheimer's Disease. Mol Neurobiol 2020; 58:204-216. [PMID: 32914393 PMCID: PMC7695672 DOI: 10.1007/s12035-020-02120-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2020] [Accepted: 09/05/2020] [Indexed: 02/06/2023]
Abstract
Memantine, a non-competitive NMDA receptor antagonist possessing neuroprotective properties, belongs to the small group of drugs which have been approved for the treatment of Alzheimer's disease (AD). While several preclinical studies employing different transgenic AD mouse models have described beneficial effects with regard to rescued behavioral deficits or reduced amyloid plaque pathology, it is largely unknown whether memantine might have beneficial effects on neurodegeneration. In the current study, we assessed whether memantine treatment has an impact on hippocampal neuron loss and associated behavioral deficits in the Tg4-42 mouse model of AD. We demonstrate that a chronic oral memantine treatment for 4 months diminishes hippocampal CA1 neuron loss and rescues learning and memory performance in different behavioral paradigms, such as Morris water maze or a novel object recognition task. Cognitive benefits of chronic memantine treatment were accompanied by an amelioration of impaired adult hippocampal neurogenesis. Taken together, our results demonstrate that memantine successfully counteracts pathological alterations in a preclinical mouse model of AD.
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Affiliation(s)
- Martina Stazi
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August University, Von-Siebold-Str. 5, 37075, Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August University, Von-Siebold-Str. 5, 37075, Göttingen, Germany.
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18
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Gerberding AL, Zampar S, Stazi M, Liebetanz D, Wirths O. Physical Activity Ameliorates Impaired Hippocampal Neurogenesis in the Tg4-42 Mouse Model of Alzheimer's Disease. ASN Neuro 2020; 11:1759091419892692. [PMID: 31818124 PMCID: PMC6906584 DOI: 10.1177/1759091419892692] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
There is growing evidence from epidemiological studies that especially midlife physical activity might exert a positive influence on the risk and progression of Alzheimer’s disease. In this study, the Tg4-42 mouse model of Alzheimer’s disease has been utilized to assess the effect of different housing conditions on structural changes in the hippocampus. Focusing on the dentate gyrus, we demonstrate that 6-month-old Tg4-42 mice have a reduced number of newborn neurons in comparison to age-matched wild-type mice. Housing these mice for 4 months with either unlimited or intermittent access to a running wheel resulted in a significant rescue of dentate gyrus neurogenesis. Although neither dentate gyrus volume nor neuron number could be modified in this Alzheimer’s disease mouse model, unrestricted access to a running wheel significantly increased dentate gyrus volume and granule cell number in wild-type mice.
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Affiliation(s)
- Anna-Lina Gerberding
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - Silvia Zampar
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - Martina Stazi
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - David Liebetanz
- Department of Clinical Neurophysiology, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
| | - Oliver Wirths
- Department of Psychiatry and Psychotherapy, Molecular Psychiatry, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
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19
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20
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Khacho M, Harris R, Slack RS. Mitochondria as central regulators of neural stem cell fate and cognitive function. Nat Rev Neurosci 2019; 20:34-48. [PMID: 30464208 DOI: 10.1038/s41583-018-0091-3] [Citation(s) in RCA: 217] [Impact Index Per Article: 43.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Emerging evidence now indicates that mitochondria are central regulators of neural stem cell (NSC) fate decisions and are crucial for both neurodevelopment and adult neurogenesis, which in turn contribute to cognitive processes in the mature brain. Inherited mutations and accumulated damage to mitochondria over the course of ageing serve as key factors underlying cognitive defects in neurodevelopmental disorders and neurodegenerative diseases, respectively. In this Review, we explore the recent findings that implicate mitochondria as crucial regulators of NSC function and cognition. In this respect, mitochondria may serve as targets for stem-cell-based therapies and interventions for cognitive defects.
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Affiliation(s)
- Mireille Khacho
- Department of Biochemistry, Microbiology and Immunology, Ottawa Institute of Systems Biology (OISB), University of Ottawa, Ottawa, Ontario, Canada
| | - Richard Harris
- Department of Cellular and Molecular Medicine, University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
| | - Ruth S Slack
- Department of Cellular and Molecular Medicine, University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada.
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21
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Serra L, Gelfo F, Petrosini L, Di Domenico C, Bozzali M, Caltagirone C. Rethinking the Reserve with a Translational Approach: Novel Ideas on the Construct and the Interventions. J Alzheimers Dis 2019; 65:1065-1078. [PMID: 30149458 DOI: 10.3233/jad-180609] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The concept of brain, cognitive, and neural reserves has been introduced to account for the apparent discrepancies between neurological damage and clinical manifestations. However, these ideas are yet theoretical suggestions that are not completely assimilated in the clinical routine. The mechanisms of the reserves have been extensively studied in neurodegenerative pathologies, in particular in Alzheimer's disease. Both human and animal studies addressed this topic by following two parallel pathways. The specific aim of the present review is to attempt to combine the suggestions derived from the two different research fields to deepen the knowledge about reserves. In fact, the achievement of a comprehensive theoretical framework on reserve mechanisms is an essential step to propose well-timed interventions tailored to the clinical characteristics of patients. The present review highlights the importance of addressing three main aspects: the definition of reserve proxy measures, the interaction between reserve level and therapeutic interventions, and the specific time-window of reserve efficacy.
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Affiliation(s)
- Laura Serra
- Neuroimaging Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy
| | - Francesca Gelfo
- Department of Clinical and Behavioural Neurology, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Human Sciences, Guglielmo Marconi University, Rome, Italy
| | - Laura Petrosini
- Laboratory of Experimental Neurophysiology and Behaviour, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Psychology, University Sapienza of Rome, Rome, Italy
| | | | - Marco Bozzali
- Neuroimaging Laboratory, IRCCS Fondazione Santa Lucia, Rome, Italy.,Clinical Imaging Science Center, Brighton and Sussex Medical School, Brighton, UK
| | - Carlo Caltagirone
- Department of Clinical and Behavioural Neurology, IRCCS Fondazione Santa Lucia, Rome, Italy.,Department of Systemic Medicine, University of Rome Tor Vergata, Rome, Italy
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22
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Wang H, Li Q, Tang H, Ding J, Xu N, Sun S, Chen S. The activated newborn neurons participate in enriched environment induced improvement of locomotor function in APP/PS1 mice. Brain Behav 2019; 9:e01316. [PMID: 31094092 PMCID: PMC6625533 DOI: 10.1002/brb3.1316] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 04/29/2019] [Accepted: 04/29/2019] [Indexed: 11/06/2022] Open
Abstract
INTRODUCTION Alzheimer's disease (AD) is an age-related neurodegenerative disorder. One of the pathological features of AD is neuronal loss in brain regions associated with cognition, particularly the hippocampus. An enriched environment (EE) can facilitate neuronal plasticity and improve behaviors such as emotion, motor function, and cognition in AD. METHODS After APP/PS1 mice were exposed to EE at an early stage (2 months of age), elevated plus maze performance and contextual fear conditioning were tested, and neurogenesis and the extent of activation in the hippocampus were observed. RESULTS The results showed that, compared with that in the mice that experienced a standard environment, the cognition of the mice exposed to EE, as measured by contextual fear conditioning, was not statistically significant. However, based on their performance in the elevated plus maze, the index was increased in the mice, especially the APP/PS1 mice, exposed to EE. Consistent with the behavioral changes, the APP/PS1 mice exposed to EE showed an increased number of c-Fos-positive neurons and elevated neurogenesis in the dentate gyrus (DG) area. In addition, the activation of newborn neurons did not occur in the other three groups. CONCLUSIONS These results indicate that the activation of newborn neurons may participate in the improvement of behavioral performance in APP/PS1 mice after EE.
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Affiliation(s)
- Hualong Wang
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Qiongqiong Li
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Huidong Tang
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jianqing Ding
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Nanjie Xu
- Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Suya Sun
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Shengdi Chen
- Department of Neurology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai, China
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23
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Stuart KE, King AE, King NE, Collins JM, Vickers JC, Ziebell JM. Late-life environmental enrichment preserves short-term memory and may attenuate microglia in male APP/PS1 mice. Neuroscience 2019; 408:282-292. [PMID: 30999032 DOI: 10.1016/j.neuroscience.2019.04.015] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 04/04/2019] [Accepted: 04/05/2019] [Indexed: 02/08/2023]
Abstract
Environmental enrichment (EE) has been consistently reported to enhance cognitive function in mouse models of neuropathology. Microglia, implicated in Alzheimer's disease pathology, may mediate this effect. The aim of the present study was to investigate the effect of EE on cognitive function and microglia in mouse models of aging and amyloidosis. Male wild-type (Wt) and APP/PS1 mice were randomly assigned to standard housing (SH) or EE from 12 to 18 months of age. Spatial memory testing was performed using the Y and Barnes maze. Immunohistochemical analysis of Aβ load, Iba1 and CD-68-labeled (phagocytic-type) microglia was examined between conditions. EE from 12 months of age was associated with improved short-term memory performance in APP/PS1 mice, despite no reductions to Aβ load. APP/PS1 mice in SH had significantly increased microglia occupying the neocortex and hippocampus (p = 0.02; p = 0.004, respectively) relative to Wt animals. Microglia labeling was not statistically different between EE-exposed APP/PS1 compared to Wt mice, indicating that EE may attenuate the increased microglial load in aging APP/PS1 mice. APP/PS1 mice from EE had significantly (p = 0.01) higher colocalization of Iba1 and CD-68 labeling, indicative of increased phagocytic microglia compared to mice from SH. The findings of the present study suggest that EE after substantial brain amyloidosis, has the potential to preserve domains of cognitive function, while having no effect on Aβ deposition. The current study demonstrates that EE may attenuate microglia in aging APP/PS1 mice, and may promote alterations in cellular phenotype.
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Affiliation(s)
- Kimberley E Stuart
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia.
| | - Anna E King
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Natalie E King
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Jessica M Collins
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - James C Vickers
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Jenna M Ziebell
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
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24
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Liu E, Zhou Q, Xie AJ, Li M, Zhang S, Huang H, Liuyang Z, Wang Y, Liu B, Li X, Sun D, Wei Y, Wang X, Wang Q, Ke D, Yang X, Yang Y, Wang JZ. Enriched gestation activates the IGF pathway to evoke embryo-adult benefits to prevent Alzheimer's disease. Transl Neurodegener 2019; 8:8. [PMID: 30867903 PMCID: PMC6399936 DOI: 10.1186/s40035-019-0149-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2018] [Accepted: 02/15/2019] [Indexed: 12/13/2022] Open
Abstract
Background Building brain reserves before dementia onset could represent a promising strategy to prevent Alzheimer's disease (AD), while how to initiate early cognitive stimulation is unclear. Given that the immature brain is more sensitive to environmental stimuli and that brain dynamics decrease with ageing, we reasoned that it would be effective to initiate cognitive stimulation against AD as early as the fetal period. Methods After conception, maternal AD transgenic mice (3 × Tg AD) were exposed to gestational environment enrichment (GEE) until the day of delivery. The cognitive capacity of the offspring was assessed by the Morris water maze and contextual fear-conditioning tests when the offspring were raised in a standard environment to 7 months of age. Western blotting, immunohistochemistry, real-time PCR, immunoprecipitation, chromatin immunoprecipitation (ChIP) assay, electrophysiology, Golgi staining, activity assays and sandwich ELISA were employed to gain insight into the mechanisms underlying the beneficial effects of GEE on embryos and 7-10-month-old adult offspring. Results We found that GEE markedly preserved synaptic plasticity and memory capacity with amelioration of hallmark pathologies in 7-10-m-old AD offspring. The beneficial effects of GEE were accompanied by global histone hyperacetylation, including those at bdnf promoter-binding regions, with robust BDNF mRNA and protein expression in both embryo and progeny hippocampus. GEE increased insulin-like growth factor 1 (IGF1) and activated its receptor (IGF1R), which phosphorylates Ca2+/calmodulin-dependent kinase IV (CaMKIV) at tyrosine sites and triggers its nuclear translocation, subsequently upregulating histone acetyltransferase (HAT) and BDNF transcription. The upregulation of IGF1 mimicked the effects of GEE, while IGF1R or HAT inhibition during pregnancy abolished the GEE-induced CaMKIV-dependent histone hyperacetylation and BDNF upregulation. Conclusions These findings suggest that activation of IGF1R/CaMKIV/HAT/BDNF signaling by gestational environment enrichment may serve as a promising strategy to delay AD progression.
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Affiliation(s)
- Enjie Liu
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China.,4Department of Pathology, the First Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052 China
| | - Qiuzhi Zhou
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Ao-Ji Xie
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Mengzhu Li
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Shujuan Zhang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Hezhou Huang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Zhenyu Liuyang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Yali Wang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Bingjin Liu
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Xiaoguang Li
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Dongsheng Sun
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Yuping Wei
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Xiaochuan Wang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Qun Wang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Dan Ke
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Xifei Yang
- Key Laboratory of Modern Toxicology of Shenzhen, Shenzhen Centre for Disease Control and Prevention, 8 Longyuan Road, Shenzhen, 518055 China
| | - Ying Yang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China
| | - Jian-Zhi Wang
- 1Department of Pathophysiology, School of Basic Medicine and the Collaborative Innovation Center for Brain Science, Key Laboratory of Ministry of Education of China for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030 China.,2Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226000 China
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25
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Androuin A, Abada YS, Ly M, Santin M, Petiet A, Epelbaum S, Bertrand A, Delatour B. Activity-induced MEMRI cannot detect functional brain anomalies in the APPxPS1-Ki mouse model of Alzheimer's disease. Sci Rep 2019; 9:1140. [PMID: 30718666 PMCID: PMC6361936 DOI: 10.1038/s41598-018-37980-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2018] [Accepted: 12/10/2018] [Indexed: 12/02/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common cause of dementia. Aside neuropathological lesions, abnormal neuronal activity and brain metabolism are part of the core symptoms of the disease. Activity-induced Manganese-Enhanced Magnetic Resonance Imaging (MEMRI) has been proposed as a powerful approach to visualize evoked brain activity in rodents. Here, we evaluated the relevance of MEMRI in measuring neuronal (dys-)function in the APPxPS1 knocked-in (KI) mouse model of AD. Brain anomalies were firstly demonstrated in APPxPS1-Ki mice using cognitive testing (memory impairment) and histological mapping of immediate early gene products (decreased density of fos-positive neurons). Paradoxically, MEMRI analyses were not able to confirm the occurrence of neuronal hypoactivities in vivo. We then performed a neuropathological analysis that highlighted an abnormal increased permeability of the blood-brain barrier (BBB) in APPxPS1-Ki mice. We hypothesized that diffuse weakening of the BBB results in an uncontrolled diffusion of the MR contrast agent and a lack of correlation between manganese accumulation and neuronal activity. These results bring to light a limitation of the activity-induced MEMRI approach when applied to the APPxPS1-Ki mouse model as well as other mouse models harboring a compromised BBB.
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Affiliation(s)
- Alexandre Androuin
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Yah-Se Abada
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France
| | - Myriam Ly
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Institut Roche, Boulogne-Billancourt, France
| | - Mathieu Santin
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Center for Neuroimaging Research, Institut du Cerveau et de la Moelle épinière, Paris, France
| | - Alexandra Petiet
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Center for Neuroimaging Research, Institut du Cerveau et de la Moelle épinière, Paris, France
| | - Stéphane Epelbaum
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Centre des Maladies Cognitives et Comportementales, Sorbonne Universités, Hôpital de la Salpêtrière, Paris, France.,Aramis Project Team, Inria Research Center of Paris, Paris, France
| | - Anne Bertrand
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.,Aramis Project Team, Inria Research Center of Paris, Paris, France
| | - Benoît Delatour
- Institut du Cerveau et de la Moelle épinière, INSERM U1127, CNRS UMR7225, Université Pierre et Marie Curie, Sorbonne Universités, Paris, France.
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26
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Llorens-Martín M. Exercising New Neurons to Vanquish Alzheimer Disease. Brain Plast 2018; 4:111-126. [PMID: 30564550 PMCID: PMC6296267 DOI: 10.3233/bpl-180065] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/21/2018] [Indexed: 02/07/2023] Open
Abstract
Alzheimer disease (AD) is the most common type of dementia in individuals over 65 years of age. The neuropathological hallmarks of the condition are Tau neurofibrillary tangles and Amyloid-β senile plaques. Moreover, certain susceptible regions of the brain experience a generalized lack of neural plasticity and marked synaptic alterations during the progression of this as yet incurable disease. One of these regions, the hippocampus, is characterized by the continuous addition of new neurons throughout life. This phenomenon, named adult hippocampal neurogenesis (AHN), provides a potentially endless source of new synaptic elements that increase the complexity and plasticity of the hippocampal circuitry. Numerous lines of evidence show that physical activity and environmental enrichment (EE) are among the most potent positive regulators of AHN. Given that neural plasticity is markedly decreased in many neurodegenerative diseases, the therapeutic potential of making certain lifestyle changes, such as increasing physical activity, is being recognised in several non-pharmacologic strategies seeking to slow down or prevent the progression of these diseases. This review article summarizes current evidence supporting the putative therapeutic potential of EE and physical exercise to increase AHN and hippocampal plasticity both under physiological and pathological circumstances, with a special emphasis on neurodegenerative diseases and AD.
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Affiliation(s)
- María Llorens-Martín
- Department of Molecular Neuropathology, Centro de Biología Molecular “Severo Ochoa”, CBMSO, CSIC-UAM, Madrid, Spain
- Center for Networked Biomedical Research on Neurodegenerative Diseases CIBERNED, Madrid, Spain
- Department of Molecular Biology, Faculty of Sciences, Universidad Autónoma de Madrid, Madrid, Spain
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27
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Shepherd A, Zhang TD, Zeleznikow-Johnston AM, Hannan AJ, Burrows EL. Transgenic Mouse Models as Tools for Understanding How Increased Cognitive and Physical Stimulation Can Improve Cognition in Alzheimer's Disease. Brain Plast 2018; 4:127-150. [PMID: 30564551 PMCID: PMC6296266 DOI: 10.3233/bpl-180076] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Cognitive decline appears as a core feature of dementia, of which the most prevalent form, Alzheimer's disease (AD) affects more than 45 million people worldwide. There is no cure, and therapeutic options remain limited. A number of modifiable lifestyle factors have been identified that contribute to cognitive decline in dementia. Sedentary lifestyle has emerged as a major modifier and accordingly, boosting mental and physical activity may represent a method to prevent decline in dementia. Beneficial effects of increased physical activity on cognition have been reported in healthy adults, showing potential to harness exercise and cognitive stimulation as a therapy in dementia. 'Brain training' (cognitive stimulation) has also been investigated as an intervention protecting against cognitive decline with normal aging. Consequently, the utility of exercise regimes and/or cognitive stimulation to improve cognition in dementia in clinical populations has been a major area of study. However, these therapies are in their infancy and efficacy is unclear. Investigations utilising animal models, where dose and timing of treatment can be tightly controlled, have provided many mechanistic insights. Genetically engineered mouse models are powerful tools to investigate mechanisms underlying cognitive decline, and also how environmental manipulations can alter both cognitive outcomes and pathology. A myriad of effects following physical activity and housing in enriched environments have been reported in transgenic mice expressing Alzheimer's disease-associated mutations. In this review, we comprehensively evaluate all studies applying environmental enrichment and/or increased physical exercise to transgenic mouse models of Alzheimer's disease. It is unclear whether interventions must be applied before first onset of cognitive deficits to be effective. In order to determine the importance of timing of interventions, we specifically scrutinised studies exposing transgenic mice to exercise and environmental enrichment before and after first report of cognitive impairment. We discuss the strengths and weaknesses of these preclinical studies and suggest approaches for enhancing rigor and using mechanistic insights to inform future therapeutic interventions.
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Affiliation(s)
- Amy Shepherd
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Tracy D Zhang
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Ariel M Zeleznikow-Johnston
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia.,Department of Anatomy and Neuroscience, University of Melbourne, Parkville, VIC, Australia
| | - Emma L Burrows
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, VIC, Australia
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28
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O'Leary TP, Mantolino HM, Stover KR, Brown RE. Age-related deterioration of motor function in male and female 5xFAD mice from 3 to 16 months of age. GENES BRAIN AND BEHAVIOR 2018; 19:e12538. [PMID: 30426678 DOI: 10.1111/gbb.12538] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2018] [Revised: 11/05/2018] [Accepted: 11/06/2018] [Indexed: 12/11/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that leads to age-related cognitive and sensori-motor dysfunction. There is an increased understanding that motor dysfunction contributes to overall AD severity, and a need to ameliorate these impairments. The 5xFAD mouse develops the neuropathology, cognitive and motor impairments observed in AD, and thus may be a valuable animal model to study motor deficits in AD. Therefore, we assessed age-related changes in motor ability of male and female 5xFAD mice from 3 to 16 months of age, using a battery of behavioral tests. At 9-10 months, 5xFAD mice showed reduced body weight, reduced rearing in the open-field and impaired performance on the rotarod compared to wild-type controls. At 12-13 months, 5xFAD mice showed reduced locomotor activity on the open-field, and impaired balance on the balance beam. At 15-16 months, impairments were also seen in grip strength. Although sex differences were observed at specific ages, the development of motor dysfunction was similar in male and female mice. Given the 5xFAD mouse is commonly on a C57BL/6 × SJL hybrid background, a subset of mice may be homozygous recessive for the Dysf im mutant allele, which leads to muscular weakness in SJL mice and may exacerbate motor dysfunction. We found small effects of Dysf im on motor function, suggesting that Dysf im contributes little to motor dysfunction in 5xFAD mice. We conclude that the 5xFAD mouse may be a useful model to study mechanisms that produce motor dysfunction in AD, and to assess the efficacy of therapeutics on ameliorating motor impairment.
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Affiliation(s)
- Timothy P O'Leary
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Hector M Mantolino
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Kurt R Stover
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Richard E Brown
- Department of Psychology and Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
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29
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Saraulli D, Costanzi M, Mastrorilli V, Farioli-Vecchioli S. The Long Run: Neuroprotective Effects of Physical Exercise on Adult Neurogenesis from Youth to Old Age. Curr Neuropharmacol 2018; 15:519-533. [PMID: 27000776 PMCID: PMC5543673 DOI: 10.2174/1570159x14666160412150223] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Revised: 03/08/2016] [Accepted: 03/16/2016] [Indexed: 01/17/2023] Open
Abstract
BACKGROUND The rapid lengthening of life expectancy has raised the problem of providing social programs to counteract the age-related cognitive decline in a growing number of older people. Physical activity stands among the most promising interventions aimed at brain wellbeing, because of its effective neuroprotective action and low social cost. The purpose of this review is to describe the neuroprotective role exerted by physical activity in different life stages. In particular, we focus on adult neurogenesis, a process which has proved being highly responsive to physical exercise and may represent a major factor of brain health over the lifespan. METHODS The most recent literature related to the subject has been reviewed. The text has been divided into three main sections, addressing the effects of physical exercise during childhood/ adolescence, adulthood and aging, respectively. For each one, the most relevant studies, carried out on both human participants and rodent models, have been described. RESULTS The data reviewed converge in indicating that physical activity exerts a positive effect on brain functioning throughout the lifespan. However, uncertainty remains about the magnitude of the effect and its biological underpinnings. Cellular and synaptic plasticity provided by adult neurogenesis are highly probable mediators, but the mechanism for their action has yet to be conclusively established. CONCLUSION Despite alternative mechanisms of action are currently debated, age-appropriate physical activity programs may constitute a large-scale, relatively inexpensive and powerful approach to dampen the individual and social impact of age-related cognitive decline.
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Affiliation(s)
- Daniele Saraulli
- Institute of Cell Biology and Neurobiology, National Research Council, & Fondazione S. Lucia, Rome. Italy
| | - Marco Costanzi
- Department of Human Sciences, LUMSA University, Rome. Italy
| | - Valentina Mastrorilli
- Institute of Cell Biology and Neurobiology, National Research Council, & Fondazione S. Lucia, Rome. Italy
| | - Stefano Farioli-Vecchioli
- Institute of Cell Biology and Neurobiology, National Research Council, Via del Fosso di Fiorano 64, 00143 Rome. Italy
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30
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Hoeijmakers L, Meerhoff GF, de Vries JW, Ruigrok SR, van Dam AM, van Leuven F, Korosi A, Lucassen PJ. The age-related slow increase in amyloid pathology in APP.V717I mice activates microglia, but does not alter hippocampal neurogenesis. Neurobiol Aging 2018; 61:112-123. [DOI: 10.1016/j.neurobiolaging.2017.09.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2017] [Revised: 09/12/2017] [Accepted: 09/14/2017] [Indexed: 01/09/2023]
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31
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Salmin VV, Komleva YK, Kuvacheva NV, Morgun AV, Khilazheva ED, Lopatina OL, Pozhilenkova EA, Shapovalov KA, Uspenskaya YA, Salmina AB. Differential Roles of Environmental Enrichment in Alzheimer's Type of Neurodegeneration and Physiological Aging. Front Aging Neurosci 2017; 9:245. [PMID: 28798684 PMCID: PMC5526976 DOI: 10.3389/fnagi.2017.00245] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Accepted: 07/14/2017] [Indexed: 12/21/2022] Open
Abstract
Impairment of hippocampal adult neurogenesis in aging or degenerating brain is a well-known phenomenon caused by the shortage of brain stem cell pool, alterations in the local microenvironment within the neurogenic niches, or deregulation of stem cell development. Environmental enrichment (EE) has been proposed as a potent tool to restore brain functions, to prevent aging-associated neurodegeneration, and to cure neuronal deficits seen in neurodevelopmental and neurodegenerative disorders. Here, we report our data on the effects of environmental enrichment on hippocampal neurogenesis in vivo and neurosphere-forming capacity of hippocampal stem/progenitor cells in vitro. Two models - Alzheimer's type of neurodegeneration and physiological brain aging - were chosen for the comparative analysis of EE effects. We found that environmental enrichment greatly affects the expression of markers specific for stem cells, progenitor cells and differentiated neurons (Pax6, Ngn2, NeuroD1, NeuN) in the hippocampus of young adult rats or rats with Alzheimer's disease (AD) model but less efficiently in aged animals. Application of time-lag mathematical model for the analysis of impedance traces obtained in real-time monitoring of cell proliferation in vitro revealed that EE could restore neurosphere-forming capacity of hippocampal stem/progenitor cells more efficiently in young adult animals (fourfold greater in the control group comparing to the AD model group) but not in the aged rats (no positive effect of environmental enrichment at all). In accordance with the results obtained in vivo, EE was almost ineffective in the recovery of hippocampal neurogenic reserve in vitro in aged, but not in amyloid-treated or young adult, rats. Therefore, EE-based neuroprotective strategies effective in Aβ-affected brain could not be directly extrapolated to aged brain.
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Affiliation(s)
- Vladimir V Salmin
- Department of Medical and Biological Physics, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Yulia K Komleva
- Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Natalia V Kuvacheva
- Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Andrey V Morgun
- Department of Pediatrics, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Elena D Khilazheva
- Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Olga L Lopatina
- Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Elena A Pozhilenkova
- Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Konstantin A Shapovalov
- Department of Medical and Biological Physics, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Yulia A Uspenskaya
- Research Institute of Molecular Medicine and Pathobiochemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
| | - Alla B Salmina
- Department of Biochemistry, Medical, Pharmaceutical and Toxicological Chemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia.,Research Institute of Molecular Medicine and Pathobiochemistry, Krasnoyarsk State Medical University named after Prof. V.F. Voino-YasenetskyKrasnoyarsk, Russia
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32
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Stuart KE, King AE, Fernandez-Martos CM, Summers MJ, Vickers JC. Environmental novelty exacerbates stress hormones and Aβ pathology in an Alzheimer's model. Sci Rep 2017; 7:2764. [PMID: 28584278 PMCID: PMC5459800 DOI: 10.1038/s41598-017-03016-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2016] [Accepted: 04/21/2017] [Indexed: 01/06/2023] Open
Abstract
Cognitive stimulation has been proposed as a non-pharmacological intervention to be used in primary, secondary and tertiary prevention approaches for Alzheimer's disease. A common familial Alzheimer's disease transgenic model showed heightened levels of the stress hormone, corticosterone. When exposed to periodic enhanced cognitive stimulation, these animals demonstrated further heightened levels of corticosterone as well as increased Aβ pathology. Hence, Alzheimer's disease may be associated with hypothalamic-pituitary-adrenal (HPA) axis dysfunction, causing stimulatory environments to become stress-inducing, leading to a glucocorticoid-pathology cycle contributing to further Aβ release and plaque formation. This finding suggests that stimulation-based interventions and local environments for people with Alzheimer's disease need to be designed to minimise a stress response that may exacerbate brain pathology.
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Affiliation(s)
- Kimberley E Stuart
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia.
| | - Anna E King
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Carmen M Fernandez-Martos
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
| | - Mathew J Summers
- School of Social Sciences, University of the Sunshine Coast, Sippy Downs, Queensland, 4556, Australia
| | - James C Vickers
- Wicking Dementia Research and Education Centre, Faculty of Health, University of Tasmania, Tasmania, 7000, Australia
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33
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Acevedo-Triana CA, Rojas MJ, Cardenas FP. Running wheel training does not change neurogenesis levels or alter working memory tasks in adult rats. PeerJ 2017; 5:e2976. [PMID: 28503368 PMCID: PMC5426350 DOI: 10.7717/peerj.2976] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 01/10/2017] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND Exercise can change cellular structure and connectivity (neurogenesis or synaptogenesis), causing alterations in both behavior and working memory. The aim of this study was to evaluate the effect of exercise on working memory and hippocampal neurogenesis in adult male Wistar rats using a T-maze test. METHODS An experimental design with two groups was developed: the experimental group (n = 12) was subject to a forced exercise program for five days, whereas the control group (n = 9) stayed in the home cage. Six to eight weeks after training, the rats' working memory was evaluated in a T-maze test and four choice days were analyzed, taking into account alternation as a working memory indicator. Hippocampal neurogenesis was evaluated by means of immunohistochemistry of BrdU positive cells. RESULTS No differences between groups were found in the behavioral variables (alternation, preference index, time of response, time of trial or feeding), or in the levels of BrdU positive cells. DISCUSSION Results suggest that although exercise may have effects on brain structure, a construct such as working memory may require more complex changes in networks or connections to demonstrate a change at behavioral level.
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Affiliation(s)
| | - Manuel J. Rojas
- Animal Health Department, Universidad Nacional de Colombia, Bogotá, Colombia
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34
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Wirths O. Altered neurogenesis in mouse models of Alzheimer disease. NEUROGENESIS 2017; 4:e1327002. [PMID: 29564360 DOI: 10.1080/23262133.2017.1327002] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 04/28/2017] [Accepted: 04/28/2017] [Indexed: 10/19/2022]
Abstract
Amyloid-β (Aβ) peptides, as well as a variety of other protein fragments, are derived from proteolytical cleavage of the amyloid precursor protein (APP) and have been demonstrated to play a key role in the pathological changes underlying Alzheimer disease (AD). In AD mouse models, altered neurogenesis has been repeatedly reported to be associated with further AD-typical pathological hallmarks such as extracellular plaque deposition, behavioral deficits or neuroinflammation. While a toxic role of Aβ in neurodegeneration and impaired neuronal progenitor proliferation is likely and well-accepted, recent findings also suggest an important influence of APP-derived proteolitical fragments like the APP intracellular domain (AICD), as well as of APP itself.
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Affiliation(s)
- Oliver Wirths
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center (UMG), Georg-August-University, Göttingen, Germany
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35
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Stuart KE, King AE, Fernandez-Martos CM, Dittmann J, Summers MJ, Vickers JC. Mid-life environmental enrichment increases synaptic density in CA1 in a mouse model of Aβ-associated pathology and positively influences synaptic and cognitive health in healthy ageing. J Comp Neurol 2017; 525:1797-1810. [DOI: 10.1002/cne.24156] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 11/09/2016] [Accepted: 11/10/2016] [Indexed: 12/22/2022]
Affiliation(s)
- Kimberley E. Stuart
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Anna E. King
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Carmen M. Fernandez-Martos
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Justin Dittmann
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
| | - Mathew J. Summers
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
- School of Social Sciences; University of the Sunshine Coast; Sippy Downs Queensland Australia
| | - James C. Vickers
- Faculty of Health; Wicking Dementia Research and Education Centre, University of Tasmania; Tasmania Australia
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36
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DePasquale C, Neuberger T, Hirrlinger AM, Braithwaite VA. The influence of complex and threatening environments in early life on brain size and behaviour. Proc Biol Sci 2016; 283:rspb.2015.2564. [PMID: 26817780 PMCID: PMC4795028 DOI: 10.1098/rspb.2015.2564] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The ways in which challenging environments during development shape the brain and behaviour are increasingly being addressed. To date, studies typically consider only single variables, but the real world is more complex. Many factors simultaneously affect the brain and behaviour, and whether these work independently or interact remains untested. To address this, zebrafish (Danio rerio) were reared in a two-by-two design in housing that varied in structural complexity and/or exposure to a stressor. Fish experiencing both complexity (enrichment objects changed over time) and mild stress (daily net chasing) exhibited enhanced learning and were less anxious when tested as juveniles (between 77 and 90 days). Adults tested (aged 1 year) were also less anxious even though fish were kept in standard housing after three months of age (i.e. no chasing or enrichment). Volumetric measures of the brain using magnetic resonance imaging (MRI) showed that complexity alone generated fish with a larger brain, but this increase in size was not seen in fish that experienced both complexity and chasing, or chasing alone. The results highlight the importance of looking at multiple variables simultaneously, and reveal differential effects of complexity and stressful experiences during development of the brain and behaviour.
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Affiliation(s)
- C DePasquale
- Department of Biology, Pennsylvania State University-Altoona, Altoona, PA, USA Center for Brain, Behavior, and Cognition, Pennsylvania State University, University Park, PA, USA Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, USA
| | - T Neuberger
- Huck Institutes of the Life Sciences, Pennsylvania State University, University Park, PA, USA Department of Bioengineering, Pennsylvania State University, University Park, PA, USA
| | - A M Hirrlinger
- Department of Biology, Pennsylvania State University, University Park, PA, USA
| | - V A Braithwaite
- Center for Brain, Behavior, and Cognition, Pennsylvania State University, University Park, PA, USA Department of Ecosystem Science and Management, Pennsylvania State University, University Park, PA, USA Department of Biology, Pennsylvania State University, University Park, PA, USA
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37
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Hüttenrauch M, Walter S, Kaufmann M, Weggen S, Wirths O. Limited Effects of Prolonged Environmental Enrichment on the Pathology of 5XFAD Mice. Mol Neurobiol 2016; 54:6542-6555. [DOI: 10.1007/s12035-016-0167-x] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Accepted: 09/27/2016] [Indexed: 10/20/2022]
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38
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Bernardo TC, Marques-Aleixo I, Beleza J, Oliveira PJ, Ascensão A, Magalhães J. Physical Exercise and Brain Mitochondrial Fitness: The Possible Role Against Alzheimer's Disease. Brain Pathol 2016; 26:648-63. [PMID: 27328058 PMCID: PMC8029062 DOI: 10.1111/bpa.12403] [Citation(s) in RCA: 64] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2016] [Accepted: 06/15/2016] [Indexed: 12/21/2022] Open
Abstract
Exercise is one of the most effective strategies to maintain a healthy body and mind, with particular beneficial effects of exercise on promoting brain plasticity, increasing cognition and reducing the risk of cognitive decline and dementia in later life. Moreover, the beneficial effects resulting from increased physical activity occur at different levels of cellular organization, mitochondria being preferential target organelles. The relevance of this review article relies on the need to integrate the current knowledge of proposed mechanisms, focus mitochondria, to explain the protective effects of exercise that might underlie neuroplasticity and seeks to synthesize these data in the context of exploring exercise as a feasible intervention to delay cognitive impairment associated with neurodegenerative conditions, particularly Alzheimer disease.
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Affiliation(s)
- T C Bernardo
- CIAFEL-Research Centre in Physical Activity, , Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal.
| | - I Marques-Aleixo
- CIAFEL-Research Centre in Physical Activity, , Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - J Beleza
- CIAFEL-Research Centre in Physical Activity, , Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - P J Oliveira
- CNC-Centre for Neuroscience and Cell Biology, UC-Biotech, Biocant Park, University of Coimbra, Coimbra, Portugal
| | - A Ascensão
- CIAFEL-Research Centre in Physical Activity, , Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
| | - J Magalhães
- CIAFEL-Research Centre in Physical Activity, , Health and Leisure, Faculty of Sport, University of Porto, Porto, Portugal
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Hüttenrauch M, Salinas G, Wirths O. Effects of Long-Term Environmental Enrichment on Anxiety, Memory, Hippocampal Plasticity and Overall Brain Gene Expression in C57BL6 Mice. Front Mol Neurosci 2016; 9:62. [PMID: 27536216 PMCID: PMC4971077 DOI: 10.3389/fnmol.2016.00062] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 07/15/2016] [Indexed: 01/09/2023] Open
Abstract
There is ample evidence that physical activity exerts positive effects on a variety of brain functions by facilitating neuroprotective processes and influencing neuroplasticity. Accordingly, numerous studies have shown that continuous exercise can successfully diminish or prevent the pathology of neurodegenerative diseases such as Alzheimer’s disease in transgenic mouse models. However, the long-term effect of physical activity on brain health of aging wild-type (WT) mice has not yet been studied in detail. Here, we show that prolonged physical and cognitive stimulation, mediated by an enriched environment (EE) paradigm for a duration of 11 months, leads to reduced anxiety and improved spatial reference memory in C57BL6 WT mice. While the number of CA1 pyramidal neurons remained unchanged between standard housed (SH) and EE mice, the number of dentate gyrus (DG) neurons, as well as the CA1 and DG volume were significantly increased in EE mice. A whole-brain deep sequencing transcriptome analysis, carried out to better understand the molecular mechanisms underlying the observed effects, revealed an up-regulation of a variety of genes upon EE, mainly associated with synaptic plasticity and transcription regulation. The present findings corroborate the impact of continuous physical activity as a potential prospective route in the prevention of age-related cognitive decline and neurodegenerative disorders.
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Affiliation(s)
- Melanie Hüttenrauch
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center, Georg-August-University Göttingen, Germany
| | - Gabriela Salinas
- Department of Developmental Biochemistry, DNA Microarray and Deep-Sequencing Facility, University Medical Center Göttingen, Germany
| | - Oliver Wirths
- Division of Molecular Psychiatry, Department of Psychiatry and Psychotherapy, University Medical Center, Georg-August-University Göttingen, Germany
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40
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Hüttenrauch M, Brauß A, Kurdakova A, Borgers H, Klinker F, Liebetanz D, Salinas-Riester G, Wiltfang J, Klafki HW, Wirths O. Physical activity delays hippocampal neurodegeneration and rescues memory deficits in an Alzheimer disease mouse model. Transl Psychiatry 2016; 6:e800. [PMID: 27138799 PMCID: PMC5070068 DOI: 10.1038/tp.2016.65] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Accepted: 03/11/2016] [Indexed: 01/12/2023] Open
Abstract
The evidence for a protective role of physical activity on the risk and progression of Alzheimer's disease (AD) has been growing in the last years. Here we studied the influence of a prolonged physical and cognitive stimulation on neurodegeneration, with special emphasis on hippocampal neuron loss and associated behavioral impairment in the Tg4-42 mouse model of AD. Tg4-42 mice overexpress Aβ4-42 without any mutations, and develop an age-dependent hippocampal neuron loss associated with a severe memory decline. We demonstrate that long-term voluntary exercise diminishes CA1 neuron loss and completely rescues spatial memory deficits in different experimental settings. This was accompanied by changes in the gene expression profile of Tg4-42 mice. Deep sequencing analysis revealed an upregulation of chaperones involved in endoplasmatic reticulum protein processing, which might be intimately linked to the beneficial effects seen upon long-term exercise. We believe that we provide evidence for the first time that enhanced physical activity counteracts neuron loss and behavioral deficits in a transgenic AD mouse model. The present findings underscore the relevance of increased physical activity as a potential strategy in the prevention of dementia.
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Affiliation(s)
- M Hüttenrauch
- Department of Psychiatry and
Psychotherapy, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
| | - A Brauß
- Department of Psychiatry and
Psychotherapy, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
| | - A Kurdakova
- Department of Psychiatry and
Psychotherapy, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
| | - H Borgers
- Department of Psychiatry and
Psychotherapy, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
| | - F Klinker
- Department of Clinical
Neurophysiology, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
| | - D Liebetanz
- Department of Clinical
Neurophysiology, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
| | - G Salinas-Riester
- Department of Developmental
Biochemistry, DNA Microarray and Deep-Sequencing Facility, University
Medical Center (UMG), Georg-August-University,
Göttingen, Germany
| | - J Wiltfang
- Department of Psychiatry and
Psychotherapy, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
- German Center for Neurodegenerative
Diseases (DZNE), Göttingen, Germany
| | - H W Klafki
- Department of Psychiatry and
Psychotherapy, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
| | - O Wirths
- Department of Psychiatry and
Psychotherapy, University Medical Center (UMG),
Georg-August-University, Göttingen,
Germany
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Noise exposure of immature rats can induce different age-dependent extra-auditory alterations that can be partially restored by rearing animals in an enriched environment. Brain Res 2016; 1636:52-61. [PMID: 26851548 DOI: 10.1016/j.brainres.2016.01.050] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 12/29/2015] [Accepted: 01/27/2016] [Indexed: 02/01/2023]
Abstract
It has been previously shown that different extra-auditory alterations can be induced in animals exposed to noise at 15 days. However, data regarding exposure of younger animals, that do not have a functional auditory system, have not been obtained yet. Besides, the possibility to find a helpful strategy to restore these changes has not been explored so far. Therefore, the aims of the present work were to test age-related differences in diverse hippocampal-dependent behavioral measurements that might be affected in noise-exposed rats, as well as to evaluate the effectiveness of a potential neuroprotective strategy, the enriched environment (EE), on noise-induced behavioral alterations. Male Wistar rats of 7 and 15 days were exposed to moderate levels of noise for two hours. At weaning, animals were separated and reared either in standard or in EE cages for one week. At 28 days of age, different hippocampal-dependent behavioral assessments were performed. Results show that rats exposed to noise at 7 and 15 days were differentially affected. Moreover, EE was effective in restoring all altered variables when animals were exposed at 7 days, while a few were restored in rats exposed at 15 days. The present findings suggest that noise exposure was capable to trigger significant hippocampal-related behavioral alterations that were differentially affected, depending on the age of exposure. In addition, it could be proposed that hearing structures did not seem to be necessarily involved in the generation of noise-induced hippocampal-related behaviors, as they were observed even in animals with an immature auditory pathway. Finally, it could be hypothesized that the differential restoration achieved by EE rearing might also depend on the degree of maturation at the time of exposure and the variable evaluated, being younger animals more susceptible to environmental manipulations.
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42
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Neuroinflammation negatively affects adult hippocampal neurogenesis and cognition: can exercise compensate? Neurosci Biobehav Rev 2016; 61:121-31. [DOI: 10.1016/j.neubiorev.2015.12.004] [Citation(s) in RCA: 125] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 11/20/2015] [Accepted: 12/09/2015] [Indexed: 01/09/2023]
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43
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Environmental enrichment as a method to improve cognitive function. What can we learn from animal models? Neuroimage 2015; 131:42-7. [PMID: 26656208 DOI: 10.1016/j.neuroimage.2015.11.039] [Citation(s) in RCA: 56] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 11/12/2015] [Accepted: 11/15/2015] [Indexed: 01/21/2023] Open
Abstract
There is substantial evidence that physical and cognitive exercise can enhance memory function in rodents as well as in humans. In addition various behaviors associated with physical activity have been associated with an increased cognitive reserve and a lower risk to develop age-associated memory decline and age-associated neurodegenerative diseases such as Alzheimer's disease. To better understand the molecular mechanisms that increase brain plasticity in response to exercise will therefore help to develop effective therapeutic strategies to treat memory decline. Here we review the currently available data with a specific focus on neurodegenerative diseases.
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44
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Cognitive Reserve and Alzheimer’s Disease. Mol Neurobiol 2014; 51:187-208. [DOI: 10.1007/s12035-014-8720-y] [Citation(s) in RCA: 72] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2014] [Accepted: 04/17/2014] [Indexed: 12/13/2022]
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45
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Herholz SC, Herholz RS, Herholz K. Non-pharmacological interventions and neuroplasticity in early stage Alzheimer's disease. Expert Rev Neurother 2014; 13:1235-45. [DOI: 10.1586/14737175.2013.845086] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
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46
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Opposing actions of environmental enrichment and Alzheimer's disease on the expression of hippocampal microRNAs in mouse models. Transl Psychiatry 2013; 3:e304. [PMID: 24022509 PMCID: PMC3784766 DOI: 10.1038/tp.2013.77] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Accepted: 07/19/2013] [Indexed: 12/18/2022] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly. Although there are no drugs that modify the disease process, exposure to an enriched environment (EE) can slow the disease progression. Here, we characterize the effects of AD and EE on the post-transcriptional regulators, microRNAs (miRNAs), which may contribute to the detrimental and beneficial effects of AD and EE, respectively, on synaptic plasticity-related proteins and AD pathology. We found for the first time miRNAs that were inversely regulated in AD and EE, and may affect synaptic proteins and modulators, molecular factors associated with AD pathology, and survival and neuroprotective factors. MiRNAs that were upregulated only in 3xTgAD mice model of AD compared with their control mice were localized to synapses, predicted to downregulate essential synaptic proteins and are highly associated with regulating apoptosis, AD-associated processes and axon guidance. Studying the progressive change in miRNAs modulation during aging of 3xTgAD mice, we identified miRNAs that were regulated in earlier stages of AD, suggesting them as potential AD biomarkers. Last, we characterized AD- and EE-related effects in the mouse hippocampus on tomosyn protein levels, an inhibitor of the synaptic transmission machinery. While EE reduced tomosyn levels, tomosyn levels were increased in old 3xTgAD mice, suggesting a role for tomosyn in the impairment of synaptic transmission in AD. Interestingly, we found that miR-325 regulates the expression levels of tomosyn as demonstrated by a luciferase reporter assay, and that miR-325 was downregulated in AD and upregulated following EE. These findings improve our understanding of the molecular and cellular processes in AD pathology, following EE, and the interplay between the two processes, and open new avenues for the studies of understanding and controlling AD.
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47
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Montarolo F, Parolisi R, Hoxha E, Boda E, Tempia F. Early enriched environment exposure protects spatial memory and accelerates amyloid plaque formation in APP(Swe)/PS1(L166P) mice. PLoS One 2013; 8:e69381. [PMID: 23894463 PMCID: PMC3722266 DOI: 10.1371/journal.pone.0069381] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2013] [Accepted: 06/07/2013] [Indexed: 02/05/2023] Open
Abstract
Enriched environment exposure improves several aspects of cognitive performance in Alzheimer’s disease patients and in animal models and, although the role of amyloid plaques is questionable, several studies also assessed their response to enriched environment, with contrasting results. Here we report that rearing APPSwe/PS1L166P mice in an enriched environment since birth rescued the spatial memory impairment otherwise present at 6 months of age. At the same time, the exposure to the enriched environment caused a transient acceleration of plaque formation, while there was no effect on intracellular staining with the 6E10 antibody, which recognizes β-amyloid, full length amyloid precursor protein and its C-terminal fragments. The anticipation of plaque formation required exposure during early development, suggesting an action within critical periods for circuits formation. On the other hand, chronic neuronal activity suppression by tetrodotoxin decreased the number of plaques without affecting intracellular amyloid. These results indicate that enriched environment exposure since early life has a protective effect on cognitive deterioration although transiently accelerates amyloid deposition. In addition, the effects of the enriched environment might be due to increased neuronal activity, because plaques were reduced by suppression of electrical signaling by tetrodotoxin.
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Affiliation(s)
- Francesca Montarolo
- Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano (Torino), Italy
| | - Roberta Parolisi
- Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano (Torino), Italy
| | - Eriola Hoxha
- Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano (Torino), Italy
| | - Enrica Boda
- Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano (Torino), Italy
| | - Filippo Tempia
- Institute Cavalieri Ottolenghi (NICO), University of Torino, Orbassano (Torino), Italy
- Department of Neuroscience and National Institute of Neuroscience-Italy (INN), University of Torino, Torino, Italy
- * E-mail:
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48
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Gerenu G, Dobarro M, Ramirez MJ, Gil-Bea FJ. Early cognitive stimulation compensates for memory and pathological changes in Tg2576 mice. BIOCHIMICA ET BIOPHYSICA ACTA 2013; 1832:837-47. [PMID: 23474306 DOI: 10.1016/j.bbadis.2013.02.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2013] [Revised: 02/12/2013] [Accepted: 02/26/2013] [Indexed: 10/27/2022]
Abstract
Education and cognitive occupations are commonly associated to reduce risk of Alzheimer's disease (AD) or dementia. Animal studies have demonstrated that cognitive stimulation (CS) achieved by social/physical activities and/or enriched environments compensates for memory decline. We have elaborated a novel paradigm of CS that is devoid of physical/social activity and enriched environments. 4 month-old Tg2576 mice were cognitively trained for 8 weeks and, after a break of 8 months, long-lasting effects of CS on cognitive abilities and AD-like pathology were measured. Morris Water Maze (MWM) and Novel Object Recognition (NOR) tests showed that deficits in spatial and recognition memories were compensated by CS. These outcomes were accompanied by increased levels of hippocampal post-synaptic markers (PSD95 and NR1) and proteins involved in synaptic formation (Arc, β-catenin). CS softened amyloid pathology in terms of reduced levels of Aβ1-42 and the dodecameric assembly, referred as Aβ*56. CS appeared to affect the APP processing since differences in levels of ADAM17, BACE1 and C99/C83 ratio were found. Tau hyper-phosphorylation and high activities of tau kinases were also reduced by CS. In contrast, CS did not induce any of these molecular changes in wild-type mice. The present findings suggest beneficial and long-lasting effects of CS early in life on cognitive decline and AD-like pathology.
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Affiliation(s)
- Gorka Gerenu
- Department of Pharmacology, University of Navarra, Pamplona, Spain
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49
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Yuan Q, Su H, Chau WH, Toa Ng C, Huang JD, Wu W, Lin ZX. Behavioral stress fails to accelerate the onset and progression of plaque pathology in the brain of a mouse model of Alzheimer's disease. PLoS One 2013; 8:e53480. [PMID: 23326437 PMCID: PMC3543430 DOI: 10.1371/journal.pone.0053480] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Accepted: 11/30/2012] [Indexed: 11/18/2022] Open
Abstract
Conflicting findings exist regarding the link between environmental factors and development of Alzheimer's disease (AD) in a variety of transgenic mouse models of AD. In the present study, we investigated the effect of behavioral stress on the onset and progression of Aβ pathology in the brains of TgCRND8 mice, a transgenic mouse model of AD. One group of TgCRND8 mice was subjected to restraint stress starting at 1 month of age until they were 3 months old, while restraint stress in the second group started at 4 months of age until they were 6 months old. After 2 months of treatment, no differences in the soluble, formic acid extracted, or histologically detected Aβ deposition in the cortical and hippocampal levels were found between non-stressed and stressed mice. These results showed that restraint stress alone failed to aggravate amyloid pathology when initiated either before or after the age of amyloid plaque deposition in TgCRND8 mice, suggesting that if stress aggravated AD phenotype, it may not be via an amyloid-related mechanism in the TgCRND8 mice. These findings are indicative that plaque load per se may not be used as a significant criterion for evaluating the effect of stress on AD patients.
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MESH Headings
- Aging/pathology
- Alzheimer Disease/blood
- Alzheimer Disease/complications
- Alzheimer Disease/pathology
- Alzheimer Disease/psychology
- Amyloid beta-Peptides/metabolism
- Animals
- Behavior, Animal
- Brain/metabolism
- Brain/pathology
- Cerebral Cortex/metabolism
- Cerebral Cortex/pathology
- Corticosterone/blood
- Disease Models, Animal
- Disease Progression
- Humans
- Hypothalamus/metabolism
- Hypothalamus/pathology
- Mice
- Mice, Transgenic
- Neurons/metabolism
- Neurons/pathology
- Plaque, Amyloid/blood
- Plaque, Amyloid/complications
- Plaque, Amyloid/pathology
- Proto-Oncogene Proteins c-fos/metabolism
- Restraint, Physical
- Stress, Psychological/blood
- Stress, Psychological/complications
- Stress, Psychological/pathology
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Affiliation(s)
- Qiuju Yuan
- School of Chinese Medicine, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, China
| | - Huanxing Su
- State Key Laboratory of Quality Research in Chinese Medicine and Institute of Chinese Medical Sciences, University of Macau, Macao, China
| | - Wing Hin Chau
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Cheung Toa Ng
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Jian-Dong Huang
- Department of Biochemistry, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
| | - Wutian Wu
- Department of Anatomy, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- State Key Laboratory of Brain and Cognitive Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- Research Center of Reproduction, Development and Growth, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong, China
- Institute of Central Nervous System Regeneration, Jinan University, Guangzhou, China
- * E-mail: (WW); (Z-XL)
| | - Zhi-Xiu Lin
- School of Chinese Medicine, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, China
- * E-mail: (WW); (Z-XL)
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50
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Beauquis J, Pavía P, Pomilio C, Vinuesa A, Podlutskaya N, Galvan V, Saravia F. Environmental enrichment prevents astroglial pathological changes in the hippocampus of APP transgenic mice, model of Alzheimer's disease. Exp Neurol 2013; 239:28-37. [PMID: 23022919 DOI: 10.1016/j.expneurol.2012.09.009] [Citation(s) in RCA: 119] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2012] [Revised: 09/04/2012] [Accepted: 09/20/2012] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that affects neurons and glial cells and leads to dementia. Growing evidence shows that glial changes may precede neuronal alterations and behavioral impairment in the progression of the disease. The modulation of these changes could be addressed as a potential therapeutic strategy. Environmental enrichment has been classically associated to effects on neuronal morphology and function but less attention has been paid to the modulation of glia. We thus characterized astroglial changes in the hippocampus of adult PDAPP-J20 transgenic mice, a model of AD, exposed for 3 months to an enriched environment, from 5 to 8 months of age. Using confocal microscopy, three-dimensional reconstruction and Sholl analysis, we evaluated the morphology of two distinct populations of astrocytes: those associated to amyloid β plaques and those that were not. We found that plaque-associated astrocytes in PDAPP-J20 mice had an increased volume and process ramification than control astrocytes. Non-plaque-associated astrocytes showed a decrease in volume and an increase in the ramification of GFAP+ processes as compared with control astrocytes. Environmental enrichment prevented these alterations and promoted a cellular morphology similar to that found in control mice. Morphological changes in non-plaque-associated astrocytes were found also at 5 months of age, before amyloid β deposition in the hippocampus. These results suggest that glial alterations have an early onset in AD pathogenesis and that the exposure to an enriched environment is an appropriate strategy to reverse them. Cellular and molecular pathways involved in this regulation could constitute potential novel therapeutic targets.
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Affiliation(s)
- Juan Beauquis
- Laboratorio de Neurobiología, Departamento de Química Biológica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina
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