1
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Zhang RL, Lei BX, Wu GY, Wang YY, Huang QH. Protective effects of berberine against β-amyloid-induced neurotoxicity in HT22 cells via the Nrf2/HO-1 pathway. Bioorg Chem 2023; 133:106210. [PMID: 36724611 DOI: 10.1016/j.bioorg.2022.106210] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 09/21/2022] [Accepted: 10/11/2022] [Indexed: 02/03/2023]
Abstract
Neuronal apoptosis has been found to have a pivotal role in the course of Alzheimer's disease (AD). Berberine (BBR), a potent antioxidant, occurs in plants such as Berberis, Phellodendron chinense, and Hydrastis canadensis. In this study, a neuronal apoptotic model was established in vitro using HT22 cells induced by Aβ25-35 to explore whether BBR contributes to protecting neurons against Aβ25-35-induced neurotoxicity, as well as its potential mechanisms. BBR was applied to HT22 cells for 1 h prior to exposing the cells to Aβ25-35 for 24 h. A CCK-8 assay was utilized to assess cell viability, and Annexin V - fluorescein isothiocyanate (FITC)/propidium iodide and Hoechst 33342 fluorescence staining were used to measure the rate of cell apoptosis. Existing scientific literature was also reviewed to further determine the effects of BBR on ROS production and mitochondrial function in HT22 cells. Furthermore, the expressions of proteins, including cytochrome C, cleaved caspase-3, p-p65, p65, and Nrf2/HO-1 antioxidant axis were assessed by Western blotting. The data indicated that BBR markedly improved cell viability, inhibited apoptosis and intracellular ROS levels, improved mitochondrial membrane potentials, decreased the rate of p-p65/p65, cytochrome C, and cleaved caspase-3, and intensified the activity of Nrf2/HO-1 antioxidants in HT22 cells. Overall, the findings indicated that BBR provides a certain level of neuroprotectiveness in HT22 cells exposed to Aβ25-35 via relieving oxidative stress, as well as by restraining the mitochondrial pathway of cellular apoptosis. In addition, the restraint of NF-κB activity and sensitization of the Nrf2/HO-1 antioxidant axis, which together are intimately involved in the neuroprotection of BBR, may be possible mechanisms accounting for its effectiveness against Aβ25-35in vitro.
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Affiliation(s)
- Ru-Lan Zhang
- Department of Chinese Medicine, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, China
| | - Bing-Xi Lei
- Department of Neurosurgery, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province 510120, China
| | - Guo-Yong Wu
- Department of Thoracic Surgery, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, China
| | - Yuan-Yuan Wang
- Department of Chinese Medicine, the First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province 510080, China
| | - Qi-Hui Huang
- Department of Chinese Medicine, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province 510120, China.
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2
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Freire-Cobo C, Rothwell ES, Varghese M, Edwards M, Janssen WGM, Lacreuse A, Hof PR. Neuronal vulnerability to brain aging and neurodegeneration in cognitively impaired marmoset monkeys (Callithrix jacchus). Neurobiol Aging 2023; 123:49-62. [PMID: 36638681 PMCID: PMC9892246 DOI: 10.1016/j.neurobiolaging.2022.12.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Revised: 12/01/2022] [Accepted: 12/01/2022] [Indexed: 12/24/2022]
Abstract
The investigation of neurobiological and neuropathological changes that affect synaptic integrity and function with aging is key to understanding why the aging brain is vulnerable to Alzheimer's disease. We investigated the cellular characteristics in the cerebral cortex of behaviorally characterized marmosets, based on their trajectories of cognitive learning as they transitioned to old age. We found increased astrogliosis, increased phagocytic activity of microglial cells and differences in resting and reactive microglial cell phenotypes in cognitively impaired compared to nonimpaired marmosets. Differences in amyloid beta deposition were not related to cognitive trajectory. However, we found age-related changes in density and morphology of dendritic spines in pyramidal neurons of layer 3 in the dorsolateral prefrontal cortex and the CA1 field of the hippocampus between cohorts. Overall, our data suggest that an accelerated aging process, accompanied by neurodegeneration, that takes place in cognitively impaired aged marmosets and affects the plasticity of dendritic spines in cortical areas involved in cognition and points to mechanisms of neuronal vulnerability to aging.
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Affiliation(s)
- Carmen Freire-Cobo
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA.
| | - Emily S Rothwell
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - Merina Varghese
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Mélise Edwards
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - William G M Janssen
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | - Agnès Lacreuse
- Department of Psychological and Brain Sciences, University of Massachusetts, Amherst, MA, USA
| | - Patrick R Hof
- Nash Family Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA; Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY, USA
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3
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Chwa WJ, Lopez OL, Longstreth W, Dai W, Raji CA. Longitudinal Patterns of Brain Changes in a Community Sample in Relation to Aging and Cognitive Status. J Alzheimers Dis 2023; 94:1035-1045. [PMID: 37355895 PMCID: PMC10674101 DOI: 10.3233/jad-230080] [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] [Indexed: 06/26/2023]
Abstract
BACKGROUND Aging and Alzheimer's disease (AD) are characterized by widespread cortical and subcortical atrophy. Though atrophy patterns between aging and AD overlap considerably, regional differences between these two conditions may exist. Few studies, however, have investigated these patterns in large community samples. OBJECTIVE Elaborate longitudinal changes in brain morphometry in relation to aging and cognitive status in a well-characterized community cohort. METHODS Clinical and neuroimaging data were compiled from 72 participants from the Cardiovascular Health Study-Cognition Study, a community cohort of healthy aging and probable AD participants. Two time points were identified for each participant with a mean follow-up time of 5.36 years. MRI post-processing, morphometric measurements, and statistical analyses were performed using FreeSurfer, Version 7.1.1. RESULTS Cortical volume was significantly decreased in the bilateral superior frontal, bilateral inferior parietal, and left superior parietal regions, among others. Cortical thickness was significantly reduced in the bilateral superior frontal and left inferior parietal regions, among others. Overall gray and white matter volumes and hippocampal subfields also demonstrated significant reductions. Cortical volume atrophy trajectories between cognitively stable and cognitively declined participants were significantly different in the right postcentral region. CONCLUSION Observed volume reductions were consistent with previous studies investigating morphometric brain changes. Patterns of brain atrophy between AD and aging may be different in magnitude but exhibit widespread spatial overlap. These findings help characterize patterns of brain atrophy that may reflect the general population. Larger studies may more definitively establish population norms of aging and AD-related neuroimaging changes.
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Affiliation(s)
- Won Jong Chwa
- Saint Louis University School of Medicine, St. Louis, MO, USA
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
| | - Oscar L. Lopez
- University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - W.T. Longstreth
- Departments of Neurology and Epidemiology, University of Washington, Seattle, WA, USA
| | - Weiying Dai
- Department of Computer Science, State University of New York at Binghamton, Binghamton, NY, USA
| | - Cyrus A. Raji
- Mallinckrodt Institute of Radiology, Washington University School of Medicine, St. Louis, MO, USA
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4
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Luquez T, Gaur P, Kosater IM, Lam M, Lee DI, Mares J, Paryani F, Yadav A, Menon V. Cell type-specific changes identified by single-cell transcriptomics in Alzheimer's disease. Genome Med 2022; 14:136. [PMID: 36447241 PMCID: PMC9710120 DOI: 10.1186/s13073-022-01136-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Accepted: 11/07/2022] [Indexed: 12/05/2022] Open
Abstract
The rapid advancement of single-cell transcriptomics in neurology has allowed for profiling of post-mortem human brain tissue across multiple diseases. Over the past 3 years, several studies have examined tissue from donors with and without diagnoses of Alzheimer's disease, highlighting key changes in cell type composition and molecular signatures associated with pathology and, in some cases, cognitive decline. Although all of these studies have generated single-cell/nucleus RNA-seq or ATAC-seq data from the full array of major cell classes in the brain, they have each focused on changes in specific cell types. Here, we synthesize the main findings from these studies and contextualize them in the overall space of large-scale omics studies of Alzheimer's disease. Finally, we touch upon new horizons in the field, in particular advancements in high-resolution spatial interrogation of tissue and multi-modal efforts-and how they are likely to further advance mechanistic and target-selection studies on Alzheimer's disease.
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Affiliation(s)
- Tain Luquez
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Pallavi Gaur
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Ivy M Kosater
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Matti Lam
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Dylan I Lee
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Jason Mares
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Fahad Paryani
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Archana Yadav
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
| | - Vilas Menon
- grid.21729.3f0000000419368729Center for Translational & Computational Immunology, Department of Neurology and Taub Institute for Research on Alzheimer’s Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY USA
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5
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Holt AG, Davies AM. A comparison of mtDNA deletion mutant proliferation mechanisms. J Theor Biol 2022; 551-552:111244. [PMID: 35973607 DOI: 10.1016/j.jtbi.2022.111244] [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: 04/26/2022] [Revised: 07/17/2022] [Accepted: 08/08/2022] [Indexed: 11/18/2022]
Abstract
In this paper we use simulation methods to investigate the proliferation of deletion mutations of mitochondrial DNA in neurons. We simulate three mtDNA proliferation mechanisms, namely, random drift, replicative advantage and vicious cycle. For each mechanism, we investigated the effect mutation rates have on neuron loss within a human host. We also compare heteroplasmy of each mechanism at mutation rates that yield the levels neuron loss that would be associated with dementia. Both random drift and vicious cycle predicted high levels of heteroplasmy, while replicative advantage showed a small number of dominant clones with a low background of heteroplasmy.
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6
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Pogue AI, Jaber VR, Sharfman NM, Zhao Y, Lukiw WJ. Downregulation of Neurofilament Light Chain Expression in Human Neuronal-Glial Cell Co-Cultures by a Microbiome-Derived Lipopolysaccharide-Induced miRNA-30b-5p. Front Neurol 2022; 13:900048. [PMID: 35812116 PMCID: PMC9263091 DOI: 10.3389/fneur.2022.900048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 05/12/2022] [Indexed: 11/26/2022] Open
Abstract
Microbiome-derived Gram-negative bacterial lipopolysaccharide (LPS) has been shown by multiple laboratories to reside within Alzheimer's disease (AD)-affected neocortical and hippocampal neurons. LPS and other pro-inflammatory stressors strongly induce a defined set of NF-kB (p50/p65)-sensitive human microRNAs, including a brain-enriched Homo sapien microRNA-30b-5p (hsa-miRNA-30b-5p; miRNA-30b). Here we provide evidence that this neuropathology-associated miRNA, known to be upregulated in AD brain and LPS-stressed human neuronal-glial (HNG) cells in primary culture targets the neurofilament light (NF-L) chain mRNA 3'-untranslated region (3'-UTR), which is conducive to the post-transcriptional downregulation of NF-L expression observed within both AD and LPS-treated HNG cells. A deficiency of NF-L is associated with consequent atrophy of the neuronal cytoskeleton and the disruption of synaptic organization. Interestingly, miRNA-30b has previously been shown to be highly expressed in amyloid-beta (Aβ) peptide-treated animal and cell models, and Aβ peptides promote LPS entry into neurons. Increased miRNA-30b expression induces neuronal injury, neuron loss, neuronal inflammation, impairment of synaptic transmission, and synaptic failure in neurodegenerative disease and transgenic murine models. This gut microbiota-derived LPS-NF-kB-miRNA-30b-NF-L pathological signaling network: (i) underscores a positive pathological link between the LPS of gastrointestinal (GI)-tract microbes and the inflammatory neuropathology, disordered cytoskeleton, and disrupted synaptic signaling of the AD brain and stressed brain cells; and (ii) is the first example of a microbiome-derived neurotoxic glycolipid having significant detrimental miRNA-30b-mediated actions on the expression of NF-L, an abundant neuron-specific filament protein known to be important in the maintenance of neuronal cell shape, axonal caliber, and synaptic homeostasis.
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Affiliation(s)
| | - Vivian R. Jaber
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA, United States
| | - Nathan M. Sharfman
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA, United States
| | - Yuhai Zhao
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA, United States
- Department of Cell Biology and Anatomy, Louisiana State University Health Science Center, New Orleans, LA, United States
| | - Walter J. Lukiw
- Alchem Biotech Research, Toronto, ON, Canada
- LSU Neuroscience Center, Louisiana State University Health Science Center, New Orleans, LA, United States
- Department of Ophthalmology, Louisiana State University Health Science Center, New Orleans, LA, United States
- Department Neurology, Louisiana State University Health Science Center, New Orleans, LA, United States
- *Correspondence: Walter J. Lukiw
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7
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Konno D, Ikegaya Y, Sasaki T. Weak representation of awake/sleep states by local field potentials in aged mice. Sci Rep 2022; 12:7766. [PMID: 35545694 PMCID: PMC9095686 DOI: 10.1038/s41598-022-11888-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Accepted: 05/03/2022] [Indexed: 11/19/2022] Open
Abstract
Senescence affects various aspects of sleep, and it remains unclear how sleep-related neuronal network activity is altered by senescence. Here, we recorded local field potential signals from multiple brain regions covering the forebrain in young (10-week-old) and aged (2-year-old) mice. Interregional LFP correlations across these brain regions could not detect pronounced differences between awake and sleep states in both young and aged mice. Multivariate analyses with machine learning algorithms with uniform manifold approximation and projection and robust continuous clustering demonstrated that LFP correlational patterns at multiple frequency bands, ranging from delta to high gamma bands, in aged mice less represented awake/sleep states than those in young mice. By housing aged mice in an enriched environment, the LFP patterns were changed to more precisely represent awake/sleep states. Our results demonstrate senescence-induced changes in neuronal activity at the network level and provide insight into the prevention of pathological symptoms associated with sleep disturbance in senescence.
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Affiliation(s)
- Daichi Konno
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.,Laboratory of Geriatric Medicine, Graduate School of Medicine, The University of Tokyo, Tokyo, 113-0033, Japan
| | - Yuji Ikegaya
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan.,Institute for AI and Beyond, The University of Tokyo, Tokyo, 113-0033, Japan.,Center for Information and Neural Networks, National Institute of Information and Communications Technology, Suita City, Osaka, 565-0871, Japan
| | - Takuya Sasaki
- Laboratory of Chemical Pharmacology, Graduate School of Pharmaceutical Sciences, The University of Tokyo, Tokyo, 113-0033, Japan. .,Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aramaki-Aoba, Aoba-Ku, Sendai, 980-8578, Japan.
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8
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Chen S, Acosta D, Li L, Liang J, Chang Y, Wang C, Fitzgerald J, Morrison C, Goulbourne CN, Nakano Y, Villegas NCH, Venkataraman L, Brown C, Serrano GE, Bell E, Wemlinger T, Wu M, Kokiko-Cochran ON, Popovich P, Flowers XE, Honig LS, Vonsattel JP, Scharre DW, Beach TG, Ma Q, Kuret J, Kõks S, Urano F, Duff KE, Fu H. Wolframin is a novel regulator of tau pathology and neurodegeneration. Acta Neuropathol 2022; 143:547-569. [PMID: 35389045 DOI: 10.1007/s00401-022-02417-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2021] [Revised: 03/30/2022] [Accepted: 03/31/2022] [Indexed: 12/17/2022]
Abstract
Selective neuronal vulnerability to protein aggregation is found in many neurodegenerative diseases including Alzheimer's disease (AD). Understanding the molecular origins of this selective vulnerability is, therefore, of fundamental importance. Tau protein aggregates have been found in Wolframin (WFS1)-expressing excitatory neurons in the entorhinal cortex, one of the earliest affected regions in AD. The role of WFS1 in Tauopathies and its levels in tau pathology-associated neurodegeneration, however, is largely unknown. Here we report that WFS1 deficiency is associated with increased tau pathology and neurodegeneration, whereas overexpression of WFS1 reduces those changes. We also find that WFS1 interacts with tau protein and controls the susceptibility to tau pathology. Furthermore, chronic ER stress and autophagy-lysosome pathway (ALP)-associated genes are enriched in WFS1-high excitatory neurons in human AD at early Braak stages. The protein levels of ER stress and autophagy-lysosome pathway (ALP)-associated proteins are changed in tau transgenic mice with WFS1 deficiency, while overexpression of WFS1 reverses those changes. This work demonstrates a possible role for WFS1 in the regulation of tau pathology and neurodegeneration via chronic ER stress and the downstream ALP. Our findings provide insights into mechanisms that underpin selective neuronal vulnerability, and for developing new therapeutics to protect vulnerable neurons in AD.
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9
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Ma L, Tian L, Hu T, Jiang T, Zuo N. Development of Individual Variability in Brain Functional Connectivity and Capability across the Adult Lifespan. Cereb Cortex 2021; 31:3925-3938. [PMID: 33822909 DOI: 10.1093/cercor/bhab059] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 01/26/2021] [Accepted: 02/07/2021] [Indexed: 11/14/2022] Open
Abstract
Individual variability exists in both brain function and behavioral performance. However, changes in individual variability in brain functional connectivity and capability across adult development and aging have not yet been clearly examined. Based on resting-state functional magnetic resonance imaging data from a large cohort of participants (543 adults, aged 18-88 years), brain functional connectivity was analyzed to characterize the spatial distribution and differences in individual variability across the adult lifespan. Results showed high individual variability in the association cortex over the adult lifespan, whereas individual variability in the primary cortex was comparably lower in the initial stage but increased with age. Individual variability was also negatively correlated with the strength/number of short-, medium-, and long-range functional connections in the brain, with long-range connections playing a more critical role in increasing global individual variability in the aging brain. More importantly, in regard to specific brain regions, individual variability in the motor cortex was significantly correlated with differences in motor capability. Overall, we identified specific patterns of individual variability in brain functional structure during the adult lifespan and demonstrated that functional variability in the brain can reflect behavioral performance. These findings advance our understanding of the underlying principles of the aging brain across the adult lifespan and suggest how to characterize degenerating behavioral capability using imaging biomarkers.
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Affiliation(s)
- Liying Ma
- School of Computer and Information Technology, Beijing Jiaotong University, Beijing 100044, China.,Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China
| | - Lixia Tian
- School of Computer and Information Technology, Beijing Jiaotong University, Beijing 100044, China
| | - Tianyu Hu
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100190, China
| | - Tianzi Jiang
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100190, China.,Chinese Institute for Brain Research, Beijing 102206, China.,CAS Center for Excellence in Brain Science and Intelligence Technology, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,Key Laboratory for Neuro-Information of the Ministry of Education, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 625014, China.,Queensland Brain Institute, University of Queensland, Brisbane, QLD 4072, Australia
| | - Nianming Zuo
- Brainnetome Center, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,National Laboratory of Pattern Recognition, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,University of Chinese Academy of Sciences, Beijing 100190, China.,Chinese Institute for Brain Research, Beijing 102206, China
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10
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Matthews DC, Mao X, Dowd K, Tsakanikas D, Jiang CS, Meuser C, Andrews RD, Lukic AS, Lee J, Hampilos N, Shafiian N, Sano M, David Mozley P, Fillit H, McEwen BS, Shungu DC, Pereira AC. Riluzole, a glutamate modulator, slows cerebral glucose metabolism decline in patients with Alzheimer's disease. Brain 2021; 144:3742-3755. [PMID: 34145880 DOI: 10.1093/brain/awab222] [Citation(s) in RCA: 43] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 04/07/2021] [Accepted: 05/22/2021] [Indexed: 11/14/2022] Open
Abstract
Dysregulation of glutamatergic neural circuits has been implicated in a cycle of toxicity, believed among the neurobiological underpinning of Alzheimer's disease. Previously, we reported preclinical evidence that the glutamate modulator riluzole, which is FDA-approved for the treatment of amyotrophic lateral sclerosis, has potential benefits on cognition, structural and molecular markers of aging and Alzheimer's disease. The objective of this study was to evaluate in a pilot clinical trial, using neuroimaging biomarkers, the potential efficacy and safety of riluzole in patients with Alzheimer's disease as compared to placebo. A 6-month phase 2 double-blind, randomized, placebo-controlled study was conducted at two sites. Participants consisted of males and females, 50 to 95 years of age, with a clinical diagnosis of probable Alzheimer's disease, and Mini-Mental State Examination between 19 and 27. Ninety-four participants were screened, fifty subjects that met inclusion criteria were randomly assigned to receive 50 mg riluzole (n = 26) or placebo (n = 24) twice a day. Twenty-two riluzole-treated and 20 placebo participants completed the study. Primary endpoints were baseline to 6 months changes in a) cerebral glucose metabolism as measured with fluorodeoxyglucose-positron emission tomography in pre-specified regions of interest (hippocampus, posterior cingulate, precuneus, lateral temporal, inferior parietal, frontal) and b) changes in posterior cingulate levels of the neuronal viability marker N-acetylaspartate as measured with in vivo proton magnetic resonance spectroscopy. Secondary outcome measures were neuropsychological testing for correlation with neuroimaging biomarkers and in vivo measures of glutamate in posterior cingulate measured with magnetic resonance spectroscopy as a potential marker of target engagement. Measures of cerebral glucose metabolism, a well-established Alzheimer's disease biomarker and predictor of disease progression, declined significantly less in several pre-specified regions of interest with the most robust effect in posterior cingulate, and effects in precuneus, lateral temporal, right hippocampus and frontal cortex in riluzole-treated subjects in comparison to placebo group. No group effect was found in measures of N-acetylaspartate levels. A positive correlation was observed between cognitive measures and regional cerebral glucose metabolism. A group by visit interaction was observed in glutamate levels in posterior cingulate, potentially suggesting engagement of glutamatergic system by riluzole. In vivo glutamate levels positively correlated with cognitive performance. These findings support our main primary hypothesis that cerebral glucose metabolism would be better preserved in the riluzole treated group than in the placebo group and investigations in future larger and longer studies to test riluzole as a potential novel therapeutic intervention for Alzheimer's disease.
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Affiliation(s)
| | - Xiangling Mao
- Department of Radiology, Weill Cornell Medicine, New York, NY, 10021 USA
| | | | | | | | - Caroline Meuser
- Department of Psychiatry, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029 USA
| | | | - Ana S Lukic
- ADM Diagnostics Inc., Northbrook, IL, 60062 USA
| | - Jihyun Lee
- Department of Radiology, Weill Cornell Medicine, New York, NY, 10021 USA
| | - Nicholas Hampilos
- Department of Radiology, Weill Cornell Medicine, New York, NY, 10021 USA
| | - Neeva Shafiian
- Department of Neurology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029 USA.,Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029 USA
| | - Mary Sano
- Department of Psychiatry, Alzheimer's Disease Research Center, Icahn School of Medicine at Mount Sinai, New York, NY, 10029 USA
| | - P David Mozley
- Department of Radiology, Weill Cornell Medicine, New York, NY, 10021 USA
| | - Howard Fillit
- Alzheimer's Drug Discovery Foundation, New York, NY, 10019 USA
| | | | - Dikoma C Shungu
- Department of Radiology, Weill Cornell Medicine, New York, NY, 10021 USA
| | - Ana C Pereira
- The Rockefeller University, New York, NY, 10065 USA.,Department of Neurology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029 USA.,Nash Family Department of Neuroscience, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029 USA.,Ronald M. Loeb Center for Alzheimer's Disease, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
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11
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Panagiotou M, Michel S, Meijer JH, Deboer T. The aging brain: sleep, the circadian clock and exercise. Biochem Pharmacol 2021; 191:114563. [PMID: 33857490 DOI: 10.1016/j.bcp.2021.114563] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2021] [Revised: 04/06/2021] [Accepted: 04/07/2021] [Indexed: 12/26/2022]
Abstract
Aging is a multifactorial process likely stemming from damage accumulation and/or a decline in maintenance and repair mechanisms in the organisms that eventually determine their lifespan. In our review, we focus on the morphological and functional alterations that the aging brain undergoes affecting sleep and the circadian clock in both human and rodent models. Although both species share mammalian features, differences have been identified on several experimental levels, which we outline in this review. Additionally, we delineate some challenges on the preferred analysis and we suggest that a uniform route is followed so that findings can be smoothly compared. We conclude by discussing potential interventions and highlight the influence of physical exercise as a beneficial lifestyle intervention, and its effect on healthy aging and longevity. We emphasize that even moderate age-matched exercise is able to ameliorate several aging characteristics as far as sleep and circadian rhythms are concerned, independent of the species studied.
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Affiliation(s)
- M Panagiotou
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands.
| | - S Michel
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands
| | - J H Meijer
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands
| | - T Deboer
- Laboratory for Neurophysiology, Department of Cell and Chemical Biology, Leiden University Medical Center, The Netherlands
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12
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Galvin VC, Yang ST, Paspalas CD, Yang Y, Jin LE, Datta D, Morozov YM, Lightbourne TC, Lowet AS, Rakic P, Arnsten AFT, Wang M. Muscarinic M1 Receptors Modulate Working Memory Performance and Activity via KCNQ Potassium Channels in the Primate Prefrontal Cortex. Neuron 2020; 106:649-661.e4. [PMID: 32197063 DOI: 10.1016/j.neuron.2020.02.030] [Citation(s) in RCA: 46] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2019] [Revised: 01/21/2020] [Accepted: 02/25/2020] [Indexed: 02/06/2023]
Abstract
Working memory relies on the dorsolateral prefrontal cortex (dlPFC), where microcircuits of pyramidal neurons enable persistent firing in the absence of sensory input, maintaining information through recurrent excitation. This activity relies on acetylcholine, although the molecular mechanisms for this dependence are not thoroughly understood. This study investigated the role of muscarinic M1 receptors (M1Rs) in the dlPFC using iontophoresis coupled with single-unit recordings from aging monkeys with naturally occurring cholinergic depletion. We found that M1R stimulation produced an inverted-U dose response on cell firing and behavioral performance when given systemically to aged monkeys. Immunoelectron microscopy localized KCNQ isoforms (Kv7.2, Kv7.3, and Kv7.5) on layer III dendrites and spines, similar to M1Rs. Iontophoretic manipulation of KCNQ channels altered cell firing and reversed the effects of M1R compounds, suggesting that KCNQ channels are one mechanism for M1R actions in the dlPFC. These results indicate that M1Rs may be an appropriate target to treat cognitive disorders with cholinergic alterations.
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Affiliation(s)
- Veronica C Galvin
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Sheng Tao Yang
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | | | - Yang Yang
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Lu E Jin
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Dibyadeep Datta
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Yury M Morozov
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Taber C Lightbourne
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Adam S Lowet
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Pasko Rakic
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Amy F T Arnsten
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA
| | - Min Wang
- Department of Neuroscience, Yale University School of Medicine, New Haven, CT 06520, USA.
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13
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Abstract
The prefrontal cortex underlies our high order cognitive abilities and is the target of projections from many neuromodulatory nuclei. The dorsolateral prefrontal cortex is particularly critical for rule representation and working memory, or the ability to hold information "in mind" in the absence of sensory input. Emerging evidence supports a prominent and permissive role for acetylcholine in these excitatory circuits, through actions at cholinergic nicotinic receptors. Here we review the involvement of acetylcholine in working memory via actions at nicotinic receptors.
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14
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Oligomeric Aβ in the monkey brain impacts synaptic integrity and induces accelerated cortical aging. Proc Natl Acad Sci U S A 2019; 116:26239-26246. [PMID: 31871145 DOI: 10.1073/pnas.1902301116] [Citation(s) in RCA: 60] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
As the average age of the population continues to rise, the number of individuals affected with age-related cognitive decline and Alzheimer's disease (AD) has increased and is projected to cost more than $290 billion in the United States in 2019. Despite significant investment in research over the last decades, there is no effective treatment to prevent or delay AD progression. There is a translational gap in AD research, with promising drugs based on work in rodent models failing in clinical trials. Aging is the leading risk factor for developing AD and understanding neurobiological changes that affect synaptic integrity with aging will help clarify why the aged brain is vulnerable to AD. We describe here the development of a rhesus monkey model of AD using soluble oligomers of the amyloid beta (Aβ) peptide (AβOs). AβOs infused into the monkey brain target a specific population of spines in the prefrontal cortex, induce neuroinflammation, and increase AD biomarkers in the cerebrospinal fluid to similar levels observed in patients with AD. Importantly, AβOs lead to similar dendritic spine loss to that observed in normal aging in monkeys, but so far without detection of amyloid plaques or tau pathology. Understanding the basis of synaptic impairment is the most effective route to early intervention and prevention or postponement of age-related cognitive decline and transition to AD. These initial findings support the use of monkeys as a platform to understand age-related vulnerabilities of the primate brain and may help develop effective disease-modifying therapies for treatment of AD and related dementias.
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15
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Sharma A, Kazim SF, Larson CS, Ramakrishnan A, Gray JD, McEwen BS, Rosenberg PA, Shen L, Pereira AC. Divergent roles of astrocytic versus neuronal EAAT2 deficiency on cognition and overlap with aging and Alzheimer's molecular signatures. Proc Natl Acad Sci U S A 2019; 116:21800-21811. [PMID: 31591195 PMCID: PMC6815169 DOI: 10.1073/pnas.1903566116] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
The excitatory amino acid transporter 2 (EAAT2) is the major glutamate transporter in the brain expressed predominantly in astrocytes and at low levels in neurons and axonal terminals. EAAT2 expression is reduced in aging and sporadic Alzheimer's disease (AD) patients' brains. The role EAAT2 plays in cognitive aging and its associated mechanisms remains largely unknown. Here, we show that conditional deletion of astrocytic and neuronal EAAT2 results in age-related cognitive deficits. Astrocytic, but not neuronal EAAT2, deletion leads to early deficits in short-term memory and in spatial reference learning and long-term memory. Neuronal EAAT2 loss results in late-onset spatial reference long-term memory deficit. Neuronal EAAT2 deletion leads to dysregulation of the kynurenine pathway, and astrocytic EAAT2 deficiency results in dysfunction of innate and adaptive immune pathways, which correlate with cognitive decline. Astrocytic EAAT2 deficiency also shows transcriptomic overlaps with human aging and AD. Overall, the present study shows that in addition to the widely recognized astrocytic EAAT2, neuronal EAAT2 plays a role in hippocampus-dependent memory. Furthermore, the gene expression profiles associated with astrocytic and neuronal EAAT2 deletion are substantially different, with the former associated with inflammation and synaptic function similar to changes observed in human AD and gene expression changes associated with inflammation similar to the aging human brain.
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Affiliation(s)
- Abhijeet Sharma
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Syed Faraz Kazim
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Chloe S Larson
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065
| | - Aarthi Ramakrishnan
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Jason D Gray
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065
| | - Bruce S McEwen
- Laboratory of Neuroendocrinology, The Rockefeller University, New York, NY 10065;
| | - Paul A Rosenberg
- Department of Neurology and the F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115
- Program in Neuroscience, Harvard Medical School, Boston, MA 02115
| | - Li Shen
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
| | - Ana C Pereira
- Department of Neurology, Icahn School of Medicine at Mount Sinai, New York, NY 10029;
- Fishberg Department of Neuroscience, Icahn School of Medicine at Mount Sinai, New York, NY 10029
- Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029
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16
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Sessle BJ. Can you be too old for oral implants? An update on ageing and plasticity in the oro‐facial sensorimotor system. J Oral Rehabil 2019; 46:936-951. [DOI: 10.1111/joor.12830] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2019] [Revised: 05/06/2019] [Accepted: 05/26/2019] [Indexed: 12/24/2022]
Affiliation(s)
- Barry J. Sessle
- Faculty of Dentistry University of Toronto Toronto Ontario Canada
- Department of Physiology, Faculty of Medicine University of Toronto Toronto Ontario Canada
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17
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Lupo G, Gaetani S, Cacci E, Biagioni S, Negri R. Molecular Signatures of the Aging Brain: Finding the Links Between Genes and Phenotypes. Neurotherapeutics 2019; 16:543-553. [PMID: 31161490 PMCID: PMC6694319 DOI: 10.1007/s13311-019-00743-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Aging is associated with cognitive decline and increased vulnerability to neurodegenerative diseases. The progressive extension of the average human lifespan is bound to lead to a corresponding increase in the fraction of cognitively impaired elderly individuals among the human population, with an enormous societal and economic burden. At the cellular and tissue levels, cognitive decline is linked to a reduction in specific neuronal subpopulations, a widespread decrease in synaptic plasticity and an increase in neuroinflammation due to an enhanced activation of astrocytes and microglia, but the molecular mechanisms underlying these functional changes during normal aging and in neuropathological conditions remain poorly understood. In this review, we summarize very recent and outstanding progress in elucidating the molecular changes associated with cognitive decline through the genome-wide profiling of aging brain cells at different molecular levels (genomic, epigenomic, transcriptomic, proteomic). We discuss how the correlation of different molecular and phenotypic traits driven by mathematical and computational analyses of large datasets has led to the prediction of key molecular nodes of neurodegenerative pathways, and provide a few examples of candidate regulators of cognitive decline identified with these approaches. Furthermore, we highlight the dysregulation of the synaptic transcriptome in neuronal cells and of the inflammatory transcriptome in glial cells as some of the key events during normal and neuropathological human brain aging.
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Affiliation(s)
- Giuseppe Lupo
- Department of Chemistry, Sapienza University of Rome, Piazzale A. Moro, 00185, Rome, Italy.
| | - Silvana Gaetani
- Department of Physiology and Farmacology "V. Erspamer", Sapienza University of Rome, Piazzale A. Moro, 00185, Rome, Italy
| | - Emanuele Cacci
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Piazzale A. Moro, 00185, Rome, Italy
| | - Stefano Biagioni
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Piazzale A. Moro, 00185, Rome, Italy
| | - Rodolfo Negri
- Department of Biology and Biotechnology "C. Darwin", Sapienza University of Rome, Piazzale A. Moro, 00185, Rome, Italy
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18
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Abstract
All people want to age "successfully," maintaining functional capacity and quality of life as they reach advanced age. Achieving this goal depends on preserving optimal cognitive and brain functioning. Yet, significant individual differences exist in this regard. Some older adults continue to retain most cognitive abilities throughout their lifetime. Others experience declines in cognitive and functional capacity that range from mild decrements in certain cognitive functions over time to severe dementia among those with neurodegenerative diseases. Even among relatively healthy "successful agers," certain cognitive functions are reduced from earlier levels. This is particularly true for cognitive functions that are dependent on cognitive processing speed and efficiency. Working memory and executive and attentional functions tend to be most vulnerable. Learning and memory functions are also usually reduced, although in the absence of neurodegenerative disease learning and retrieval efficiency rather than memory storage are affected. Other functions, such as visual perception, language, semantics, and knowledge, are often well preserved. Structural, functional, and physiologic/metabolic brain changes correspond with age-associated cognitive decline. Physiologic and metabolic mechanisms, such as oxidative stress and neuroinflammation, may contribute to these changes, along with the contribution of comorbidities that secondarily affect the brain of older adults. Cognitive frailty often corresponds with physical frailty, both affected by multiple exogenous and endogenous factors. Neuropsychologic assessment provides a way of measuring the cognitive and functional status of older adults, which is useful for monitoring changes that may be occurring. Neuroimaging is also useful for characterizing age-associated structural, functional, physiologic, and metabolic brain changes, including alterations in cerebral blood flow and metabolite concentrations. Some interventions that may enhance cognitive function, such as cognitive training, neuromodulation, and pharmacologic approaches, exist or are being developed. Yet, preventing, slowing, and reversing the adverse effects of cognitive aging remains a challenge.
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Affiliation(s)
- Ronald A Cohen
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States.
| | - Michael M Marsiske
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States
| | - Glenn E Smith
- Center for Cognitive Aging and Memory, McKnight Brain Institute, University of Florida, Gainesville, FL, United States; Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, United States
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19
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Shah-Basak PP, Kielar A, Deschamps T, Verhoeff NP, Jokel R, Meltzer J. Spontaneous oscillatory markers of cognitive status in two forms of dementia. Hum Brain Mapp 2018; 40:1594-1607. [PMID: 30421472 DOI: 10.1002/hbm.24470] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 10/09/2018] [Accepted: 11/01/2018] [Indexed: 01/23/2023] Open
Abstract
Abnormal oscillatory brain activity in dementia may indicate incipient neuronal/synaptic dysfunction, rather than frank structural atrophy. Leveraging a potential link between the degree of abnormal oscillatory activity and cognitive symptom severity, one could localize brain regions in a diseased but pre-atrophic state, which may be more amenable to interventions. In the current study, we evaluated the relationships among cognitive deficits, regional volumetric changes, and resting-state magnetoencephalography abnormalities in patients with mild cognitive impairment (MCI; N = 10; age: 75.9 ± 7.3) or primary progressive aphasia (PPA; N = 12; 69.7 ± 8.0), and compared them to normal aging [young (N = 18; 24.6 ± 3.5), older controls (N = 24; 67.2 ± 9.7]. Whole-brain source-level resting-state estimates of relative oscillatory power in the delta (1-4 Hz), theta (4-7 Hz), alpha (8-12 Hz), and beta (15-30 Hz) bands were combined with gray matter volumes and cognitive scores to examine between-group differences and brain-behavior correlations. Language and executive function (EF) abilities were impaired in patients with PPA, while episodic memory was impaired in MCI. Widespread oscillatory speeding and volumetric shrinkage was associated with normal aging, whereas the trajectory in PPA indicated widespread oscillatory slowing with additional volumetric reductions. Increases in delta and decreases in alpha power uniquely predicted group membership to PPA. Beyond volumetric reductions, more delta predicted poorer memory. In patients with MCI, no consistent group difference among oscillatory measures was found. The contributions of delta/alpha power on memory abilities were larger than volumetric differences. Spontaneous oscillatory abnormalities in association with cognitive symptom severity can serve as a marker of neuronal dysfunction in dementia, providing targets for promising treatments.
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Affiliation(s)
- Priyanka P Shah-Basak
- Rotman Research Institute, Baycrest Health Sciences Centre, Toronto, Ontario, Canada.,Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada
| | - Aneta Kielar
- Rotman Research Institute, Baycrest Health Sciences Centre, Toronto, Ontario, Canada.,Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada.,Department of Speech, Language, and Hearing Sciences, University of Arizona, Tucson, Arizona
| | - Tiffany Deschamps
- Rotman Research Institute, Baycrest Health Sciences Centre, Toronto, Ontario, Canada
| | - Nicolaas Paul Verhoeff
- Department of Psychiatry, University of Toronto, Toronto, Ontario, Canada.,Department of Psychiatry, Baycrest Health Sciences, North York, Ontario, Canada
| | - Regina Jokel
- Rotman Research Institute, Baycrest Health Sciences Centre, Toronto, Ontario, Canada.,Department of Psychiatry, Baycrest Health Sciences, North York, Ontario, Canada.,Department of Speech-Language Pathology, University of Toronto, Toronto, Ontario, Canada
| | - Jed Meltzer
- Rotman Research Institute, Baycrest Health Sciences Centre, Toronto, Ontario, Canada.,Canadian Partnership for Stroke Recovery, Ottawa, Ontario, Canada.,Department of Speech-Language Pathology, University of Toronto, Toronto, Ontario, Canada.,Department of Psychology, University of Toronto, Toronto, Ontario, Canada
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20
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Ivanova GP, Gorobets LN, Litvinov AV, Bulanov VS, Vasilenko LM. [A role of progesterone and its metabolites in regulation functions of the brain]. Zh Nevrol Psikhiatr Im S S Korsakova 2018; 118:129-137. [PMID: 29927417 DOI: 10.17116/jnevro201811851129] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The review presents literature data reflecting the nature and mechanism of the effect of progesterone and its metabolites on human and animal brain structures. Particular attention is paid to neuroprotective, anticonvulsant, anti-anxiety and sedative properties of this hormone, which determines the prospect of its use for the prevention and treatment of human neurodegenerative diseases, epilepsy, sleep disorders, and anxiety-depressive spectrum disorders, including premenstrual and climacteric syndromes.
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Affiliation(s)
- G P Ivanova
- Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow, Russia
| | - L N Gorobets
- Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow, Russia
| | - A V Litvinov
- Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow, Russia
| | - V S Bulanov
- Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow, Russia
| | - L M Vasilenko
- Serbsky National Medical Research Center for Psychiatry and Narcology, Moscow, Russia
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21
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Neuroprotective Effects of Macrovipera lebetina Snake Venom in the Model of Alzheimer’s Disease. NEUROPHYSIOLOGY+ 2018. [DOI: 10.1007/s11062-018-9704-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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22
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Lee A, Shen M, Qiu A. Psychiatric polygenic risk associates with cortical morphology and functional organization in aging. Transl Psychiatry 2017; 7:1276. [PMID: 29225336 PMCID: PMC5802582 DOI: 10.1038/s41398-017-0036-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 08/04/2017] [Accepted: 09/07/2017] [Indexed: 01/23/2023] Open
Abstract
Common brain abnormalities in cortical morphology and functional organization are observed in psychiatric disorders and aging, reflecting shared genetic influences. This preliminary study aimed to examine the contribution of a polygenetic risk for psychiatric disorders (PRScross) to aging brain and to identify molecular mechanisms through the use of multimodal brain images, genotypes, and transcriptome data. We showed age-related cortical thinning in bilateral inferior frontal cortex (IFC) and superior temporal gyrus and alterations in the functional connectivity between bilateral IFC and between right IFC and right inferior parietal lobe as a function of PRScross. Interestingly, the genes in PRScross, that contributed most to aging neurodegeneration, were expressed in the functioanlly connected cortical regions. Especially, genes identified through the genotype-functional connectivity association analysis were commonly expressed in both cortical regions and formed strong gene networks with biological processes related to neural plasticity and synaptogenesis, regulated by glutamatergic and GABAergic transmission, neurotrophin signaling, and metabolism. This study suggested integrating genotype and transcriptome with neuroimage data sheds new light on the mechanisms of aging brain.
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Affiliation(s)
- Annie Lee
- 0000 0001 2180 6431grid.4280.eDepartment of Biomedical Engineering, National University of Singapore, Singapore, 117576 Singapore
| | - Mojun Shen
- 0000 0004 0637 0221grid.185448.4Singapore Institute for Clinical Sciences, The Agency for Science, Technology and Research, Singapore, 117609 Singapore
| | - Anqi Qiu
- Department of Biomedical Engineering, National University of Singapore, Singapore, 117576, Singapore. .,Singapore Institute for Clinical Sciences, The Agency for Science, Technology and Research, Singapore, 117609, Singapore. .,Clinical Imaging Research Center, National University of Singapore, Singapore, 117456, Singapore.
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23
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Avivi-Arber L, Sessle BJ. Jaw sensorimotor control in healthy adults and effects of ageing. J Oral Rehabil 2017; 45:50-80. [DOI: 10.1111/joor.12554] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2017] [Indexed: 12/22/2022]
Affiliation(s)
- L. Avivi-Arber
- Faculty of Dentistry; University of Toronto; Toronto ON Canada
| | - B. J. Sessle
- Faculty of Dentistry; University of Toronto; Toronto ON Canada
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24
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Directed Functional Networks in Alzheimer's Disease: Disruption of Global and Local Connectivity Measures. IEEE J Biomed Health Inform 2017; 21:949-955. [DOI: 10.1109/jbhi.2016.2578954] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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25
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Andreeva TV, Lukiw WJ, Rogaev EI. Biological Basis for Amyloidogenesis in Alzheimer's Disease. BIOCHEMISTRY (MOSCOW) 2017; 82:122-139. [PMID: 28320296 DOI: 10.1134/s0006297917020043] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Certain cellular proteins normally soluble in the living organism under certain conditions form aggregates with a specific cross-β sheet structure called amyloid. These intra- or extracellular insoluble aggregates (fibers or plaques) are hallmarks of many neurodegenerative pathologies including Alzheimer's disease (AD), Huntington's disease, Parkinson's disease, prion disease, and other progressive neurological diseases that develop in the aging human central nervous system. Amyloid diseases (amyloidoses) are widespread in the elderly human population, a rapidly expanding demographic in many global populations. Increasing age is the most significant risk factor for neurodegenerative diseases associated with amyloid plaques. To date, nearly three dozen different misfolded proteins targeting brain and other organs have been identified in amyloid diseases and AD, the most prevalent neurodegenerative amyloid disease affecting over 15 million people worldwide. Here we (i) highlight the latest data on mechanisms of amyloid formation and further discuss a hypothesis on the amyloid cascade as a primary mechanism of AD pathogenesis and (ii) review the evolutionary aspects of amyloidosis, which allow new insight on human-specific mechanisms of dementia development.
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Affiliation(s)
- T V Andreeva
- Vavilov Institute of General Genetics, Russian Academy of Sciences, Moscow, 119991, Russia.
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26
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Cellular Deconstruction: Finding Meaning in Individual Cell Variation. Trends Cell Biol 2016; 25:569-578. [PMID: 26410403 DOI: 10.1016/j.tcb.2015.07.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Revised: 06/26/2015] [Accepted: 07/17/2015] [Indexed: 12/21/2022]
Abstract
The advent of single cell transcriptome analysis has permitted the discovery of cell-to-cell variation in transcriptome expression of even presumptively identical cells. We hypothesize that this variability reflects a many-to-one relation between transcriptome states and the phenotype of a cell. In this relation, the molecular ratios of the subsets of RNA are determined by the stoichiometric constraints of the cell systems, which underdetermine the transcriptome state. Furthermore, the variability is, in part, induced by the tissue context and is important for system-level function. This theory is analogous to theories of literary deconstruction, where multiple 'signifiers' work in opposition to one another to create meaning. By analogy, transcriptome phenotypes should be defined as subsets of RNAs comprising selected RNA systems where the system-associated RNAs are balanced with each other to produce the associated cellular function. This idea provides a framework for understanding cellular heterogeneity in phenotypic responses to variant conditions, such as disease challenge.
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27
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Hamson DK, Roes MM, Galea LAM. Sex Hormones and Cognition: Neuroendocrine Influences on Memory and Learning. Compr Physiol 2016; 6:1295-337. [DOI: 10.1002/cphy.c150031] [Citation(s) in RCA: 118] [Impact Index Per Article: 14.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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28
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Chiarini A, Armato U, Liu D, Dal Prà I. Calcium-Sensing Receptors of Human Neural Cells Play Crucial Roles in Alzheimer's Disease. Front Physiol 2016; 7:134. [PMID: 27199760 PMCID: PMC4844916 DOI: 10.3389/fphys.2016.00134] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Accepted: 03/28/2016] [Indexed: 12/21/2022] Open
Abstract
In aged subjects, late-onset Alzheimer's disease (LOAD) starts in the lateral entorhinal allocortex where a failure of clearance mechanisms triggers an accumulation of neurotoxic amyloid-β42 oligomers (Aβ42-os). In neurons and astrocytes, Aβ42-os enhance the transcription of Aβ precursor protein (APP) and β-secretase/BACE1 genes. Thus, by acting together with γ-secretase, the surpluses of APP and BACE1 amplify the endogenous production of Aβ42-os which pile up, damage mitochondria, and are oversecreted. At the plasmalemma, exogenous Aβ42-os bind neurons' and astrocytes' calcium-sensing receptors (CaSRs) activating a set of intracellular signaling pathways which upkeep Aβ42-os intracellular accumulation and oversecretion by hindering Aβ42-os proteolysis. In addition, Aβ42-os accumulating in the extracellular milieu spread and reach mounting numbers of adjacent and remoter teams of neurons and astrocytes which in turn are recruited, again via Aβ42-os•CaSR-governed mechanisms, to produce and release additional Aβ42-os amounts. This relentless self-sustaining mechanism drives AD progression toward upper cortical areas. Later on accumulating Aβ42-os elicit the advent of hyperphosphorylated (p)-Tau oligomers which acting together with Aβ42-os and other glial neurotoxins cooperatively destroy wider and wider cognition-related cortical areas. In parallel, Aβ42-os•CaSR signals also elicit an excess production and secretion of nitric oxide and vascular endothelial growth factor-A from astrocytes, of Aβ42-os and myelin basic protein from oligodendrocytes, and of proinflammatory cytokines, nitric oxide and (likely) Aβ42-os from microglia. Activated astrocytes and microglia survive the toxic onslaught, whereas neurons and oligodendrocytes increasingly die. However, we have shown that highly selective allosteric CaSR antagonists (calcilytics), like NPS 2143 and NPS 89626, efficiently suppress all the neurotoxic effects Aβ42-os•CaSR signaling drives in cultured cortical untransformed human neurons and astrocytes. In fact, calcilytics increase Aβ42 proteolysis and discontinue the oversecretion of Aβ42-os, nitric oxide, and vascular endothelial growth factor-A from both astrocytes and neurons. Seemingly, calcilytics would also benefit the other types of glial cells and cerebrovascular cells otherwise damaged by the effects of Aβ42-os•CaSR signaling. Thus, given at amnestic minor cognitive impairment (aMCI) or initial symptomatic stages, calcilytics could prevent or terminate the propagation of LOAD neuropathology and preserve human neurons' viability and hence patients' cognitive abilities.
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Affiliation(s)
- Anna Chiarini
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
| | - Ubaldo Armato
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
| | - Daisong Liu
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
- Proteomics Laboratory, Institute for Burn Research, Third Military Medical UniversityChongqing, China
| | - Ilaria Dal Prà
- Human Histology and Embryology Unit, University of Verona Medical SchoolVerona, Italy
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Reversal of Aging-Related Neuronal Ca2+ Dysregulation and Cognitive Impairment by Delivery of a Transgene Encoding FK506-Binding Protein 12.6/1b to the Hippocampus. J Neurosci 2015. [PMID: 26224869 DOI: 10.1523/jneurosci.1248-15.2015] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
UNLABELLED Brain Ca2+ regulatory processes are altered during aging, disrupting neuronal, and cognitive functions. In hippocampal pyramidal neurons, the Ca2+ -dependent slow afterhyperpolarization (sAHP) exhibits an increase with aging, which correlates with memory impairment. The increased sAHP results from elevated L-type Ca2+ channel activity and ryanodine receptor (RyR)-mediated Ca2+ release, but underlying molecular mechanisms are poorly understood. Previously, we found that expression of the gene encoding FK506-binding protein 12.6/1b (FKBP1b), a small immunophilin that stabilizes RyR-mediated Ca2+ release in cardiomyocytes, declines in hippocampus of aged rats and Alzheimer's disease subjects. Additionally, knockdown/disruption of hippocampal FKBP1b in young rats augments neuronal Ca2+ responses. Here, we test the hypothesis that declining FKBP1b underlies aging-related hippocampal Ca2+ dysregulation. Using microinjection of adeno-associated viral vector bearing a transgene encoding FKBP1b into the hippocampus of aged male rats, we assessed the critical prediction that overexpressing FKBP1b should reverse Ca2+ -mediated manifestations of brain aging. Immunohistochemistry and qRT-PCR confirmed hippocampal FKBP1b overexpression 4-6 weeks after injection. Compared to aged vector controls, aged rats overexpressing FKBP1b showed dramatic enhancement of spatial memory, which correlated with marked reduction of sAHP magnitude. Furthermore, simultaneous electrophysiological recording and Ca2+ imaging in hippocampal neurons revealed that the sAHP reduction was associated with a decrease in parallel RyR-mediated Ca2+ transients. Thus, hippocampal FKBP1b overexpression reversed key aspects of Ca2+ dysregulation and cognitive impairment in aging rats, supporting the novel hypothesis that declining FKBP1b is a molecular mechanism underlying aging-related Ca2+ dysregulation and unhealthy brain aging and pointing to FKBP1b as a potential therapeutic target. SIGNIFICANCE STATEMENT This paper reports critical tests of a novel hypothesis that proposes a molecular mechanism of unhealthy brain aging and possibly, Alzheimer's disease. For more than 30 years, evidence has been accumulating that brain aging is associated with dysregulation of calcium in neurons. Recently, we found that FK506-binding protein 12.6/1b (FKBP1b), a small protein that regulates calcium, declines with aging in the hippocampus, a brain region important for memory. Here we used gene therapy approaches and found that raising FKBP1b reversed calcium dysregulation and memory impairment in aging rats, allowing them to perform a memory task as well as young rats. These studies identify a potential molecular mechanism of brain aging and may also have implications for treatment of Alzheimer's disease.
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Oliveira-Pinto AV, Andrade-Moraes CH, Oliveira LM, Parente-Bruno DR, Santos RM, Coutinho RA, Alho ATL, Leite REP, Suemoto CK, Grinberg LT, Pasqualucci CA, Jacob-Filho W, Lent R. Do age and sex impact on the absolute cell numbers of human brain regions? Brain Struct Funct 2015; 221:3547-59. [PMID: 26416171 DOI: 10.1007/s00429-015-1118-4] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2015] [Accepted: 09/23/2015] [Indexed: 12/11/2022]
Abstract
What is the influence of sex and age on the quantitative cell composition of the human brain? By using the isotropic fractionator to estimate absolute cell numbers in selected brain regions, we looked for sex- and age-related differences in 32 medial temporal lobes (comprised basically by the hippocampal formation, amygdala and parahippocampal gyrus), sixteen male (29-92 years) and sixteen female (25-82); and 31 cerebella, seventeen male (29-92 years) and fourteen female (25-82). These regions were dissected from the brain, fixed and homogenized, and then labeled with a DNA-marker (to count all nuclei) and with a neuron-specific nuclear marker (to estimate neuron number). Total number of cells in the medial temporal lobe was found to be 1.91 billion in men, and 1.47 billion in women, a difference of 23 %. This region showed 34 % more neurons in men than in women: 525.1 million against 347.4 million. In contrast, no sex differences were found in the cerebellum. Regarding the influence of age, a quadratic correlation was found between neuronal numbers and age in the female medial temporal lobe, suggesting an early increase followed by slight decline after age 50. The cerebellum showed numerical stability along aging for both neurons and non-neuronal cells. In sum, results indicate a sex-related regional difference in total and neuronal cell numbers in the medial temporal lobe, but not in the cerebellum. On the other hand, aging was found to impact on cell numbers in the medial temporal lobe, while the cerebellum proved resilient to neuronal losses in the course of life.
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Affiliation(s)
- Ana V Oliveira-Pinto
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Carlos H Andrade-Moraes
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Lays M Oliveira
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | | | - Raquel M Santos
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Renan A Coutinho
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
| | - Ana T L Alho
- Brazilian Aging Brain Study Group, LIM 22, University of São Paulo Medical School, São Paulo, Brazil.,Hospital Israelita Albert Einstein, Brain Institute, São Paulo, SP, Brazil
| | - Renata E P Leite
- Brazilian Aging Brain Study Group, LIM 22, University of São Paulo Medical School, São Paulo, Brazil.,Discipline of Geriatrics, University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Claudia K Suemoto
- Brazilian Aging Brain Study Group, LIM 22, University of São Paulo Medical School, São Paulo, Brazil.,Discipline of Geriatrics, University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Lea T Grinberg
- Brazilian Aging Brain Study Group, LIM 22, University of São Paulo Medical School, São Paulo, Brazil.,Department of Neurology and Pathology, University of California, San Francisco, USA
| | - Carlos A Pasqualucci
- Brazilian Aging Brain Study Group, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
| | - Wilson Jacob-Filho
- Brazilian Aging Brain Study Group, LIM 22, University of São Paulo Medical School, São Paulo, Brazil.,Discipline of Geriatrics, University of São Paulo Medical School, São Paulo, SP, Brazil
| | - Roberto Lent
- Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil. .,National Institute of Translational Neuroscience, Ministry of Science and Technology, São Paulo, Brazil. .,Instituto de Ciências Biomédicas, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas 373, Sl. F1-31, Ilha do Fundão, Rio de Janeiro, CEP 21941-902, Brazil.
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Naudí A, Cabré R, Jové M, Ayala V, Gonzalo H, Portero-Otín M, Ferrer I, Pamplona R. Lipidomics of human brain aging and Alzheimer's disease pathology. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2015; 122:133-89. [PMID: 26358893 DOI: 10.1016/bs.irn.2015.05.008] [Citation(s) in RCA: 115] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Lipids stimulated and favored the evolution of the brain. Adult human brain contains a large amount of lipids, and the largest diversity of lipid classes and lipid molecular species. Lipidomics is defined as "the full characterization of lipid molecular species and of their biological roles with respect to expression of proteins involved in lipid metabolism and function, including gene regulation." Therefore, the study of brain lipidomics can help to unravel the diversity and to disclose the specificity of these lipid traits and its alterations in neural (neurons and glial) cells, groups of neural cells, brain, and fluids such as cerebrospinal fluid and plasma, thus helping to uncover potential biomarkers of human brain aging and Alzheimer disease. This review will discuss the lipid composition of the adult human brain. We first consider a brief approach to lipid definition, classification, and tools for analysis from the new point of view that has emerged with lipidomics, and then turn to the lipid profiles in human brain and how lipids affect brain function. Finally, we focus on the current status of lipidomics findings in human brain aging and Alzheimer's disease pathology. Neurolipidomics will increase knowledge about physiological and pathological functions of brain cells and will place the concept of selective neuronal vulnerability in a lipid context.
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Affiliation(s)
- Alba Naudí
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, Spain
| | - Rosanna Cabré
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, Spain
| | - Mariona Jové
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, Spain
| | - Victoria Ayala
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, Spain
| | - Hugo Gonzalo
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, Spain
| | - Manuel Portero-Otín
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, Spain
| | - Isidre Ferrer
- Institute of Neuropathology, Bellvitge University Hospital, University of Barcelona, Biomedical Research Institute of Bellvitge, L'Hospitalet de Llobregat, Barcelona, Spain; Center for Biomedical Research on Neurodegenerative Diseases (CIBERNED), ISCIII, Madrid, Spain
| | - Reinald Pamplona
- Department of Experimental Medicine, University of Lleida-Biomedical Research Institute of Lleida, Lleida, Spain.
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Jiang X, Chai GS, Wang ZH, Hu Y, Li XG, Ma ZW, Wang Q, Wang JZ, Liu GP. Spatial training preserves associative memory capacity with augmentation of dendrite ramification and spine generation in Tg2576 mice. Sci Rep 2015; 5:9488. [PMID: 25820815 PMCID: PMC4377552 DOI: 10.1038/srep09488] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2014] [Accepted: 03/09/2015] [Indexed: 01/12/2023] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and there is currently no efficient cure for this devastating disease. Cognitive stimulation can delay memory loss during aging and in patients with mild cognitive impairment. In 3 × Tg-AD mice, training decreased the neuropathologies with transient amelioration of memory decline. However, the neurobiological mechanisms underlying the learning-improved memory capacity are poorly understood. Here, we found in Tg2576 mice spatial training in Morris water maze (MWM) remarkably improved the subsequent associative memory acquisition detected by contextual fear conditioning. We also found that spatial training enhanced long term potentiation, dendrite ramification and spine generation in hippocampal dentate gyrus (DG) and CA1 neurons at 24 h after the training. In the molecular level, the MWM training remarkably activated calcium/calmodulin-dependent protein kinase II (CaMKII) with elevation of glutamate AMPA receptor GluA1 subunit (GluA1), postsynaptic density protein 93 (PSD93) and postsynaptic density protein 95 (PSD95) in the hippocampus. Finally, the training also significantly ameliorated AD-like tau and amyloid pathologies. We conclude that spatial training in MWM preserves associative memory capacity in Tg2576 mice, and the mechanisms involve augmentation of dendrite ramification and spine generation in hippocampus.
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Affiliation(s)
- Xia Jiang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
- Department of Pathology, Hubei University of Chinese Medicine, Wuhan, 430065. P. R. China
| | - Gao-Shang Chai
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
- Department of Basic Medicine, Wuxi Medical School, Jiangnan University, Wuxi, Jiangsu Province, 214122, P. R. China
| | - Zhi-Hao Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
| | - Yu Hu
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
| | - Xiao-Guang Li
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
| | - Zhi-Wei Ma
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
| | - Qun Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
| | - Jian-Zhi Wang
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
| | - Gong-Ping Liu
- Department of Pathophysiology, Key Laboratory of Ministry of Education for Neurological Disorders, the School of Basal Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030. P. R. China
- Co-innovation Center of Neuroregeneration, Nantong University, Nantong, JS 226001, China
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Resveratrol prevents age-related memory and mood dysfunction with increased hippocampal neurogenesis and microvasculature, and reduced glial activation. Sci Rep 2015; 5:8075. [PMID: 25627672 PMCID: PMC4894403 DOI: 10.1038/srep08075] [Citation(s) in RCA: 113] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Accepted: 01/05/2015] [Indexed: 12/18/2022] Open
Abstract
Greatly waned neurogenesis, diminished microvasculature, astrocyte hypertrophy and activated microglia are among the most conspicuous structural changes in the aged hippocampus. Because these alterations can contribute to age-related memory and mood impairments, strategies efficacious for mitigating these changes may preserve cognitive and mood function in old age. Resveratrol, a phytoalexin found in the skin of red grapes having angiogenic and antiinflammatory properties, appears ideal for easing these age-related changes. Hence, we examined the efficacy of resveratrol for counteracting age-related memory and mood impairments and the associated detrimental changes in the hippocampus. Two groups of male F344 rats in late middle-age having similar learning and memory abilities were chosen and treated with resveratrol or vehicle for four weeks. Analyses at ~25 months of age uncovered improved learning, memory and mood function in resveratrol-treated animals but impairments in vehicle-treated animals. Resveratrol-treated animals also displayed increased net neurogenesis and microvasculature, and diminished astrocyte hypertrophy and microglial activation in the hippocampus. These results provide novel evidence that resveratrol treatment in late middle age is efficacious for improving memory and mood function in old age. Modulation of the hippocampus plasticity and suppression of chronic low-level inflammation appear to underlie the functional benefits mediated by resveratrol.
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Brichta L, Greengard P. Molecular determinants of selective dopaminergic vulnerability in Parkinson's disease: an update. Front Neuroanat 2014; 8:152. [PMID: 25565977 PMCID: PMC4266033 DOI: 10.3389/fnana.2014.00152] [Citation(s) in RCA: 137] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Accepted: 11/24/2014] [Indexed: 11/25/2022] Open
Abstract
Numerous disorders of the central nervous system (CNS) are attributed to the selective death of distinct neuronal cell populations. Interestingly, in many of these conditions, a specific subset of neurons is extremely prone to degeneration while other, very similar neurons are less affected or even spared for many years. In Parkinson’s disease (PD), the motor manifestations are primarily linked to the selective, progressive loss of dopaminergic (DA) neurons in the substantia nigra pars compacta (SNpc). In contrast, the very similar DA neurons in the ventral tegmental area (VTA) demonstrate a much lower degree of degeneration. Elucidating the molecular mechanisms underlying the phenomenon of differential DA vulnerability in PD has proven extremely challenging. Moreover, an increasing number of studies demonstrate that considerable molecular and electrophysiologic heterogeneity exists among the DA neurons within the SNpc as well as those within the VTA, adding yet another layer of complexity to the selective DA vulnerability observed in PD. The discovery of key pathways that regulate this differential susceptibility of DA neurons to degeneration holds great potential for the discovery of novel drug targets and the development of promising neuroprotective treatment strategies. This review provides an update on the molecular basis of the differential vulnerability of midbrain DA neurons in PD and highlights the most recent developments in this field.
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Affiliation(s)
- Lars Brichta
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University New York, NY, USA
| | - Paul Greengard
- Laboratory of Molecular and Cellular Neuroscience, The Rockefeller University New York, NY, USA
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Yoon SY, Choi JU, Cho MH, Yang KM, Ha H, Chung IJ, Cho GS, Kim DH. α-secretase cleaved amyloid precursor protein (APP) accumulates in cholinergic dystrophic neurites in normal, aged hippocampus. Neuropathol Appl Neurobiol 2014; 39:800-16. [PMID: 23414335 DOI: 10.1111/nan.12032] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2012] [Accepted: 01/31/2013] [Indexed: 12/17/2022]
Abstract
AIMS Dystrophic neurites are associated with β-amyloid (Aβ) plaques in the brains of Alzheimer's disease (AD) patients and are also found in some specific areas of normal, aged brains. This study assessed the molecular characteristics of dystrophic neurites in normal ageing and its difference from AD. METHODS We compared the dystrophic neurites in normal aged human brains (age 20-70 years) and AD brains (Braak stage 4-6) by immunostaining against ChAT, synaptophysin, γ-tubulin, cathepsin-D, Aβ1-16, Aβ17-24, amyloid precursor protein (APP)-CT695 and APP-NT. We then tested the reproducibility in C57BL/6 mice neurone cultures. RESULTS In normal, aged mice and humans, we found an increase in clustered dystrophic neurites of cholinergic neurones in CA1 regions of the hippocampus and layer II and III regions of the entorhinal cortex, which are the major and earliest affected areas in AD. These dystrophic neurites showed accumulation of sAPPα peptides cleaved from the amyloid precursor protein by α-secretase rather than Aβ or C-terminal fragments. In contrast, Aβ and APP-CTFs accumulated in the dystrophic neurites in and around Aβ plaques of AD patients. Several experiments suggested that the accumulation of sAPPα resulted from ageing-related proteasomal dysfunction. CONCLUSIONS Ageing-associated impairment of the proteasomal system and accumulation of sAPPα at cholinergic neurites in specific areas of brain regions associated with memory could be associated with the normal decline of memory in aged individuals. In addition, these age-related changes might be the most vulnerable targets of pathological insults that result in pathological accumulation of Aβ and/or APP-CTFs and lead to neurodegenerative conditions such as AD.
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Affiliation(s)
- S-Y Yoon
- Department of Anatomy and Cell Biology, Cell Dysfunction Research Center (CDRC), Bio-Medical Institute of Technology (BMIT), University of Ulsan College of Medicine, Seoul, Korea
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Selective vulnerability related to aging in large-scale resting brain networks. PLoS One 2014; 9:e108807. [PMID: 25271846 PMCID: PMC4182761 DOI: 10.1371/journal.pone.0108807] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 09/04/2014] [Indexed: 01/20/2023] Open
Abstract
Normal aging is associated with cognitive decline. Evidence indicates that large-scale brain networks are affected by aging; however, it has not been established whether aging has equivalent effects on specific large-scale networks. In the present study, 40 healthy subjects including 22 older (aged 60–80 years) and 18 younger (aged 22–33 years) adults underwent resting-state functional MRI scanning. Four canonical resting-state networks, including the default mode network (DMN), executive control network (ECN), dorsal attention network (DAN) and salience network, were extracted, and the functional connectivities in these canonical networks were compared between the younger and older groups. We found distinct, disruptive alterations present in the large-scale aging-related resting brain networks: the ECN was affected the most, followed by the DAN. However, the DMN and salience networks showed limited functional connectivity disruption. The visual network served as a control and was similarly preserved in both groups. Our findings suggest that the aged brain is characterized by selective vulnerability in large-scale brain networks. These results could help improve our understanding of the mechanism of degeneration in the aging brain. Additional work is warranted to determine whether selective alterations in the intrinsic networks are related to impairments in behavioral performance.
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Jacob MS, Duffy CJ. Might cortical hyper-responsiveness in aging contribute to Alzheimer's disease? PLoS One 2014; 9:e105962. [PMID: 25208332 PMCID: PMC4160186 DOI: 10.1371/journal.pone.0105962] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2014] [Accepted: 07/25/2014] [Indexed: 01/23/2023] Open
Abstract
Our goal is to understand the neural basis of functional impairment in aging and Alzheimer's disease (AD) to be able to characterize clinically significant decline and assess therapeutic efficacy. We used frequency-tagged ERPs to word and motion stimuli to study the effects of stimulus conditions and selective attention. ERPs to word or motion increase when a task-irrelevant 2nd stimulus is added, but decrease when the task is moved to that 2nd stimulus. Spectral analyses show task effects on response power without 2nd stimulus effects. However, phase coherence shows both 2nd stimulus and task effects. Thus, power and coherence are dissociably modulated by stimulus and task effects. Task-dependent phase coherence successively declines in aging and AD. In contrast, task-dependent spectral power increases in aging, only to decrease in AD. We hypothesize that age-related declines in signal coherence, associated with increased power generation, stresses neurons and contributes to the loss of response power and the development of functional impairment in AD.
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Affiliation(s)
- Michael S. Jacob
- Department of Neurology and the Center for Visual Science, The University of Rochester Medical Center, Rochester, New York, United States of America
- Department of Psychiatry, The University of California San Francisco Medical Center, San Francisco, California, United States of America
| | - Charles J. Duffy
- Department of Neurology and the Center for Visual Science, The University of Rochester Medical Center, Rochester, New York, United States of America
- * E-mail:
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A Validation Study of Memory and Executive Functions Indexes in French-Speaking Healthy Young and Older Adults. Can J Aging 2014; 33:60-71. [DOI: 10.1017/s0714980813000445] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022] Open
Abstract
RÉSUMÉDes scores composites mesurant les fonctions temporales médianes (FTM)/la mémoire et les fonctions frontales (FF)/exécutives sont utilisés pour indexer les changements cognitifs reliés au vieillissement. L’utilisation de ces scores en recherche gagne en popularité, mais s’appuie essentiellement sur les résultats de tests neuropsychologiques auprès des populations anglophones. Cette étude visait à valider les scores composites des FTM/la mémoire et FF/exécutives auprès d’adultes francophones. Quatre-vingt-dix-huit participants sains (32 jeunes et 66 âgés) ont été évalués à l’aide de trois tests neuropsychologiques associés aux FTM et cinq tests associés aux FF. Une analyse factorielle effectuée sur les scores résiduels indépendants de l’âge indique que les tests associés aux FTM et ceux associés aux FF se regroupent en deux facteurs distincts. Une analyse de type « bootstrapping » impliquant 1 000 rééchantillons indique que sept tests sont stables. Cette étude valide pour la première fois en français, des scores composites mesurant les FTM et FF.
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Andrade-Moraes CH, Oliveira-Pinto AV, Castro-Fonseca E, da Silva CG, Guimarães DM, Szczupak D, Parente-Bruno DR, Carvalho LR, Polichiso L, Gomes BV, Oliveira LM, Rodriguez RD, Leite RE, Ferretti-Rebustini RE, Jacob-Filho W, Pasqualucci CA, Grinberg LT, Lent R. Cell number changes in Alzheimer's disease relate to dementia, not to plaques and tangles. Brain 2013; 136:3738-52. [PMID: 24136825 PMCID: PMC3859218 DOI: 10.1093/brain/awt273] [Citation(s) in RCA: 125] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2012] [Revised: 08/04/2013] [Accepted: 08/04/2013] [Indexed: 12/25/2022] Open
Abstract
Alzheimer's disease is the commonest cause of dementia in the elderly, but its pathological determinants are still debated. Amyloid-β plaques and neurofibrillary tangles have been implicated either directly as disruptors of neural function, or indirectly by precipitating neuronal death and thus causing a reduction in neuronal number. Alternatively, the initial cognitive decline has been attributed to subtle intracellular events caused by amyloid-β oligomers, resulting in dementia after massive synaptic dysfunction followed by neuronal degeneration and death. To investigate whether Alzheimer's disease is associated with changes in the absolute cell numbers of ageing brains, we used the isotropic fractionator, a novel technique designed to determine the absolute cellular composition of brain regions. We investigated whether plaques and tangles are associated with neuronal loss, or whether it is dementia that relates to changes of absolute cell composition, by comparing cell numbers in brains of patients severely demented with those of asymptomatic individuals-both groups histopathologically diagnosed as Alzheimer's-and normal subjects with no pathological signs of the disease. We found a great reduction of neuronal numbers in the hippocampus and cerebral cortex of demented patients with Alzheimer's disease, but not in asymptomatic subjects with Alzheimer's disease. We concluded that neuronal loss is associated with dementia and not the presence of plaques and tangles, which may explain why subjects with histopathological features of Alzheimer's disease can be asymptomatic; and exclude amyloid-β deposits as causes for the reduction of neuronal numbers in the brain. We found an increase of non-neuronal cell numbers in the cerebral cortex and subcortical white matter of demented patients with Alzheimer's disease when compared with asymptomatic subjects with Alzheimer's disease and control subjects, suggesting a reactive glial cell response in the former that may be related to the symptoms they present.
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Affiliation(s)
| | | | - Emily Castro-Fonseca
- 1 Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | - Camila G. da Silva
- 1 Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | - Daniel M. Guimarães
- 1 Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | - Diego Szczupak
- 1 Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | | | | | - Lívia Polichiso
- 2 Ageing Brain Study Group, Department of Pathology, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- 3 Department of Neurology, University of California, San Francisco, USA
| | - Bruna V. Gomes
- 1 Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | - Lays M. Oliveira
- 1 Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
| | - Roberta D. Rodriguez
- 2 Ageing Brain Study Group, Department of Pathology, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
| | - Renata E.P. Leite
- 2 Ageing Brain Study Group, Department of Pathology, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
| | - Renata E.L. Ferretti-Rebustini
- 2 Ageing Brain Study Group, Department of Pathology, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- 4 University of São Paulo Nursing School, São Paulo, Brazil
| | - Wilson Jacob-Filho
- 2 Ageing Brain Study Group, Department of Pathology, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- 5 Division of Geriatrics, University of São Paulo, Brazil
| | - Carlos A. Pasqualucci
- 2 Ageing Brain Study Group, Department of Pathology, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
| | - Lea T. Grinberg
- 2 Ageing Brain Study Group, Department of Pathology, LIM 22, University of São Paulo Medical School, São Paulo, Brazil
- 3 Department of Neurology, University of California, San Francisco, USA
| | - Roberto Lent
- 1 Institute of Biomedical Sciences, Federal University of Rio de Janeiro, Brazil
- 6 National Institute of Translational Neuroscience, Ministry of Science and Technology, Brazil
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Crowe SE, Ellis-Davies GCR. In vivo characterization of a bigenic fluorescent mouse model of Alzheimer's disease with neurodegeneration. J Comp Neurol 2013; 521:2181-94. [PMID: 23348594 DOI: 10.1002/cne.23306] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 12/14/2012] [Accepted: 01/17/2013] [Indexed: 11/11/2022]
Abstract
The loss of cognitive function in Alzheimer's disease (AD) patients is strongly correlated with the loss of neurons in various regions of the brain. We have created a new fluorescent bigenic mouse model of AD by crossing "H-line" yellow fluorescent protein (YFP) mice with the 5xFAD mouse model, which we call the 5XY mouse model. The 5xFAD mouse has been shown to have significant loss of L5 pyramidal neurons by 12 months of age. These neurons are transgenically labeled with YFP in the 5XY mouse, which enable longitudinal imaging of structural changes. In the 5XY mice, we observed an appearance of axonal dystrophies, with two distinct morphologies in the early stages of the disease progression. Simple swelling dystrophies are transient in nature and are not directly associated with amyloid plaques. Rosette dystrophies are more complex structures that remained stable throughout all imaging sessions, and always surrounded an amyloid plaque. Plaque growth was followed over 4 weeks, and significant growth was seen between weekly imaging sessions. In addition to axonal dystrophy appearance and plaque growth, we were able to follow spine stability in 4-month old 5XY mice, which revealed no significant loss of spines. 5XY mice also showed a striking shrinkage of the neocortex at older ages (12-14 months). The 5XY mouse model may be a valuable tool for studying specific events in the degeneration of the neocortex, and may suggest new avenues for therapeutic intervention.
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Affiliation(s)
- Sarah E Crowe
- Department of Neuroscience, Mount Sinai School of Medicine, New York, New York 10029, USA
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41
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Mitew S, Kirkcaldie MTK, Dickson TC, Vickers JC. Altered synapses and gliotransmission in Alzheimer's disease and AD model mice. Neurobiol Aging 2013; 34:2341-51. [PMID: 23643146 DOI: 10.1016/j.neurobiolaging.2013.04.010] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2012] [Accepted: 04/03/2013] [Indexed: 11/26/2022]
Abstract
Amyloid-β (Aβ) plaque accumulation in Alzheimer's disease (AD) is associated with glutamatergic synapse loss, but less is known about its effect on inhibitory synapses. Here, we demonstrate that vesicular γ-aminobutyric acid (GABA) transporter (VGAT) presynaptic bouton density is unaffected in human preclinical and end-stage AD and in APP/PS1 transgenic (TG) mice. Conversely, excitatory vesicular glutamate transporter 1 (VGlut1) boutons are significantly reduced in end-stage AD cases and less reduced in preclinical AD cases and TGs. Aged TGs also show reduced protein levels of VGlut1 and synaptophysin but not VGAT or glutamate decarboxylase (GAD). These findings indicate that GABAergic synapses are preserved in human AD and mouse TGs. Synaptosomes isolated from plaque-rich TG cortex had significantly higher GAD activity than those from plaque-free cerebellum or the cortex of wild-type littermates. Using tissue fractionation, this increased activity was localized to glial synaptosomes, suggesting that Aβ plaques stimulate increased astrocyte GABA synthesis.
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Affiliation(s)
- Stanislaw Mitew
- Wicking Dementia Research and Education Centre, University of Tasmania, Hobart, Tasmania, Australia
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42
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Tseng BY, Uh J, Rossetti HC, Cullum CM, Diaz-Arrastia RF, Levine BD, Lu H, Zhang R. Masters athletes exhibit larger regional brain volume and better cognitive performance than sedentary older adults. J Magn Reson Imaging 2013; 38:1169-76. [PMID: 23908143 DOI: 10.1002/jmri.24085] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2012] [Accepted: 01/25/2013] [Indexed: 11/09/2022] Open
Abstract
PURPOSE To investigate differences in the age-related decline in brain tissue concentration between Masters athletes and sedentary older adults. MATERIALS AND METHODS Twelve Masters athletes (MA) (three females, age = 72.4 ± 5.6 years, endurance training >15 years), 12 sedentary elderly (SE) similar in age and educational level (four females, age = 74.6 ± 4.3 years), and nine young controls (YC) (four females, age = 27.2 ± 3.6 years) participated. T1-weighted high-resolution (1 × 1 × 1mm(3) ) images were acquired. Voxel-based analysis was conducted to identify clusters showing tissue concentration differences with t-tests. Cognitive function was assessed using a standard clinical battery focused on executive function and memory. RESULTS Two MA and two SE were unable to complete the magnetic resonance imaging (MRI) study. Both SE and MA showed lower gray matter (GM) concentrations than YC in the superior, inferior and middle frontal gyrus, superior temporal gyrus, postcentral gyrus, and the cingulate gyrus (PFDR-corrected < 0.001) and lower white matter (WM) concentrations in the inferior frontal gyrus and precentral gyrus (PFDR-corrected < 0.005). Notably, MA showed higher GM and WM concentrations than SE in the subgyral, cuneus, and precuneus regions related to visuospatial function, motor control, and working memory (PFDR-corrected < 0.005). After controlling for estimated intelligence, MA outperformed SE on tasks of letter (P < 0.01) and category (P < 0.05) fluency. CONCLUSION Life-long exercise may confer benefits to some aspects of executive function and age-related brain tissue loss in the regions related to visuospatial function, motor control, and working memory in older adults.
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Affiliation(s)
- Benjamin Y Tseng
- Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital Dallas, Dallas, Texas, USA; Department of Internal Medicine-Cardiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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Habenschuss S, Puhr H, Maass W. Emergence of optimal decoding of population codes through STDP. Neural Comput 2013; 25:1371-407. [PMID: 23517096 DOI: 10.1162/neco_a_00446] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The brain faces the problem of inferring reliable hidden causes from large populations of noisy neurons, for example, the direction of a moving object from spikes in area MT. It is known that a theoretically optimal likelihood decoding could be carried out by simple linear readout neurons if weights of synaptic connections were set to certain values that depend on the tuning functions of sensory neurons. We show here that such theoretically optimal readout weights emerge autonomously through STDP in conjunction with lateral inhibition between readout neurons. In particular, we identify a class of optimal STDP learning rules with homeostatic plasticity, for which the autonomous emergence of optimal readouts can be explained on the basis of a rigorous learning theory. This theory shows that the network motif we consider approximates expectation-maximization for creating internal generative models for hidden causes of high-dimensional spike inputs. Notably, we find that this optimal functionality can be well approximated by a variety of STDP rules beyond those predicted by theory. Furthermore, we show that this learning process is very stable and automatically adjusts weights to changes in the number of readout neurons, the tuning functions of sensory neurons, and the statistics of external stimuli.
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Affiliation(s)
- Stefan Habenschuss
- Institute for Theoretical Computer Science, Graz University of Technology, A-8010 Graz, Austria.
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Spine pruning in 5xFAD mice starts on basal dendrites of layer 5 pyramidal neurons. Brain Struct Funct 2013; 219:571-80. [PMID: 23417057 DOI: 10.1007/s00429-013-0518-6] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2012] [Accepted: 02/01/2013] [Indexed: 12/19/2022]
Abstract
Transgenic mice with Alzheimer's disease (AD) mutations have been widely used to model changes in neuronal structure and function. While there are clear gross structural changes in post-mortem brains of AD patients, most mouse models of AD do not recapitulate the considerable loss of neurons. Furthermore, possible connections between early subtle structural changes and the loss of neurons are difficult to study. In an attempt to start unraveling how neurons are affected during the early stages of what becomes full neurodegeneration, we crossed a mouse model of familial AD, which displays massive neocortical neurodegeneration (the 5xFAD mouse), with the fluorescent H-line YFP mouse. This novel bigenic mouse model of AD, which we have named the 5XY mouse, expresses YFP in principal neurons in the cortex such that even fine details of cells are clearly visible. Such bright fluorescence allowed us to use high-resolution confocal microscopy to quantify changes in spine density in the somatosensory cortex, prefrontal cortex, and hippocampus at 2, 4, and 6 months of age. A significant loss of spines on basal dendrites in the somatosensory and prefrontal cortices of 6-month-old 5XY female mice was found. There was no observed spine loss at 6 months of age on the oblique dendrites of the hippocampus in the same mice. These data suggest that spine loss is an early event in the degeneration of the neocortical neurons in 5xFAD mice and a likely contributor to the cognitive impairments reported previously in this AD mouse model.
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Liang Z, Chen YM, Meng X, Wang Y, Zhou BZ, Xie YY, He WS. [Aging affects early stage direction selectivity of MT cells in rhesus monkeys]. DONG WU XUE YAN JIU = ZOOLOGICAL RESEARCH 2013; 33:498-502. [PMID: 23019032 DOI: 10.3724/sp.j.1141.2012.05498] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The middle temporal area (MT/V5) plays an important role in motion processing. Neurons in this area have a strongly selective response to the moving direction of objects and as such, the selectivity of MT neurons was proposed to be a neural mechanism for the perception of motion. Our previous studies have found degradation in direction selectivity of MT neurons in old monkeys, but this direction selectivity was calculated during the whole response time and the results were not able to uncover the mechanism of motion perception over a time course. Furthermore, experiments have found that direction selectivity was enhanced by attention at a later stage. Therefore, the response should be excluded in experiments with anesthesia. To further characterize the neural mechanism over a time course, we investigated the age-related changes of direction selectivity in the early stage by comparing the proportions of direction selective MT cells in old and young macaque monkeys using in vivo single-cell recording techniques. Our results show that the proportion of early-stage-direction-selective cells is lower in old monkeys than in young monkeys, and that the early stage direction bias (esDB) of old MT cells decreased relative to young MT cells. Furthermore, the proportion of MT cells having strong early stage direction selectivity in old monkeys was decreased. Accordingly, the functional degradation in the early stage of MT cells may mediate perceptual declines of old primates in visual motion tasks.
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Affiliation(s)
- Zhen Liang
- Department of Bio-Medical Engineering, Anhui Medical University, Hefei Anhui 230032, China
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46
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Harb R, Whiteus C, Freitas C, Grutzendler J. In vivo imaging of cerebral microvascular plasticity from birth to death. J Cereb Blood Flow Metab 2013; 33:146-56. [PMID: 23093067 PMCID: PMC3597363 DOI: 10.1038/jcbfm.2012.152] [Citation(s) in RCA: 140] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Cerebral function and viability are critically dependent on efficient delivery of oxygen and glucose through the microvasculature. Here, we studied individual microvessels in the intact brain using high-resolution confocal imaging and long-term time-lapse two-photon microscopy across the lifetime of a mouse. In the first postnatal month, we found large-scale sprouting but to our surprise the majority of sprouts underwent pruning and only a small fraction became perfused capillaries. After the first month, microvessel formation and elimination decreased and the net number of vessels stabilized. Although vascular stability was the hallmark of the adult brain, some vessel formation and elimination continued throughout life. In young adult mice, vessel formation was markedly increased after exposure to hypoxia; however, upon return to normoxia, no vessel elimination was observed, suggesting that new vessels constitute a long-term adaptive response to metabolic challenges. This plasticity was markedly reduced in older adults and aging where hypoxia-induced angiogenesis was absent. Our study describes, for the first time in vivo patterns of cerebral microvascular remodeling throughout life. Disruption of the observed balance between baseline turnover and vascular stability may underlie a variety of developmental and age-related degenerative neurological disorders.
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Affiliation(s)
- Roa Harb
- Department of Laboratory Medicine, Yale University School of Medicine, New Haven, CT, USA
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Prestia A, Baglieri A, Pievani M, Bonetti M, Rasser PE, Thompson PM, Marino S, Bramanti P, Frisoni GB. The in vivo topography of cortical changes in healthy aging and prodromal Alzheimer's disease. APPLICATION OF BRAIN OSCILLATIONS IN NEUROPSYCHIATRIC DISEASES - SELECTED PAPERS FROM “BRAIN OSCILLATIONS IN COGNITIVE IMPAIRMENT AND NEUROTRANSMITTERS” CONFERENCE, ISTANBUL, TURKEY, 29 APRIL–1 MAY 2011 2013; 62:67-80. [DOI: 10.1016/b978-0-7020-5307-8.00004-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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48
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PET imaging in the differential diagnosis of vascular dementia. J Neurol Sci 2012; 322:268-73. [DOI: 10.1016/j.jns.2012.09.023] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Revised: 08/20/2012] [Accepted: 09/18/2012] [Indexed: 01/21/2023]
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Huffman K. The developing, aging neocortex: how genetics and epigenetics influence early developmental patterning and age-related change. Front Genet 2012; 3:212. [PMID: 23087707 PMCID: PMC3473232 DOI: 10.3389/fgene.2012.00212] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2012] [Accepted: 09/26/2012] [Indexed: 11/13/2022] Open
Abstract
A hallmark of mammalian development is the generation of functional subdivisions within the nervous system. In humans, this regionalization creates a complex system that regulates behavior, cognition, memory, and emotion. During development, specification of neocortical tissue that leads to functional sensory and motor regions results from an interplay between cortically intrinsic, molecular processes, such as gene expression, and extrinsic processes regulated by sensory input. Cortical specification in mice occurs pre- and perinatally, when gene expression is robust and various anatomical distinctions are observed alongside an emergence of physiological function. After patterning, gene expression continues to shift and axonal connections mature into an adult form. The function of adult cortical gene expression may be to maintain neocortical subdivisions that were established during early patterning. As some changes in neocortical gene expression have been observed past early development into late adulthood, gene expression may also play a role in the altered neocortical function observed in age-related cognitive decline and brain dysfunction. This review provides a discussion of how neocortical gene expression and specific patterns of neocortical sensori-motor axonal connections develop and change throughout the lifespan of the animal. We posit that a role of neocortical gene expression in neocortex is to regulate plasticity mechanisms that impact critical periods for sensory and motor plasticity in aging. We describe results from several studies in aging brain that detail changes in gene expression that may relate to microstructural changes observed in brain anatomy. We discuss the role of altered glucocorticoid signaling in age-related cognitive and functional decline, as well as how aging in the brain may result from immune system activation. We describe how caloric restriction or reduction of oxidative stress may ameliorate effects of aging on the brain.
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Affiliation(s)
- Kelly Huffman
- Department of Psychology, University of California Riverside, CA, USA
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He J, Wong VSS, Fletcher E, Maillard P, Lee DY, Iosif AM, Singh B, Martinez O, Roach AE, Lockhart SN, Beckett L, Mungas D, Farias ST, Carmichael O, DeCarli C. The contributions of MRI-based measures of gray matter, white matter hyperintensity, and white matter integrity to late-life cognition. AJNR Am J Neuroradiol 2012; 33:1797-803. [PMID: 22538073 DOI: 10.3174/ajnr.a3048] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
BACKGROUND AND PURPOSE GM volume, WMH volume, and FA are each associated with cognition; however, few studies have detected whether these 3 different types of MR imaging measurements exert independent or additive effects on cognitive performance. To detect their extent of contribution to cognitive performance, we explored the independent and additive contributions of GM atrophy, white matter injury, and white matter integrity to cognition in elderly patients. MATERIALS AND METHODS Two hundred and 9 elderly patients participated in the study: 97 were CN adults, 65 had MCI, and 47 had dementia. We measured GM on T1-weighted MR imaging, WMH on FLAIR, and FA on DTI, along with psychometrically matched measures of 4 domains of cognitive performance, including semantic memory, episodic memory, executive function, and spatial abilities. RESULTS As expected, patients with dementia performed significantly more poorly in all 4 cognitive domains, whereas patients with MCI performed generally less poorly than dementia patients, though considerable overlap in performance was present across groups. GM, FA, and WMH each differed significantly between diagnostic groups and were associated with cognitive measures. In multivariate models that included all 3 MR imaging measures (GM, WMH, and FA), GM volume was the strongest determinant of cognitive performance. CONCLUSIONS These results strongly suggest that MR imaging measures of GM are more closely associated with cognitive function than WM measures across a broad range of cognitive and functional impairment.
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Affiliation(s)
- J He
- Imaging of Dementia & Aging (IDeA) Laboratory, Department of Neurology, University of California, Davis, 1544 Newton Ct, Davis, CA 95618, USA.
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