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Ozgen MN, Sahin NE, Ertan N, Sahin B. Investigation of total cerebellar and flocculonodular lobe volume in Parkinson's disease and healthy individuals: a brain segmentation study. Neurol Sci 2024; 45:4291-4298. [PMID: 38622454 PMCID: PMC11306710 DOI: 10.1007/s10072-024-07509-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2024] [Accepted: 03/30/2024] [Indexed: 04/17/2024]
Abstract
BACKGROUND Parkinson's disease (PD) is a neurodegenerative disorder with an unexplored link to the cerebellum. In the pathophysiology of balance disorders in PD, the role of the flocculonodular lobe (FL) is linked to the impairment of the dopaminergic system. Dopamine deficiency can also lead to changes in cerebellum functions, disrupting balance control. This study compares cerebellar and FL volumes between healthy controls (HC) and PD patients, analyzing their correlation with clinical outcomes. METHODS We used magnetic resonance images of 23 PD patients (14 male, 9 female) and 24 HC (9 male, 15 female). Intracranial (ICV), total cerebellar, FL, and cerebellar gray matter volumes were measured using VolBrain. Clinical outcomes in PD patients were assessed using the Unified Parkinson's Disease Rating Scale (UPDRS-III) to evaluate motor function, with scores correlated to volumetric data. RESULTS The cerebellar and gray matter volumes in HC were 115.53 ± 10.44 cm3 and 84.83 ± 7.76 cm3, respectively, compared to 126.83 ± 13.47 cm3 and 92.37 ± 9.45 cm3 in PD patients, indicating significantly larger volumes in PD patients (p < 0.05). The flocculonodular lobe gray matter volume was 1.14 ± 0.19 cm3 in PD patients and 1.02 ± 0.13 cm3 in HC, but there was a significant increase in gray matter volume in PD patients between the groups (p < 0.05). In PD patients, significant negative correlations were observed between FL volume and the UPDRS-III scores (r = - 0.467, p = 0.033) and between UPDRS-III scores and both total (r = - 0.453, p = 0.039) and normalized (r = - 0.468, p = 0.032) gray matter volumes of the FL. CONCLUSION Although total gray matter volumes were larger in PD patients, the volumes of FL did not differ between groups. In Parkinson's disease, increased cerebellar volume may regulate fine motor movements rather than balance.
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Affiliation(s)
- Merve Nur Ozgen
- Department of Anatomy, Faculty of Medicine, Tokat Gaziosmanpaşa University, Tokat, Türkiye
| | - Necati Emre Sahin
- Department of Anatomy, Faculty of Medicine, Karabük University, Karabük, Türkiye
| | - Nurcan Ertan
- Radiology Clinic, Ankara Etlik City Hospital, Ankara, Türkiye
| | - Bunyamin Sahin
- Department of Anatomy, Faculty of Medicine, Ondokuz Mayıs University, Samsun, Türkiye.
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Fan Y, Wang A, Liu Z, Xing J, Zheng Z, Song F, Hou Z, Liu S. Integrated spatial metabolomics and network pharmacology to explore the pharmacodynamic substances and mechanism of Radix ginseng-Schisandra chinensis Herb Couple on Alzheimer's disease. Anal Bioanal Chem 2024; 416:4275-4288. [PMID: 38853180 DOI: 10.1007/s00216-024-05364-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2023] [Revised: 04/22/2024] [Accepted: 05/24/2024] [Indexed: 06/11/2024]
Abstract
Radix ginseng and Schisandra chinensis have been extensively documented in traditional Chinese medicine (TCM) for their potential efficacy in treating dementia. However, the precise mechanism of their therapeutic effects remains to be fully elucidated. In this study, air flow-assisted desorption electrospray ionization mass spectrometry imaging (AFADESI-MSI) and network pharmacology are used to investigate the pharmacodynamics and mechanism underlying the herbal combination consisting of Radix ginseng-Schisandra chinensis (RS) in a rodent model for Alzheimer's disease (AD). Brain histopathological findings suggested that RS attenuates hippocampal damage in AD mice, making this combination a potential AD treatment. Twenty-eight biomarkers were identified by spatial metabolomics analysis, which are intricately linked to neuroinflammation, neurotransmitter imbalance, energy deficiency, oxidative stress, and aberrant fatty acid metabolism in AD. The total extract of RS (TE) affected 22 of these biomarkers, with the small molecule components of RS (SN) significantly influencing 19 and the large molecule components of RS (PR) impacting 14. Nine small molecule components are likely to dominate the pharmacodynamics of RS. We constructed a target interaction network based on the corresponding bioactivities that revealed relationships amongst 11 key biomarkers, 8 active ingredients and 12 critical targets. This research illustrates the immense potential of spatial metabolomics and network pharmacology in the study of TCM, revealing the targets and mechanisms underlying herbal formulas.
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Affiliation(s)
- Yuting Fan
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China
| | - Aimin Wang
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China
| | - Zhiqiang Liu
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China
| | - Junpeng Xing
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
| | - Zhong Zheng
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
| | - Fengrui Song
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China
| | - Zong Hou
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
| | - Shu Liu
- State Key Laboratory of Electroanalytical Chemistry, National Center of Mass Spectrometry in Changchun and Jilin Province Key Laboratory of Chinese Medicine Chemistry and Mass Spectrometry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun, 130022, China.
- School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, 230026, China.
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3
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Ferrer I. Historical review: The golden age of the Golgi method in human neuropathology. J Neuropathol Exp Neurol 2024; 83:375-395. [PMID: 38622902 DOI: 10.1093/jnen/nlae031] [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] [Indexed: 04/17/2024] Open
Abstract
Golgi methods were used to study human neuropathology in the 1970s, 1980s, and 1990s of the last century. Although a relatively small number of laboratories applied these methods, their impact was crucial by increasing knowledge about: (1) the morphology, orientation, and localization of neurons in human cerebral and cerebellar malformations and ganglionic tumors, and (2) the presence of abnormal structures including large and thin spines (spine dysgenesis) in several disorders linked to mental retardation, focal enlargements of the axon hillock and dendrites (meganeurites) in neuronal storage diseases, growth cone-like appendages in Alzheimer disease, as well as abnormal structures in other dementias. Although there were initial concerns about their reliability, reduced dendritic branches and dendritic spines were identified as common alterations in mental retardation, dementia, and other pathological conditions. Similar observations in appropriate experimental models have supported many abnormalities that were first identified using Golgi methods in human material. Moreover, electron microscopy, immunohistochemistry, fluorescent tracers, and combined methods have proven the accuracy of pioneering observations uniquely visualized as 3D images of fully stained individual neurons. Although Golgi methods had their golden age many years ago, these methods may still be useful complementary tools in human neuropathology.
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Affiliation(s)
- Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona, Hospitalet de LLobregat, Spain
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4
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Arleo A, Bareš M, Bernard JA, Bogoian HR, Bruchhage MMK, Bryant P, Carlson ES, Chan CCH, Chen LK, Chung CP, Dotson VM, Filip P, Guell X, Habas C, Jacobs HIL, Kakei S, Lee TMC, Leggio M, Misiura M, Mitoma H, Olivito G, Ramanoël S, Rezaee Z, Samstag CL, Schmahmann JD, Sekiyama K, Wong CHY, Yamashita M, Manto M. Consensus Paper: Cerebellum and Ageing. CEREBELLUM (LONDON, ENGLAND) 2024; 23:802-832. [PMID: 37428408 PMCID: PMC10776824 DOI: 10.1007/s12311-023-01577-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 06/08/2023] [Indexed: 07/11/2023]
Abstract
Given the key roles of the cerebellum in motor, cognitive, and affective operations and given the decline of brain functions with aging, cerebellar circuitry is attracting the attention of the scientific community. The cerebellum plays a key role in timing aspects of both motor and cognitive operations, including for complex tasks such as spatial navigation. Anatomically, the cerebellum is connected with the basal ganglia via disynaptic loops, and it receives inputs from nearly every region in the cerebral cortex. The current leading hypothesis is that the cerebellum builds internal models and facilitates automatic behaviors through multiple interactions with the cerebral cortex, basal ganglia and spinal cord. The cerebellum undergoes structural and functional changes with aging, being involved in mobility frailty and related cognitive impairment as observed in the physio-cognitive decline syndrome (PCDS) affecting older, functionally-preserved adults who show slowness and/or weakness. Reductions in cerebellar volume accompany aging and are at least correlated with cognitive decline. There is a strongly negative correlation between cerebellar volume and age in cross-sectional studies, often mirrored by a reduced performance in motor tasks. Still, predictive motor timing scores remain stable over various age groups despite marked cerebellar atrophy. The cerebello-frontal network could play a significant role in processing speed and impaired cerebellar function due to aging might be compensated by increasing frontal activity to optimize processing speed in the elderly. For cognitive operations, decreased functional connectivity of the default mode network (DMN) is correlated with lower performances. Neuroimaging studies highlight that the cerebellum might be involved in the cognitive decline occurring in Alzheimer's disease (AD), independently of contributions of the cerebral cortex. Grey matter volume loss in AD is distinct from that seen in normal aging, occurring initially in cerebellar posterior lobe regions, and is associated with neuronal, synaptic and beta-amyloid neuropathology. Regarding depression, structural imaging studies have identified a relationship between depressive symptoms and cerebellar gray matter volume. In particular, major depressive disorder (MDD) and higher depressive symptom burden are associated with smaller gray matter volumes in the total cerebellum as well as the posterior cerebellum, vermis, and posterior Crus I. From the genetic/epigenetic standpoint, prominent DNA methylation changes in the cerebellum with aging are both in the form of hypo- and hyper-methylation, and the presumably increased/decreased expression of certain genes might impact on motor coordination. Training influences motor skills and lifelong practice might contribute to structural maintenance of the cerebellum in old age, reducing loss of grey matter volume and therefore contributing to the maintenance of cerebellar reserve. Non-invasive cerebellar stimulation techniques are increasingly being applied to enhance cerebellar functions related to motor, cognitive, and affective operations. They might enhance cerebellar reserve in the elderly. In conclusion, macroscopic and microscopic changes occur in the cerebellum during the lifespan, with changes in structural and functional connectivity with both the cerebral cortex and basal ganglia. With the aging of the population and the impact of aging on quality of life, the panel of experts considers that there is a huge need to clarify how the effects of aging on the cerebellar circuitry modify specific motor, cognitive, and affective operations both in normal subjects and in brain disorders such as AD or MDD, with the goal of preventing symptoms or improving the motor, cognitive, and affective symptoms.
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Affiliation(s)
- Angelo Arleo
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
| | - Martin Bareš
- First Department of Neurology, Faculty of Medicine, Masaryk University and St. Anne's Teaching Hospital, Brno, Czech Republic
- Department of Neurology, School of Medicine, University of Minnesota, Minneapolis, USA
| | - Jessica A Bernard
- Department of Psychological and Brain Sciences, Texas A&M University, 4235 TAMU, College Station, TX, 77843, USA
- Texas A&M Institute for Neuroscience, Texas A&M University, College Station, TX, USA
| | - Hannah R Bogoian
- Department of Psychology, Georgia State University, Atlanta, GA, USA
| | - Muriel M K Bruchhage
- Department of Psychology, Stavanger University, Institute of Social Sciences, Kjell Arholms Gate 41, 4021, Stavanger, Norway
- King's College London, Institute of Psychiatry, Psychology and Neuroscience, Centre for Neuroimaging Sciences, Box 89, De Crespigny Park, London, PO, SE5 8AF, UK
- Rhode Island Hospital, Department for Diagnostic Imaging, 1 Hoppin St, Providence, RI, 02903, USA
- Department of Paediatrics, Warren Alpert Medical School of Brown University, 222 Richmond St, Providence, RI, 02903, USA
| | - Patrick Bryant
- Freie Universität Berlin, Fachbereich Mathematik und Informatik, Arnimallee 12, 14195, Berlin, Germany
| | - Erik S Carlson
- Department of Psychiatry and Behavioural Sciences, University of Washington, Seattle, WA, USA
- Geriatric Research, Education and Clinical Center, Veteran's Affairs Medical Center, Puget Sound, Seattle, WA, USA
| | - Chetwyn C H Chan
- Department of Psychology, The Education University of Hong Kong, New Territories, Tai Po, Hong Kong, China
| | - Liang-Kung Chen
- Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University College of Medicine, Taipei, Taiwan
- Center for Geriatric and Gerontology, Taipei Veterans General Hospital, Taipei, Taiwan
- Taipei Municipal Gan-Dau Hospital (managed by Taipei Veterans General Hospital), Taipei, Taiwan
| | - Chih-Ping Chung
- Center for Healthy Longevity and Aging Sciences, National Yang Ming Chiao Tung University College of Medicine, Taipei, Taiwan
- Department of Neurology, Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Vonetta M Dotson
- Department of Psychology, Georgia State University, Atlanta, GA, USA
- Gerontology Institute, Georgia State University, Atlanta, GA, USA
| | - Pavel Filip
- Department of Neurology, Charles University, First Faculty of Medicine and General University Hospital, Prague, Czech Republic
- Center for Magnetic Resonance Research (CMRR), University of Minnesota, Minneapolis, MN, USA
| | - Xavier Guell
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Laboratory for Neuroanatomy and Cerebellar Neurobiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Christophe Habas
- CHNO Des Quinze-Vingts, INSERM-DGOS CIC 1423, 28 rue de Charenton, 75012, Paris, France
- Université Versailles St Quentin en Yvelines, Paris, France
| | - Heidi I L Jacobs
- School for Mental Health and Neuroscience, Alzheimer Centre Limburg, Maastricht University, PO BOX 616, 6200, MD, Maastricht, The Netherlands
- Faculty of Psychology and Neuroscience, Department of Cognitive Neuroscience, Maastricht University, PO BOX 616, 6200, MD, Maastricht, The Netherlands
- Gordon Center for Medical Imaging, Department of Radiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | | | - Tatia M C Lee
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Hong Kong, China
- Laboratory of Neuropsychology and Human Neuroscience, Department of Psychology, The University of Hong Kong, Hong Kong, China
| | - Maria Leggio
- Department of Psychology, Sapienza University of Rome, Rome, Italy
- Ataxia Laboratory, I.R.C.C.S. Santa Lucia Foundation, Rome, Italy
| | - Maria Misiura
- Department of Psychology, Georgia State University, Atlanta, GA, USA
| | - Hiroshi Mitoma
- Department of Medical Education, Tokyo Medical University, Tokyo, Japan
| | - Giusy Olivito
- Department of Psychology, Sapienza University of Rome, Rome, Italy
- Ataxia Laboratory, I.R.C.C.S. Santa Lucia Foundation, Rome, Italy
| | - Stephen Ramanoël
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, 17 rue Moreau, F-75012, Paris, France
- Université Côte d'Azur, LAMHESS, Nice, France
| | - Zeynab Rezaee
- Noninvasive Neuromodulation Unit, Experimental Therapeutics & Pathophysiology Branch, National Institute of Mental Health, NIH, Bethesda, USA
| | - Colby L Samstag
- Department of Psychiatry and Behavioural Sciences, University of Washington, Seattle, WA, USA
- Geriatric Research, Education and Clinical Center, Veteran's Affairs Medical Center, Puget Sound, Seattle, WA, USA
| | - Jeremy D Schmahmann
- Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Laboratory for Neuroanatomy and Cerebellar Neurobiology, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
- Ataxia Center, Cognitive Behavioural neurology Unit, Massachusetts General Hospital and Harvard Medical School, Boston, MA, USA
| | - Kaoru Sekiyama
- Graduate School of Advanced Integrated Studies in Human Survivability, Kyoto University, Kyoto, Japan
| | - Clive H Y Wong
- Department of Psychology, The Education University of Hong Kong, New Territories, Tai Po, Hong Kong, China
| | - Masatoshi Yamashita
- Research Center for Child Mental Development, University of Fukui, Fukui, Japan
- United Graduate School of Child Development, Osaka University, Kanazawa University, Hamamatsu University School of Medicine, Chiba University and University of Fukui, Osaka, Japan
| | - Mario Manto
- Service de Neurologie, Médiathèque Jean Jacquy, CHU-Charleroi, Charleroi, Belgium.
- Service des Neurosciences, University of Mons, Mons, Belgium.
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5
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Lopez G, Magaki SD, Williams CK, Paganini-Hill A, Vinters HV. Characterization of cerebellar amyloid-β deposits in Alzheimer disease. J Neuropathol Exp Neurol 2024; 83:72-78. [PMID: 38114098 PMCID: PMC10799296 DOI: 10.1093/jnen/nlad107] [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] [Indexed: 12/21/2023] Open
Abstract
Cerebellar amyloid-β (Aβ) plaques are a component of the diagnostic criteria used in Thal staging and ABC scoring for Alzheimer disease (AD) neuropathologic change. However, Aβ deposits in this anatomic compartment are unique and under-characterized; and their relationship with other pathological findings are largely undefined. In 73 cases of pure or mixed AD with an A3 score in the ABC criteria, parenchymal (plaques) and vascular (cerebral amyloid angiopathy [CAA]) cerebellar Aβ-42 deposits were characterized with respect to localization, morphology, density, and intensity. Over 85% of cases demonstrated cerebellar Aβ-42 parenchymal staining that correlated with a Braak stage V-VI/B3 score (p < 0.01). Among the 63 with cerebellar Aβ-42 deposits, a diffuse morphology was observed in 75% of cases, compact without a central dense core in 32%, and compact with a central dense core in 16% (all corresponding to plaques evident on hematoxylin and eosin staining). Cases with Purkinje cell (PC) loss showed higher proportions of PC layer Aβ-42 staining than cases without PC loss (88% vs 44%, p = 0.02), suggesting a link between Aβ-42 deposition and PC damage. Among all 73 cases, CAA was observed in the parenchymal vessels of 19% of cases and in leptomeningeal vessels in 44% of cases.
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Affiliation(s)
- Gianluca Lopez
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Department of Biomedical, Surgical and Dental Sciences, University of Milan, Milan, Italy
- Division of Pathology, Fondazione IRCCS Ca’ Granda—Ospedale Maggiore Policlinico, Milan, Italy
| | - Shino D Magaki
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Christopher Kazu Williams
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
| | - Annlia Paganini-Hill
- Department of Neurology, University of California, Irvine, Irvine, California, USA
| | - Harry V Vinters
- Section of Neuropathology, Department of Pathology and Laboratory Medicine, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, California, USA
- Department of Neurology, Ronald Reagan UCLA Medical Center and David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
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Bou Ghanem A, Hussayni Y, Kadbey R, Ratel Y, Yehya S, Khouzami L, Ghadieh HE, Kanaan A, Azar S, Harb F. Exploring the complexities of 1C metabolism: implications in aging and neurodegenerative diseases. Front Aging Neurosci 2024; 15:1322419. [PMID: 38239489 PMCID: PMC10794399 DOI: 10.3389/fnagi.2023.1322419] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2023] [Accepted: 12/11/2023] [Indexed: 01/22/2024] Open
Abstract
The intricate interplay of one-carbon metabolism (OCM) with various cellular processes has garnered substantial attention due to its fundamental implications in several biological processes. OCM serves as a pivotal hub for methyl group donation in vital biochemical reactions, influencing DNA methylation, protein synthesis, and redox balance. In the context of aging, OCM dysregulation can contribute to epigenetic modifications and aberrant redox states, accentuating cellular senescence and age-associated pathologies. Furthermore, OCM's intricate involvement in cancer progression is evident through its capacity to provide essential one-carbon units crucial for nucleotide synthesis and DNA methylation, thereby fueling uncontrolled cell proliferation and tumor development. In neurodegenerative disorders like Alzheimer's and Parkinson's, perturbations in OCM pathways are implicated in the dysregulation of neurotransmitter synthesis and mitochondrial dysfunction, contributing to disease pathophysiology. This review underscores the profound impact of OCM in diverse disease contexts, reinforcing the need for a comprehensive understanding of its molecular complexities to pave the way for targeted therapeutic interventions across inflammation, aging and neurodegenerative disorders.
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Affiliation(s)
- Ayman Bou Ghanem
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
| | - Yaman Hussayni
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
| | - Raghid Kadbey
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
| | - Yara Ratel
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
| | - Shereen Yehya
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
| | - Lara Khouzami
- College of Natural and Health Sciences, Zayed University, Dubai, United Arab Emirates
| | - Hilda E. Ghadieh
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
- AUB Diabetes, American University of Beirut Medical Center, Beirut, Lebanon
| | - Amjad Kanaan
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
| | - Sami Azar
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
| | - Frederic Harb
- Faculty of Medicine and Medical Sciences, University of Balamand, Tripoli, Lebanon
- AUB Diabetes, American University of Beirut Medical Center, Beirut, Lebanon
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7
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Bernard JA, McOwen KM, Huynh AT. New Frontiers for the Understanding of Aging: The Power and Possibilities of Studying the Cerebellum. Curr Opin Behav Sci 2023; 54:101311. [PMID: 38496767 PMCID: PMC10939048 DOI: 10.1016/j.cobeha.2023.101311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024]
Abstract
Understanding behavior in aging has benefited greatly from cognitive neuroscience. Our foundational understanding of the brain in advanced age is based on what now amounts to several decades of work demonstrating differences in brain structure, network organization, and function. Earlier work in this field was focused primarily on the prefrontal cortex and hippocampus. More recent evidence has expanded our understanding of the aging brain to also implicate the cerebellum. Recent frameworks have suggested that the cerebellum may act as scaffolding for cortical function, and there is an emerging literature implicating the structure in Alzheimer's disease. At this juncture, there is evidence highlighting the potential importance of the cerebellum in advanced age, though the field of study is relatively nascent. Here, we provide an overview of key findings in the literature as it stands now and highlight several key future directions for study with respect to the cerebellum in aging.
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Affiliation(s)
- Jessica A. Bernard
- Department of Psychological and Brain Sciences
- Texas A&M Institute for Neuroscience
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8
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Carello-Collar G, Bellaver B, Ferreira PCL, Ferrari-Souza JP, Ramos VG, Therriault J, Tissot C, De Bastiani MA, Soares C, Pascoal TA, Rosa-Neto P, Souza DO, Zimmer ER. The GABAergic system in Alzheimer's disease: a systematic review with meta-analysis. Mol Psychiatry 2023; 28:5025-5036. [PMID: 37419974 DOI: 10.1038/s41380-023-02140-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 05/17/2023] [Accepted: 06/16/2023] [Indexed: 07/09/2023]
Abstract
The γ-aminobutyric acid (GABA)ergic system is the primary inhibitory neurotransmission system in the mammalian brain. Its dysregulation has been shown in multiple brain conditions, but in Alzheimer's disease (AD) studies have provided contradictory results. Here, we conducted a systematic review with meta-analysis to investigate whether the GABAergic system is altered in AD patients compared to healthy controls (HC), following the PRISMA 2020 Statement. We searched PubMed and Web of Science from database inception to March 18th, 2023 for studies reporting GABA, glutamate decarboxylase (GAD) 65/67, GABAA, GABAB, and GABAC receptors, GABA transporters (GAT) 1-3 and vesicular GAT in the brain, and GABA levels in the cerebrospinal fluid (CSF) and blood. Heterogeneity was estimated using the I2 index, and the risk of bias was assessed with an adapted questionnaire from the Joanna Briggs Institute Critical Appraisal Tools. The search identified 3631 articles, and 48 met the final inclusion criteria (518 HC, mean age 72.2, and 603 AD patients, mean age 75.6). Random-effects meta-analysis [standardized mean difference (SMD)] revealed that AD patients presented lower GABA levels in the brain (SMD = -0.48 [95% CI = -0.7, -0.27], adjusted p value (adj. p) < 0.001) and in the CSF (-0.41 [-0.72, -0.09], adj. p = 0.042), but not in the blood (-0.63 [-1.35, 0.1], adj. p = 0.176). In addition, GAD65/67 (-0.67 [-1.15, -0.2], adj. p = 0.006), GABAA receptor (-0.51 [-0.7, -0.33], adj. p < 0.001), and GABA transporters (-0.51 [-0.92, -0.09], adj. p = 0.016) were lower in the AD brain. Here, we showed a global reduction of GABAergic system components in the brain and lower GABA levels in the CSF of AD patients. Our findings suggest the GABAergic system is vulnerable to AD pathology and should be considered a potential target for developing pharmacological strategies and novel AD biomarkers.
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Affiliation(s)
- Giovanna Carello-Collar
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
| | - Bruna Bellaver
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Pamela C L Ferreira
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - João Pedro Ferrari-Souza
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Vanessa G Ramos
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
| | - Joseph Therriault
- McGill Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada
- Departments of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 1A1, Canada
| | - Cécile Tissot
- McGill Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada
- Departments of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 1A1, Canada
| | - Marco A De Bastiani
- Department of Pharmacology, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
| | - Carolina Soares
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Tharick A Pascoal
- Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
- Department of Neurology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15213, USA
| | - Pedro Rosa-Neto
- McGill Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada
- Departments of Neurology and Neurosurgery, McGill University, Montreal, QC, H3A 1A1, Canada
- Montreal Neurological Institute, McGill University, Montreal, QC, H3A 2B4, Canada
| | - Diogo O Souza
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
- Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil
| | - Eduardo R Zimmer
- Graduate Program in Biological Sciences: Biochemistry, Department of Biochemistry, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil.
- McGill Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada.
- Translational Neuroimaging Laboratory, McGill University Research Centre for Studies in Aging, McGill University, Montreal, QC, H4H 1R3, Canada.
- Department of Pharmacology, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil.
- Graduate Program in Biological Sciences: Pharmacology and Therapeutics, Department of Pharmacology, Institute of Health Basic Sciences, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, RS, 90035-003, Brazil.
- Brain Institute of Rio Grande Do Sul, Pontifical Catholic University of Rio Grande Do Sul, Porto Alegre, RS, 90610-000, Brazil.
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9
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Bernardi S, Gemignani F, Marchese M. The involvement of Purkinje cells in progressive myoclonic epilepsy: Focus on neuronal ceroid lipofuscinosis. Neurobiol Dis 2023; 185:106258. [PMID: 37573956 PMCID: PMC10480493 DOI: 10.1016/j.nbd.2023.106258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 08/01/2023] [Accepted: 08/11/2023] [Indexed: 08/15/2023] Open
Abstract
The progressive myoclonic epilepsies (PMEs) are a group of rare neurodegenerative diseases characterized by myoclonus, epileptic seizures, and progressive neurological deterioration with cerebellar involvement. They include storage diseases like Gaucher disease, Lafora disease, and forms of neuronal ceroid lipofuscinosis (NCL). To date, 13 NCLs have been reported (CLN1-CLN8, CLN10-CLN14), associated with mutations in different genes. These forms, which affect both children and adults, are characterized by seizures, cognitive and motor impairments, and in most cases visual loss. In NCLs, as in other PMEs, central nervous system (CNS) neurodegeneration is widespread and involves different subpopulations of neurons. One of the most affected regions is the cerebellar cortex, where motor and non-motor information is processed and transmitted to deep cerebellar nuclei through the axons of Purkinje cells (PCs). PCs, being GABAergic, have an inhibitory effect on their target neurons, and provide the only inhibitory output of the cerebellum. Degeneration of PCs has been linked to motor impairments and epileptic seizures. Seizures occur when some insult upsets the normal balance in the CNS between excitatory and inhibitory impulses, causing hyperexcitability. Here we review the role of PCs in epilepsy onset and progression following their PME-related loss. In particular, we focus on the involvement of PCs in seizure phenotype in NCLs, highlighting findings from case reports and studies of animal models in which epilepsy can be linked to PC loss.
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Affiliation(s)
- Sara Bernardi
- Department Neurobiology and Molecular Medicine, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy; Department of Biology, University of Pisa, Pisa, Italy
| | | | - Maria Marchese
- Department Neurobiology and Molecular Medicine, IRCCS Fondazione Stella Maris, 56128 Pisa, Italy.
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10
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Maturana W, Lobo I, Landeira-Fernandes J, Mograbi DC. Nondeclarative associative learning in Alzheimer's disease: An overview of eyeblink, fear, and other emotion-based conditioning. Physiol Behav 2023; 268:114250. [PMID: 37224936 DOI: 10.1016/j.physbeh.2023.114250] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 05/04/2023] [Accepted: 05/21/2023] [Indexed: 05/26/2023]
Abstract
Alzheimer's disease is a neurodegenerative disorder that is characterized by progressive cognitive decline, particularly in declarative memory, and the presence of β-amyloid plaques, neurofibrillary tangles, and cortical atrophy (especially in the temporal lobe). Unlike the relationship between the temporal cortex and declarative memory, nondeclarative memories (e.g., motor, fear, and other emotion-based memories) involve distinct neural structures. The present review investigates nondeclarative associative learning ability in Alzheimer's disease. We discuss eyeblink conditioning, fear conditioning, and other emotion-based learning and present the functions and brain areas that are involved in each type of learning. Evidence suggests that nondeclarative learning is also affected by Alzheimer's disease, although some forms of learning may be relatively preserved. Details about each nondeclarative associative learning process and the implications of these findings are presented.
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11
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Sustained Hyperammonemia Activates NF-κB in Purkinje Neurons Through Activation of the TrkB-PI3K-AKT Pathway by Microglia-Derived BDNF in a Rat Model of Minimal Hepatic Encephalopathy. Mol Neurobiol 2023; 60:3071-3085. [PMID: 36790604 DOI: 10.1007/s12035-023-03264-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Accepted: 02/03/2023] [Indexed: 02/16/2023]
Abstract
Chronic hyperammonemia is a main contributor to the cognitive and motor impairment in patients with hepatic encephalopathy. Sustained hyperammonemia induces the TNFα expression in Purkinje neurons, mediated by NF-κB activation. The aims were the following: (1) to assess if enhanced TrkB activation by BDNF is responsible for enhanced NF-κB activation in Purkinje neurons in hyperammonemic rats, (2) to assess if this is associated with increased content of NF-κB modulated proteins such as TNFα, HMGB1, or glutaminase I, (3) to assess if these changes are due to enhanced activation of the TNFR1-S1PR2-CCR2-BDNF-TrkB pathway, (4) to analyze if increased activation of NF-κB is mediated by the PI3K-AKT pathway. It is shown that, in the cerebellum of hyperammonemic rats, increased BDNF levels enhance TrkB activation in Purkinje neurons leading to activation of PI3K, which enhances phosphorylation of AKT and of IκB, leading to increased nuclear translocation of NF-κB which enhances TNFα, HMGB1, and glutaminase I content. To assess if the changes are due to enhanced activation of the TNFR1-S1PR2-CCR2 pathway, we blocked TNFR1 with R7050, S1PR2 with JTE-013, and CCR2 with RS504393. These changes are reversed by blocking TrkB, PI3K, or the TNFR1-SP1PR2-CCL2-CCR2-BDNF-TrkB pathway at any step. In hyperammonemic rats, increased levels of BDNF enhance TrkB activation in Purkinje neurons, leading to activation of the PI3K-AKT-IκB-NF-κB pathway which increased the content of glutaminase I, HMGB1, and TNFα. Enhanced activation of this TrkB-PI3K-AKT-NF-κB pathway would contribute to impairing the function of Purkinje neurons and motor function in hyperammonemic rats and likely in cirrhotic patients with minimal or clinical hepatic encephalopathy.
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12
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Cheron G, Ristori D, Marquez-Ruiz J, Cebolla AM, Ris L. Electrophysiological alterations of the Purkinje cells and deep cerebellar neurons in a mouse model of Alzheimer disease (electrophysiology on cerebellum of AD mice). Eur J Neurosci 2022; 56:5547-5563. [PMID: 35141975 DOI: 10.1111/ejn.15621] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 12/16/2021] [Accepted: 12/19/2021] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease is histopathologically well defined by the presence of amyloid deposits and tau-related neurofibrillary tangles in crucial regions of the brain. Interest is growing in revealing and determining possible pathological markers also in the cerebellum as its involvement in cognitive functions is now well supported. Despite the central position of the Purkinje cell in the cerebellum, its electrophysiological behaviour in mouse models of Alzheimer's disease is scarce in the literature. Our first aim was here to focus on the electrophysiological behaviour of the cerebellum in awake mouse model of Alzheimer's disease (APPswe/PSEN1dE9) and the related performance on the water-maze test classically used in behavioural studies. We found prevalent signs of electrophysiological alterations in both Purkinje cells and deep cerebellar nuclei neurons which might explain the behavioural deficits reported during the water-maze test. The alterations of neurons firing were accompanied by a dual (~16 and ~228 Hz) local field potential's oscillation in the Purkinje cell layer of Alzheimer's disease mice which was concomitant to an important increase of both the simple and the complex spikes. In addition, β-amyloid deposits were present in the molecular layer of the cerebellum. These results highlight the importance of the output firing modification of the AD cerebellum that may indirectly impact the activity of its subcortical and cortical targets.
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Affiliation(s)
- Guy Cheron
- Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles, Brussels, Belgium.,ULB Neuroscience Institut, Université Libre de Bruxelles, Brussels, Belgium.,Laboratory of Neuroscience, Université de Mons, Mons, Belgium
| | - Dominique Ristori
- Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles, Brussels, Belgium
| | - Javier Marquez-Ruiz
- Department of Physiology, Anatomy and Cell Biology, Pablo de Olavide University, Seville, Spain
| | - Anna-Maria Cebolla
- Laboratory of Neurophysiology and Movement Biomechanics, Université Libre de Bruxelles, Brussels, Belgium
| | - Laurence Ris
- Laboratory of Neuroscience, Université de Mons, Mons, Belgium.,UMONS Research Institut for health and technology, Université de Mons, Mons, Belgium
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13
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Hassan HM, Elnagar MR, Abdelrazik E, Mahdi MR, Hamza E, Elattar EM, ElNashar EM, Alghamdi MA, Al-Qahtani Z, Al-Khater KM, Aldahhan RA, ELdesoqui M. Neuroprotective effect of naringin against cerebellar changes in Alzheimer's disease through modulation of autophagy, oxidative stress and tau expression: An experimental study. Front Neuroanat 2022; 16:1012422. [PMID: 36312298 PMCID: PMC9615142 DOI: 10.3389/fnana.2022.1012422] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Accepted: 09/26/2022] [Indexed: 11/13/2022] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder characterized by gradual cognitive decline. Strong antioxidants that inhibit free radicals, such as polyphenols, reduce the likelihood of developing oxidative stress-related degenerative diseases such as AD. Naringin, a flavonoid found in citrus fruit shown to be neuroprotective, reduce oxidative damage and minimize histopathological changes caused by ischemic reperfusion, enhance the long-term memory in AD animal models. This work aimed to comprehend the role of naringin in the defense of the cerebellum against aluminum chloride (AlCl3)-induced AD in rats by investigating the behavioral, neurochemical, immunohistochemical, and molecular mechanisms that underpin its possible neuroprotective effects. Twenty-four adult albino rats were divided into four groups (n = 6/group): (i) Control (C) received saline per oral (p.o.), (ii) Naringin(N)-received naringin (100 mg/kg/d) p.o, (iii) AlCl3-recived AlCl3 (100 mg/kg/d) p.o and (iv) AlCl3 + Naringin (AlCl3 + N) received both AlCl3 and naringin p.o for 21 days. Behavioral tests showed an increase in the time to reach the platform in Morris water maze, indicating memory impairment in the AlCl3-treated group, but co-administration of naringin showed significant improvement. The Rotarod test demonstrated a decrease in muscle coordination in the AlCl3-treated group, while it was improved in the AlCl3 + N group. Neurochemical analysis of the hippocampus and cerebellum revealed that AlCl3 significantly increased lipid peroxidation and oxidative stress and decreased levels of reduced glutathione. Administration of naringin ameliorated these neurochemical changes via its antioxidant properties. Cerebellar immunohistochemical expression for microtubule assembly (tau protein) and oxidative stress (iNOS) increased in A1C13-treated group. On the other hand, the expression of the autophagic marker (LC3) in the cerebellum showed a marked decline in AlCl3-treated group. Western blot analysis confirmed the cerebellar immunohistochemical findings. Collectively, these findings suggested that naringin could contribute to the combat of oxidative and autophagic stress in the cerebellum of AlCl3-induced AD.
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Affiliation(s)
- Hend M. Hassan
- Department of Human Anatomy and Embryology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Mohamed R. Elnagar
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Al-Azhar University, Cairo, Egypt
- Department of Pharmacology, College of Pharmacy, The Islamic University, Najaf, Iraq
| | - Eman Abdelrazik
- Department of Forensic Medicine and Clinical Toxicology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Mohamed R. Mahdi
- Department of Human Anatomy and Embryology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
| | - Eman Hamza
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
- Department of Medical Biochemistry and Molecular Biology, Faculty of Medicine, Horus University, Damietta, Egypt
| | - Eman M. Elattar
- Department of Pharmacognosy, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt
| | - Eman Mohamed ElNashar
- Department of Anatomy, College of Medicine, King Khalid University, Abha, Saudi Arabia
- Department of Histology and Cell Biology, Faculty of Medicine, Benha University, Banha, Egypt
| | - Mansour Abdullah Alghamdi
- Department of Anatomy, College of Medicine, King Khalid University, Abha, Saudi Arabia
- Genomics and Personalized Medicine Unit, College of Medicine, King Khalid University, Abha, Saudi Arabia
| | - Zainah Al-Qahtani
- Neurology Section, Department of Internal Medicine, College of Medicine, King Khalid University, Abha, Saudi Arabia
| | - Khulood Mohammed Al-Khater
- Department of Anatomy, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Rashid A. Aldahhan
- Department of Anatomy, College of Medicine, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia
| | - Mamdouh ELdesoqui
- Department of Human Anatomy and Embryology, Faculty of Medicine, Mansoura University, Mansoura, Egypt
- Department of Basic Medical Sciences, College of Medicine, AlMaarefa University, Riyadh, Saudi Arabia
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14
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Pandey S. Is essential tremor a family of diseases or a syndrome? A syndrome. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2022; 163:31-59. [PMID: 35750367 DOI: 10.1016/bs.irn.2022.02.002] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
In a consensus statement, a task force of the "International Parkinson and Movement Disorder Society" (IPMDS) has recently proposed a two axes classification for tremor: axis I (clinical manifestations) and axis II (etiology). In the axis, I, the clinical features of tremor in a given patient are specified in terms of medical history, tremor characteristics, associated signs, and laboratory tests for some tremors leading to the discovery of axis 2 etiologies. Based on axis I sign and symptoms a specific clinical syndrome is diagnosed which have been categorized as isolated tremor syndrome (a syndrome consisting only of tremor) and combined tremor syndrome (consisting of tremor and other systemic or neurological signs). The IPMDS task force defined essential tremor as an isolated tremor syndrome of bilateral upper limb action tremor of at least 3years duration with or without a tremor in other locations (e.g., head, voice or lower limbs) in absence of other neurological signs, such as dystonia, ataxia, or parkinsonism. Patients with neurological signs of uncertain significance (such as impaired tandem gait, questionable dystonic posturing, or memory impairment) are classified as essential tremor plus. In this paper, the author will make the argument that essential tremor is a syndrome with multiple causes.
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Affiliation(s)
- Sanjay Pandey
- Department of Neurology, Govind Ballabh Pant Postgraduate Institute of Medical Education and Research, New Delhi, India.
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15
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Kulminski AM, Loiko E, Loika Y, Culminskaya I. Pleiotropic predisposition to Alzheimer's disease and educational attainment: insights from the summary statistics analysis. GeroScience 2022; 44:265-280. [PMID: 34743297 PMCID: PMC8572080 DOI: 10.1007/s11357-021-00484-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Accepted: 10/28/2021] [Indexed: 12/25/2022] Open
Abstract
Epidemiological studies report beneficial associations of higher educational attainment (EDU) with Alzheimer's disease (AD). Prior genome-wide association studies (GWAS) also reported variants associated with AD and EDU separately. The analysis of pleiotropic associations with these phenotypes may shed light on EDU-related protection against AD. We performed pleiotropic meta-analyses using Fisher's method and omnibus test applied to summary statistics for single nucleotide polymorphisms (SNPs) associated with AD and EDU in large-scale univariate GWAS at suggestive-effect (5 × 10-8 < p < 0.1) and genome-wide (p ≤ 5 × 10-8) significance levels. We report 53 SNPs that attained p ≤ 5 × 10-8 at least in one of the pleiotropic meta-analyses and were reported in the univariate GWAS at 5 × 10-8 < p < 0.1. Of them, there were 46 pleiotropic SNPs according to Fisher's method. Additionally, Fisher's method identified 25 of 206 SNPs with pleiotropic effects, which attained p ≤ 5 × 10-8 in the univariate GWAS. We showed that a large fraction of the pleiotropic associations was affected by a counterintuitive phenomenon of antagonistic genetic heterogeneity, which explains the increase, rather than decrease, of the significance of the pleiotropic associations in the omnibus test. Functional enrichment analysis showed that apart from cancers, gene set harboring the non-pleiotropic SNPs was characterized by late-onset AD and neurodevelopmental disorders. The pleiotropic gene set was characterized by a broad spectrum of progressive neurological and neuromuscular diseases and immune-mediated conditions, including progressive motor neuropathy, multiple sclerosis, Parkinson's disease, and severe AD. Our results suggest that disentangling genes harboring variants with and without pleiotropic associations with AD and EDU is promising for dissecting heterogeneity in biological mechanisms of AD.
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Affiliation(s)
- Alexander M Kulminski
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, 27708-0408, USA.
| | - Elena Loiko
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, 27708-0408, USA
| | - Yury Loika
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, 27708-0408, USA
| | - Irina Culminskaya
- Biodemography of Aging Research Unit, Social Science Research Institute, Duke University, Durham, NC, 27708-0408, USA
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16
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Buchberger A, Schepergerdes L, Flaßhoff M, Kunick C, Köster RW. A novel inhibitor rescues cerebellar defects in a zebrafish model of Down syndrome-associated kinase Dyrk1A overexpression. J Biol Chem 2021; 297:100853. [PMID: 34090874 PMCID: PMC8239740 DOI: 10.1016/j.jbc.2021.100853] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 05/25/2021] [Accepted: 06/02/2021] [Indexed: 12/31/2022] Open
Abstract
The highly conserved dual-specificity tyrosine phosphorylation-regulated kinase 1A (Dyrk1A) plays crucial roles during central nervous system development and homeostasis. Furthermore, its hyperactivity is considered responsible for some neurological defects in individuals with Down syndrome. We set out to establish a zebrafish model expressing human Dyrk1A that could be further used to characterize the interaction between Dyrk1A and neurological phenotypes. First, we revealed the prominent expression of dyrk1a homologs in cerebellar neurons in the zebrafish larval and adult brains. Overexpression of human dyrk1a in postmitotic cerebellar Purkinje neurons resulted in a structural misorganization of the Purkinje cells in cerebellar hemispheres and a compaction of this cell population. This impaired Purkinje cell organization was progressive, leading to an age-dependent dispersal of Purkinje neurons throughout the cerebellar molecular layer with larval swim deficits resulting in miscoordination of swimming and reduced exploratory behavior in aged adults. We also found that the structural misorganization of the larval Purkinje cell layer could be rescued by pharmacological treatment with Dyrk1A inhibitors. We further reveal the in vivo efficiency of a novel selective Dyrk1A inhibitor, KuFal194. These findings demonstrate that the zebrafish is a well-suited vertebrate organism to genetically model severe neurological diseases with single cell type specificity. Such models can be used to relate molecular malfunction to cellular deficits, impaired tissue formation, and organismal behavior and can also be used for pharmacological compound testing and validation.
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Affiliation(s)
- Astrid Buchberger
- Division of Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Lena Schepergerdes
- Division of Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany
| | - Maren Flaßhoff
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany
| | - Conrad Kunick
- Institute of Medicinal and Pharmaceutical Chemistry, Technische Universität Braunschweig, Braunschweig, Germany; Center of Pharmaceutical Engineering (PVZ), Technische Universität Braunschweig, Braunschweig, Germany
| | - Reinhard W Köster
- Division of Cellular and Molecular Neurobiology, Zoological Institute, Technische Universität Braunschweig, Braunschweig, Germany.
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17
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Miguel JC, Perez SE, Malek-Ahmadi M, Mufson EJ. Cerebellar Calcium-Binding Protein and Neurotrophin Receptor Defects in Down Syndrome and Alzheimer's Disease. Front Aging Neurosci 2021; 13:645334. [PMID: 33776745 PMCID: PMC7994928 DOI: 10.3389/fnagi.2021.645334] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 02/04/2021] [Indexed: 12/11/2022] Open
Abstract
Cerebellar hypoplasia is a major characteristic of the Down syndrome (DS) brain. However, the consequences of trisomy upon cerebellar Purkinje cells (PC) and interneurons in DS are unclear. The present study performed a quantitative and qualitative analysis of cerebellar neurons immunostained with antibodies against calbindin D-28k (Calb), parvalbumin (Parv), and calretinin (Calr), phosphorylated and non-phosphorylated intermediate neurofilaments (SMI-34 and SMI-32), and high (TrkA) and low (p75NTR) affinity nerve growth factor (NGF) receptors as well as tau and amyloid in DS (n = 12), Alzheimer's disease (AD) (n = 10), and healthy non-dementia control (HC) (n = 8) cases. Our findings revealed higher Aβ42 plaque load in DS compared to AD and HC but no differences in APP/Aβ plaque load between HC, AD, and DS. The cerebellar cortex neither displayed Aβ40 containing plaques nor pathologic phosphorylated tau in any of the cases examined. The number and optical density (OD) measurements of Calb immunoreactive (-ir) PC soma and dendrites were similar between groups, while the number of PCs positive for Parv and SMI-32 were significantly reduced in AD and DS compared to HC. By contrast, the number of SMI-34-ir PC dystrophic axonal swellings, termed torpedoes, was significantly greater in AD compared to DS. No differences in SMI-32- and Parv-ir PC OD measurements were observed between groups. Conversely, total number of Parv- (stellate/basket) and Calr (Lugaro, brush, and Golgi)-positive interneurons were significantly reduced in DS compared to AD and HC. A strong negative correlation was found between counts for Parv-ir interneurons, Calr-ir Golgi and brush cells, and Aβ42 plaque load. Number of TrkA and p75NTR positive PCs were reduced in AD compared to HC. These findings suggest that disturbances in calcium binding proteins play a critical role in cerebellar neuronal dysfunction in adults with DS.
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Affiliation(s)
- Jennifer C. Miguel
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Sylvia E. Perez
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States
| | - Michael Malek-Ahmadi
- Department of Biomedical Informatics, Banner Alzheimer's Institute, Phoenix, AZ, United States
| | - Elliott J. Mufson
- Department of Neurobiology, Barrow Neurological Institute, Phoenix, AZ, United States
- Department of Neurology, Barrow Neurological Institute, Phoenix, AZ, United States
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18
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Chaudhari K, Wang L, Kruse J, Winters A, Sumien N, Shetty R, Prah J, Liu R, Shi J, Forster M, Yang SH. Early loss of cerebellar Purkinje cells in human and a transgenic mouse model of Alzheimer's disease. Neurol Res 2021; 43:570-581. [PMID: 33688799 DOI: 10.1080/01616412.2021.1893566] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
BACKGROUND The cerebellum's involvement in AD has been under-appreciated by historically labeling as a normal control in AD research. METHODS We determined the involvement of the cerebellum in AD progression. Postmortem human and APPswe/PSEN1dE9 mice cerebellums were used to assess the cerebellar Purkinje cells (PC) by immunohistochemistry. The locomotor and spatial cognitive functions were assessed in 4- to 5-month-old APPswe/PSEN1dE9 mice. Aβ plaque and APP processing were determined in APPswe/PSEN1dE9 mice at different age groups by immunohistochemistry and Western blot. RESULTS We observed loss of cerebellar PC in mild cognitive impairment and AD patients compared with cognitively normal controls. A strong trend towards PC loss was found in AD mice as early as 5 months. Impairment of balance beam and rotorod performance, but no spatial learning and memory dysfunction was observed in AD mice at 4-5 months. Aβ plaque in the cerebral cortex was evidenced in AD mice at 2 months and dramatically increased at 6 months. Less and smaller Aβ plaques were observed in the cerebellum than in the cerebrum of AD mice. Similar intracellular APP staining was observed in the cerebellum and cerebrum of AD mice at 2 to 10 months. Similar expression of full-length APP and C-terminal fragments were indicated in the cerebrum and cerebellum of AD mice during aging. DISCUSSION Our study in post-mortem human brains and transgenic AD mice provided neuropathological and functional evidence that cerebellar dysfunction may occur at the early stage of AD and likely independent of Aβ plaque.
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Affiliation(s)
- Kiran Chaudhari
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Linshu Wang
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Jonas Kruse
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Ali Winters
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Nathalie Sumien
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Ritu Shetty
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Jude Prah
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Ran Liu
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Jiong Shi
- Lou Ruvo Center for Brain Health, Cleveland Clinic Nevada, 888 W Bonneville Avenue, Las Vegas, NV USA
| | - Michael Forster
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
| | - Shao-Hua Yang
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, TX USA
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19
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Fitzgerald M, Pritschet L, Santander T, Grafton ST, Jacobs EG. Cerebellar network organization across the human menstrual cycle. Sci Rep 2020; 10:20732. [PMID: 33244032 PMCID: PMC7691518 DOI: 10.1038/s41598-020-77779-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 11/17/2020] [Indexed: 11/09/2022] Open
Abstract
The cerebellum contains the vast majority of neurons in the brain and houses distinct functional networks that constitute at least two homotopic maps of cerebral networks. It is also a major site of sex steroid hormone action. While the functional organization of the human cerebellum has been characterized, the influence of sex steroid hormones on intrinsic cerebellar network dynamics has yet to be established. Here we investigated the extent to which endogenous fluctuations in estradiol and progesterone alter functional cerebellar networks at rest in a woman densely sampled over a complete menstrual cycle (30 consecutive days). Edgewise regression analysis revealed robust negative associations between progesterone and cerebellar coherence. Graph theory metrics probed sex hormones' influence on topological brain states, revealing relationships between sex hormones and within-network integration in Ventral Attention, Dorsal Attention, and SomatoMotor Networks. Together these results suggest that the intrinsic dynamics of the cerebellum are intimately tied to day-by-day changes in sex hormones.
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Affiliation(s)
- Morgan Fitzgerald
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Laura Pritschet
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Tyler Santander
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
| | - Scott T Grafton
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA
- Institute for Collaborative Biotechnologies, University of California, Santa Barbara, USA
- Neuroscience Research Institute, University of California, Santa Barbara, USA
| | - Emily G Jacobs
- Department of Psychological and Brain Sciences, University of California, Santa Barbara, Santa Barbara, CA, 93106, USA.
- Neuroscience Research Institute, University of California, Santa Barbara, USA.
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20
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Kärkkäinen M, Prakash M, Zare M, Tohka J, for the Alzheimer's Disease Neuroimaging Initiative. Structural Brain Imaging Phenotypes of Mild Cognitive Impairment (MCI) and Alzheimer's Disease (AD) Found by Hierarchical Clustering. Int J Alzheimers Dis 2020; 2020:2142854. [PMID: 33299603 PMCID: PMC7708019 DOI: 10.1155/2020/2142854] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Revised: 05/27/2020] [Accepted: 06/29/2020] [Indexed: 11/27/2022] Open
Abstract
A hierarchical clustering algorithm was applied to magnetic resonance images (MRI) of a cohort of 751 subjects having a mild cognitive impairment (MCI), 282 subjects having received Alzheimer's disease (AD) diagnosis, and 428 normal controls (NC). MRIs were preprocessed to gray matter density maps and registered to a stereotactic space. By first rendering the gray matter density maps comparable by regressing out age, gender, and years of education, and then performing the hierarchical clustering, we found clusters displaying structural features of typical AD, cortically-driven atypical AD, limbic-predominant AD, and early-onset AD (EOAD). Among these clusters, EOAD subjects displayed marked cortical gray matter atrophy and atrophy of the precuneus. Furthermore, EOAD subjects had the highest progression rates as measured with ADAS slopes during the longitudinal follow-up of 36 months. Striking heterogeneities in brain atrophy patterns were observed with MCI subjects. We found clusters of stable MCI, clusters of diffuse brain atrophy with fast progression, and MCI subjects displaying similar atrophy patterns as the typical or atypical AD subjects. Bidirectional differences in structural phenotypes were found with MCI subjects involving the anterior cerebellum and the frontal cortex. The diversity of the MCI subjects suggests that the structural phenotypes of MCI subjects would deserve a more detailed investigation with a significantly larger cohort. Our results demonstrate that the hierarchical agglomerative clustering method is an efficient tool in dividing a cohort of subjects with gray matter atrophy into coherent clusters manifesting different structural phenotypes.
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Affiliation(s)
- Mikko Kärkkäinen
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Mithilesh Prakash
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
| | - Marzieh Zare
- Signal Processing, Tampere University, Tampere, Finland
| | - Jussi Tohka
- A.I. Virtanen Institute for Molecular Sciences, University of Eastern Finland, Kuopio, Finland
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21
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Bolaños-Burgos IC, Bernal-Correa AM, Mahecha GAB, Ribeiro ÂM, Kushmerick C. Thiamine Deficiency Increases Intrinsic Excitability of Mouse Cerebellar Purkinje Cells. THE CEREBELLUM 2020; 20:186-202. [PMID: 33098550 DOI: 10.1007/s12311-020-01202-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 10/08/2020] [Indexed: 10/23/2022]
Abstract
Thiamine deficiency is associated with cerebellar dysfunction; however, the consequences of thiamine deficiency on the electrophysiological properties of cerebellar Purkinje cells are poorly understood. Here, we evaluated these parameters in brain slices containing cerebellar vermis. Adult mice were maintained for 12-13 days on a thiamine-free diet coupled with daily injections of pyrithiamine, an inhibitor of thiamine phosphorylation. Morphological analysis revealed a 20% reduction in Purkinje cell and nuclear volume in thiamine-deficient animals compared to feeding-matched controls, with no reduction in cell count. Under whole-cell current clamp, thiamine-deficient Purkinje cells required significantly less current injection to fire an action potential. This reduction in rheobase was not due to a change in voltage threshold. Rather, thiamine-deficient neurons presented significantly higher input resistance specifically in the voltage range just below threshold, which increases their sensitivity to current at these critical membrane potentials. In addition, thiamine deficiency caused a significant decrease in the amplitude of the action potential afterhyperpolarization, broadened the action potential, and decreased the current threshold for depolarization block. When thiamine-deficient animals were allowed to recover for 1 week on a normal diet, rheobase, threshold, action potential half-width, and depolarization block threshold were no longer different from controls. We conclude that thiamine deficiency causes significant but reversible changes to the electrophysiology properties of Purkinje cells prior to pathological morphological alterations or cell loss. Thus, the data obtained in the present study indicate that increased excitability of Purkinje cells may represent a leading indicator of cerebellar dysfunction caused by lack of thiamine.
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Affiliation(s)
| | - Ana María Bernal-Correa
- Graduate Program in Physiology and Pharmacology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Ângela Maria Ribeiro
- Graduate Program in Neuroscience, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.,Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Christopher Kushmerick
- Graduate Program in Neuroscience, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. .,Graduate Program in Physiology and Pharmacology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil. .,Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil.
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22
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Elble RJ. Do We Belittle Essential Tremor by Calling It a Syndrome Rather Than a Disease? No. Front Neurol 2020; 11:586606. [PMID: 33101188 PMCID: PMC7554602 DOI: 10.3389/fneur.2020.586606] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/26/2020] [Indexed: 12/16/2022] Open
Abstract
A task force of the International Parkinson and Movement Disorder Society (MDS) recently published a tremor classification scheme that is based on the nosologic principle of two primary axes for classifying an illness: clinical manifestations (Axis 1) and etiology (Axis 2). An Axis 1 clinical syndrome is a recurring group of clinical symptoms, signs (physical findings), and possibly laboratory results that suggests the presence of at least one underlying Axis 2 etiology. Syndromes must be defined and used consistently to be of value in finding specific etiologies and effective treatments. The MDS task force concluded that essential tremor is a common neurological syndrome that has never been defined consistently by clinicians and researchers. The MDS task force defined essential tremor as a syndrome of bilateral upper limb action tremor of at least 3 years duration, with or without tremor in other locations (e.g., head, voice, or lower limbs), in the absence of other neurological signs (e.g., dystonia, parkinsonism, myoclonus, ataxia, peripheral neuropathy, and cognitive impairment). Deviations from this definition should not be labeled as essential tremor. Patients with additional questionably-abnormal signs or with signs of uncertain relevance to tremor are classified as essential tremor plus. The MDS classification scheme encourages a thorough unbiased phenotyping of patients with tremor, with no assumptions of etiology, pathology, pathophysiology, or relationship to other neurological disorders. The etiologies, pathology, and clinical course of essential tremor are too heterogeneous for this syndrome to be viewed as a disease or a family of diseases.
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Affiliation(s)
- Rodger J Elble
- Department of Neurology, Southern Illinois University School of Medicine, Springfield, IL, United States
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