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Li M, Flack N, Larsen PA. Multifaceted impact of specialized neuropeptide-intensive neurons on the selective vulnerability in Alzheimer's disease. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.13.566905. [PMID: 38014130 PMCID: PMC10680689 DOI: 10.1101/2023.11.13.566905] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
INTRODUCTION Widespread disruption of neuropeptide (NP) networks in Alzheimer's disease (AD) and disproportionate absence of neurons expressing high NP-producing, coined as HNP neurons, have been reported for the entorhinal cortex (EC) of AD brains. Hypothesizing that functional features of HNP neurons are involved in the early pathogenesis of AD, we aim to understand the molecular mechanisms underlying these observations. METHODS Multiscale and spatiotemporal transcriptomic analysis was used to investigate AD-afflicted and healthy brains. Our focus encompassed NP expression dynamics in AD, AD-associated NPs (ADNPs) trajectories with aging, and the neuroanatomical distribution of HNP neuron. RESULTS Findings include that 1) HNP neurons exhibited heightened metabolic needs and an upregulation of gene expressions linked to protein misfolding; 2) dysfunctions of ADNP production occurred in aging and mild cognitive decline; 3) HNP neurons co-expressing ADNPs were preferentially distributed in brain regions susceptible to AD. DISCUSSION We identified potential mechanisms that contribute to the selective vulnerability of HNP neurons to AD. Our results indicate that the functions of HNP neurons predispose them to oxidative stress and protein misfolding, potentially serving as inception sites for misfolded proteins in AD.
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Affiliation(s)
- Manci Li
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108
- Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul MN 55108
| | - Nichole Flack
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108
- Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul MN 55108
| | - Peter A. Larsen
- Department of Veterinary and Biomedical Sciences, University of Minnesota, St. Paul, MN 55108
- Minnesota Center for Prion Research and Outreach, College of Veterinary Medicine, University of Minnesota, St. Paul MN 55108
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Khlif MS, Werden E, Bird LJ, Egorova-Brumley N, Brodtmann A. Atrophy of Ipsilesional Hippocampal Subfields Vary Over First Year After Ischemic Stroke. J Magn Reson Imaging 2021; 56:273-281. [PMID: 34837426 DOI: 10.1002/jmri.28009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2021] [Revised: 11/15/2021] [Accepted: 11/17/2021] [Indexed: 11/05/2022] Open
Abstract
BACKGROUND The structural integrity of hippocampal subfields has been investigated in many neurological disorders and was shown to be better associated with cognitive performance than whole hippocampus. In stroke, hippocampal atrophy is linked to cognitive impairment, but it is unknown whether the hippocampal subfields atrophy differently. PURPOSE To evaluate longitudinal hippocampal subfield atrophy in first year poststroke, in comparison with atrophy in healthy individuals. STUDY TYPE Cohort. SUBJECTS A total of 92 ischemic stroke (age: 67 ± 12 years, 63 men) and 39 healthy participants (age: 69 ± 7 years, 24 men). FIELD STRENGTH/SEQUENCE A3 T/T1-MPRAGE, T2-SPACE, and T2-FLAIR. ASSESSMENT FreeSurfer (6.0) was used to delineate 12 hippocampal subfields. Whole hippocampal volume was computed as sum of subfield volumes excluding hippocampal fissure volume. Separate assessments were completed for contralesional and ipsilesional hippocampi. STATISTICAL TESTS A mixed-effect regression model was used to compare subfield volumes cross-sectionally between healthy and stroke groups and longitudinally between 3-month and 12-month timepoints. False discovery rate at 0.05 significance level was used to correct for multiple comparisons. Also, a receiver operating characteristic (ROC) curve analysis was performed to assess differentiation between healthy and stroke participants based on subfield volumes. RESULTS There were no volume differences between groups at 3 months, but there was a significant difference (P = 0.027) in whole hippocampal volume reduction over time between control and stroke ipsilesionally. Thus, the ipsilesional whole hippocampal volume in stroke became significantly smaller (P = 0.035) at 12 months. The hippocampal tail was the highest single-region contributor (22.7%) to ipsilesional hippocampal atrophy (1.19%) over 9 months. The cornu ammonis areas (CA1) subfield volume reduction was minimal in controls and stroke contralesionally but significant ipsilesionally (P = 0.007). CA1 volume significantly outperformed whole hippocampal volume (P < 0.01) in discriminating between stroke participants and healthy controls in ROC curve analysis. DATA CONCLUSION Greater stroke-induced effects were observed in the ipsilesional hippocampus anteriorly in CA1 and posteriorly in the hippocampal tail. Atrophy of CA1 and hippocampal tail may provide a better link to cognitive impairment than whole hippocampal atrophy. LEVEL OF EVIDENCE 2 TECHNICAL EFFICACY STAGE: 3.
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Affiliation(s)
- Mohamed Salah Khlif
- The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Emilio Werden
- The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Laura J Bird
- The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia
| | - Natalia Egorova-Brumley
- The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.,Melbourne School of Psychological Sciences, University of Melbourne, Melbourne, Australia
| | - Amy Brodtmann
- The Florey Institute for Neuroscience and Mental Health, University of Melbourne, Melbourne, Australia.,Department of Neurology, Austin Health, Heidelberg, Victoria, Australia.,Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia.,Eastern Cognitive Disorders Clinic, Box Hill Hospital, Monash University, Box Hill, Victoria, Australia
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Morton H, Kshirsagar S, Orlov E, Bunquin LE, Sawant N, Boleng L, George M, Basu T, Ramasubramanian B, Pradeepkiran JA, Kumar S, Vijayan M, Reddy AP, Reddy PH. Defective mitophagy and synaptic degeneration in Alzheimer's disease: Focus on aging, mitochondria and synapse. Free Radic Biol Med 2021; 172:652-667. [PMID: 34246776 DOI: 10.1016/j.freeradbiomed.2021.07.013] [Citation(s) in RCA: 76] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/18/2021] [Revised: 06/06/2021] [Accepted: 07/06/2021] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disease characterized by memory loss and multiple cognitive impairments. AD is marked by multiple cellular changes, including deregulation of microRNAs, activation of glia and astrocytes, hormonal imbalance, defective mitophagy, synaptic degeneration, in addition to extracellular neuritic amyloid-beta (Aβ) plaques, phosphorylated tau (P-tau), and intracellular neurofibrillary tangles (NFTs). Recent research in AD revealed that defective synaptic mitophagy leads to synaptic degeneration and cognitive dysfunction in AD neurons. Our critical analyses of mitochondria and Aβ and P-tau revealed that increased levels of Aβ and P-Tau, and abnormal interactions between Aβ and Drp1, P-Tau and Drp1 induced increased mitochondrial fragmentation and proliferation of dysfunctional mitochondria in AD neurons and depleted Parkin and PINK1 levels. These events ultimately lead to impaired clearance of dead and/or dying mitochondria in AD neurons. The purpose of our article is to highlight the recent research on mitochondria and synapses in relation to Aβ and P-tau, focusing on recent developments.
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Affiliation(s)
- Hallie Morton
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Sudhir Kshirsagar
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Erika Orlov
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Lloyd E Bunquin
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Neha Sawant
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Lauren Boleng
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Nutritional Sciences Nutritional Science, College of Human Sciences, Texas Tech University, 1301Akron Ave, Lubbock, TX, 79409, USA
| | - Mathew George
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Tanisha Basu
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | | | | | - Subodh Kumar
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Murali Vijayan
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA
| | - Arubala P Reddy
- Nutritional Sciences Nutritional Science, College of Human Sciences, Texas Tech University, 1301Akron Ave, Lubbock, TX, 79409, USA
| | - P Hemachandra Reddy
- Department of Internal Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neuroscience & Pharmacology, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Neurology, Departments of School of Medicine, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Public Health Department of Graduate School of Biomedical Sciences, Texas Tech University Health Sciences Center, Lubbock, TX, USA; Department of Speech, Language and Hearing Sciences, School Health Professions, Texas Tech University Health Sciences Center, Lubbock, TX, USA.
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Olsen RK, Carr VA, Daugherty AM, La Joie R, Amaral RS, Amunts K, Augustinack JC, Bakker A, Bender AR, Berron D, Boccardi M, Bocchetta M, Burggren AC, Chakravarty MM, Chételat G, de Flores R, DeKraker J, Ding SL, Geerlings MI, Huang Y, Insausti R, Johnson EG, Kanel P, Kedo O, Kennedy KM, Keresztes A, Lee JK, Lindenberger U, Mueller SG, Mulligan EM, Ofen N, Palombo DJ, Pasquini L, Pluta J, Raz N, Rodrigue KM, Schlichting ML, Lee Shing Y, Stark CE, Steve TA, Suthana NA, Wang L, Werkle-Bergner M, Yushkevich PA, Yu Q, Wisse LE. Progress update from the hippocampal subfields group. ALZHEIMER'S & DEMENTIA (AMSTERDAM, NETHERLANDS) 2019; 11:439-449. [PMID: 31245529 PMCID: PMC6581847 DOI: 10.1016/j.dadm.2019.04.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Heterogeneity of segmentation protocols for medial temporal lobe regions and hippocampal subfields on in vivo magnetic resonance imaging hinders the ability to integrate findings across studies. We aim to develop a harmonized protocol based on expert consensus and histological evidence. METHODS Our international working group, funded by the EU Joint Programme-Neurodegenerative Disease Research (JPND), is working toward the production of a reliable, validated, harmonized protocol for segmentation of medial temporal lobe regions. The working group uses a novel postmortem data set and online consensus procedures to ensure validity and facilitate adoption. RESULTS This progress report describes the initial results and milestones that we have achieved to date, including the development of a draft protocol and results from the initial reliability tests and consensus procedures. DISCUSSION A harmonized protocol will enable the standardization of segmentation methods across laboratories interested in medial temporal lobe research worldwide.
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Affiliation(s)
- Rosanna K. Olsen
- Rotman Research Institute, Baycrest Health Sciences, Toronto, Ontario, Canada
- Department of Psychology, University of Toronto, Toronto, Ontario, Canada
| | - Valerie A. Carr
- Department of Psychology, San Jose State University, San Jose, CA, USA
| | - Ana M. Daugherty
- Department of Psychology, Wayne State University, Detroit, MI, USA
- Department of Psychiatry and Behavioral Neurosciences, Wayne State University, Detroit, MI, USA
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
| | - Renaud La Joie
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - Robert S.C. Amaral
- Cerebral Imaging Centre, Douglas Hospital Mental Health University Institute, Verdun, Quebec, Canada
| | - Katrin Amunts
- C. and O. Vogt Institute for Brain Research, Medical Faculty, University Hospital Düsseldorf, Düsseldorf, Germany
- Heinrich Heine University Düsseldorf, Düsseldorf, Germany
- Institute of Neuroscience and Medicine (INM-1), Research Centre Jülich, Jülich, Germany
| | - Jean C. Augustinack
- Department of Radiology, Harvard Medical School, Charlestown, MA, USA
- Massachusetts General Hospital, Charlestown, MA, USA
| | - Arnold Bakker
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Andrew R. Bender
- Department of Epidemiology and Biostatistics, Michigan State University, East Lansing, MI, USA
- Department of Neurology and Ophthalmology, Michigan State University, East Lansing, MI, USA
- College of Human Medicine, Michigan State University, East Lansing, MI, USA
| | - David Berron
- Clinical Memory Research Unit, Department of Clinical Sciences Malmö, Lund University, Lund, Sweden
- German Center for Neurodegenerative Diseases (DZNE), Magdeburg, Germany
| | - Marina Boccardi
- Department of Psychiatry, University of Geneva, Geneva, Switzerland
- IRCCS Centro San Giovanni di Dio Fatebenefratelli, Brescia, Italy
| | - Martina Bocchetta
- Dementia Research Centre, Department of Neurodegenerative Disease, University College London, London, United Kingdom
| | - Alison C. Burggren
- Robert and Beverly Lewis Center for Neuroimaging, University of Oregon, Eugene, OR, USA
| | - M. Mallar Chakravarty
- Cerebral Imaging Centre, Douglas Hospital Mental Health University Institute, Verdun, Quebec, Canada
- Department of Psychiatry, McGill University, Montreal, Quebec, Canada
- Department of Biological and Biomedical Engineering, McGill University, Montreal, Quebec, Canada
| | - Gaël Chételat
- Université Normandie, Université de Caen-Normandie, Caen, France
- Institut National de la Santé et de la Recherché Médicale (INSERM), UMR-S U1237, Caen, France
- GIP Cyceron, Caen, France
| | - Robin de Flores
- Université Normandie, Université de Caen-Normandie, Caen, France
- Institut National de la Santé et de la Recherché Médicale (INSERM), UMR-S U1237, Caen, France
| | - Jordan DeKraker
- Robarts Research Institute, Brain and Mind Institute, University of Western Ontario, London, Ontario, Canada
| | | | - Mirjam I. Geerlings
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Utrecht, The Netherlands
- Utrecht University, Utrecht, The Netherlands
| | - Yushan Huang
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - Ricardo Insausti
- Human Neuroanatomy Laboratory, University of Castilla-La Mancha, Albacete, Spain
| | | | - Prabesh Kanel
- Department of Radiology at the University of Michigan, Ann Arbor, MI, USA
| | - Olga Kedo
- Heinrich Heine University Düsseldorf, Düsseldorf, Germany
| | - Kristen M. Kennedy
- Center for Vital Longevity, Behavioral and Brain Science, The University of Texas at Dallas, Dallas, TX, USA
| | - Attila Keresztes
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Joshua K. Lee
- Center for Mind and Brain, University of California, Davis, CA, USA
- Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Davis, CA, USA
| | - Ulman Lindenberger
- Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
- Max Planck – University College London Centre for Computational Psychiatry and Ageing Research, Berlin, Germany and London, United Kingdom
| | - Susanne G. Mueller
- Department of Radiology, University of California, San Francisco, CA, USA
| | | | - Noa Ofen
- Department of Psychology, Wayne State University, Detroit, MI, USA
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
- Neurobiology Department, Weizmann Institute of Science, Rehovot, Israel
| | - Daniela J. Palombo
- Department of Psychology, University of British Columbia, Vancouver, British Colombia, Canada
| | - Lorenzo Pasquini
- Department of Neurology, Memory and Aging Center, University of California, San Francisco, CA, USA
| | - John Pluta
- Division of Translational Medicine and Genomics, University of Pennsylvania, Philadelphia, PA, USA
| | - Naftali Raz
- Department of Psychology, Wayne State University, Detroit, MI, USA
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
| | - Karen M. Rodrigue
- Center for Vital Longevity, Behavioral and Brain Science, The University of Texas at Dallas, Dallas, TX, USA
| | | | - Yee Lee Shing
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
- Institute of Psychology, Goethe University Frankfurt, Frankfurt, Germany
| | - Craig E.L. Stark
- Department of Neurobiology and Behavior, Center for Learning and Memory, University of California, Irvine, CA, USA
| | - Trevor A. Steve
- Division of Neurology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Nanthia A. Suthana
- Department of Psychiatry and Biobehavioral Sciences, Department of Neurosurgery, University of California, Los Angeles, CA, USA
| | - Lei Wang
- Department of Psychiatry and Behavioral Sciences and Department Radiology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Markus Werkle-Bergner
- Center for Lifespan Psychology, Max Planck Institute for Human Development, Berlin, Germany
| | - Paul A. Yushkevich
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
| | - Qijing Yu
- Department of Psychology, Wayne State University, Detroit, MI, USA
- Institute of Gerontology, Wayne State University, Detroit, MI, USA
| | - Laura E.M. Wisse
- Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA
- Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
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Shanbhag NM, Evans MD, Mao W, Nana AL, Seeley WW, Adame A, Rissman RA, Masliah E, Mucke L. Early neuronal accumulation of DNA double strand breaks in Alzheimer's disease. Acta Neuropathol Commun 2019; 7:77. [PMID: 31101070 PMCID: PMC6524256 DOI: 10.1186/s40478-019-0723-5] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Accepted: 04/16/2019] [Indexed: 02/06/2023] Open
Abstract
The maintenance of genomic integrity is essential for normal cellular functions. However, it is difficult to maintain over a lifetime in postmitotic cells such as neurons, in which DNA damage increases with age and is exacerbated by multiple neurological disorders, including Alzheimer's disease (AD). Here we used immunohistochemical staining to detect DNA double strand breaks (DSBs), the most severe form of DNA damage, in postmortem brain tissues from patients with mild cognitive impairment (MCI) or AD and from cognitively unimpaired controls. Immunostaining for γH2AX-a post-translational histone modification that is widely used as a marker of DSBs-revealed increased proportions of γH2AX-labeled neurons and astrocytes in the hippocampus and frontal cortex of MCI and AD patients, as compared to age-matched controls. In contrast to the focal pattern associated with DSBs, some neurons and glia in humans and mice showed diffuse pan-nuclear patterns of γH2AX immunoreactivity. In mouse brains and primary neuronal cultures, such pan-nuclear γH2AX labeling could be elicited by increasing neuronal activity. To assess whether pan-nuclear γH2AX represents DSBs, we used a recently developed technology, DNA damage in situ ligation followed by proximity ligation assay, to detect close associations between γH2AX sites and free DSB ends. This assay revealed no evidence of DSBs in neurons or astrocytes with prominent pan-nuclear γH2AX labeling. These findings suggest that focal, but not pan-nuclear, increases in γH2AX immunoreactivity are associated with DSBs in brain tissue and that these distinct patterns of γH2AX formation may have different causes and consequences. We conclude that AD is associated with an accumulation of DSBs in vulnerable neuronal and glial cell populations from early stages onward. Because of the severe adverse effects this type of DNA damage can have on gene expression, chromatin stability and cellular functions, DSBs could be an important causal driver of neurodegeneration and cognitive decline in this disease.
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Affiliation(s)
- Niraj M Shanbhag
- Gladstone Institute of Neurological Disease, San Francisco, CA, 94158, USA
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Mark D Evans
- Gladstone Institute of Neurological Disease, San Francisco, CA, 94158, USA
| | - Wenjie Mao
- Gladstone Institute of Neurological Disease, San Francisco, CA, 94158, USA
| | - Alissa L Nana
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, 94158, USA
- Department of Pathology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - William W Seeley
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, 94158, USA
- Department of Pathology, University of California San Francisco, San Francisco, CA, 94158, USA
| | - Anthony Adame
- Department of Neurosciences, University of California at San Diego, La Jolla, CA, 92093, USA
| | - Robert A Rissman
- Department of Neurosciences, University of California at San Diego, La Jolla, CA, 92093, USA
| | - Eliezer Masliah
- Department of Neurosciences, University of California at San Diego, La Jolla, CA, 92093, USA
- Present address: Division of Neuroscience, National Institute on Aging, Bethesda, MD, 20892, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, San Francisco, CA, 94158, USA.
- Memory and Aging Center, Department of Neurology, University of California San Francisco, San Francisco, CA, 94158, USA.
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Tang X, Ross CA, Johnson H, Paulsen JS, Younes L, Albin RL, Ratnanather JT, Miller MI. Regional subcortical shape analysis in premanifest Huntington's disease. Hum Brain Mapp 2018; 40:1419-1433. [PMID: 30376191 DOI: 10.1002/hbm.24456] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Revised: 10/18/2018] [Accepted: 10/23/2018] [Indexed: 11/11/2022] Open
Abstract
Huntington's disease (HD) involves preferential and progressive degeneration of striatum and other subcortical regions as well as regional cortical atrophy. It is caused by a CAG repeat expansion in the Huntingtin gene, and the longer the expansion the earlier the age of onset. Atrophy begins prior to manifest clinical signs and symptoms, and brain atrophy in premanifest expansion carriers can be studied. We employed a diffeomorphometric pipeline to contrast subcortical structures' morphological properties in a control group with three disease groups representing different phases of premanifest HD (far, intermediate, and near to onset) as defined by the length of the CAG expansion and the participant's age (CAG-Age-Product). A total of 1,428 magnetic resonance image scans from 694 participants from the PREDICT-HD cohort were used. We found significant region-specific atrophies in all subcortical structures studied, with the estimated abnormality onset time varying from structure to structure. Heterogeneous shape abnormalities of caudate nuclei were present in premanifest HD participants estimated furthest from onset and putaminal shape abnormalities were present in participants intermediate to onset. Thalamic, hippocampal, and amygdalar shape abnormalities were present in participants nearest to onset. We assessed whether the estimated progression of subcortical pathology in premanifest HD tracked specific pathways. This is plausible for changes in basal ganglia circuits but probably not for changes in hippocampus and amygdala. The regional shape analyses conducted in this study provide useful insights into the effects of HD pathology in subcortical structures.
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Affiliation(s)
- Xiaoying Tang
- Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, Guangdong, China
| | - Christopher A Ross
- Division of Neurobiology, Departments of Psychiatry, Neurology, Neuroscience and Pharmacology, and Program in Cellular and Molecular Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Hans Johnson
- Departments of Neurology and Psychiatry, The University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Jane S Paulsen
- Departments of Neurology and Psychiatry, The University of Iowa Carver College of Medicine, Iowa City, Iowa
| | - Laurent Younes
- Department of Applied Mathematics and Statistics, Johns Hopkins University, Baltimore, Maryland.,Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland.,Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland
| | - Roger L Albin
- Neurology Service and GRECC, VAAAHS, Ann Arbor, Michigan.,Department of Neurology, University of Michigan Medical School, Ann Arbor, Michigan
| | - J Tilak Ratnanather
- Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland.,Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland
| | - Michael I Miller
- Center for Imaging Science, Johns Hopkins University, Baltimore, Maryland.,Institute for Computational Medicine, Johns Hopkins University, Baltimore, Maryland.,Department of Biomedical Engineering, Johns Hopkins University, Baltimore, Maryland
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Cardoso S, Moreira PI. Diabesity and brain disturbances: A metabolic perspective. Mol Aspects Med 2018; 66:71-79. [PMID: 30321556 DOI: 10.1016/j.mam.2018.10.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Revised: 10/01/2018] [Accepted: 10/10/2018] [Indexed: 12/11/2022]
Abstract
The last decades have been marked by an increased prevalence in non-communicable diseases such as obesity and type 2 diabetes (T2D) as well as by population aging and age-related (brain) diseases. The current notion that the brain and the body are interrelated units is gaining the attention of the scientific and medical community. Growing evidence demonstrates that there is a significant overlap in risk, comorbidity, and pathophysiological mechanisms across obesity, T2D and brain disturbances; settings that seem to be worsened when both obesity and T2D occur simultaneously, the so-called diabesity. Thereupon, there is a great concern to critically appraise and understand the mechanisms by which diabesity can affect brain responses, and may accelerate the decline in brain health. In this framework, metabolic disturbances mediated by altered insulin signaling and mitochondrial function arise among the multifactorial interactions described to occur between obesity, T2D and neurocognitive deficits. In this review we have compiled all the notions and evidence describing how diabesity negatively influences brain function putting the emphasis on insulin signaling pathway disturbances and mitochondrial anomalies. We also debate lifestyle interventions as amenable strategies to lessen metabolic anomalies and, consequently, diabesity-associated brain alterations.
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Affiliation(s)
- Susana Cardoso
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal.
| | - Paula I Moreira
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504, Coimbra, Portugal; Institute of Physiology - Faculty of Medicine - University of Coimbra, 3000-548, Coimbra, Portugal.
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Mitochondria-Targeted Molecules as Potential Drugs to Treat Patients With Alzheimer's Disease. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2017; 146:173-201. [PMID: 28253985 DOI: 10.1016/bs.pmbts.2016.12.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is the most common multifactorial mental illness affecting the elderly population in the world. Its prevalence increases as person ages. There is no known drug or agent that can delay or prevent the AD and its progression. Extensive research has revealed that multiple cellular pathways involved, including amyloid beta production, mitochondrial structural and functional changes, hyperphosphorylation of Tau and NFT formation, inflammatory responses, and neuronal loss in AD pathogenesis. Amyloid beta-induced synaptic damage, mitochondrial abnormalities, and phosphorylated Tau are major areas of present research investigations. Synaptic pathology and mitochondrial oxidative damage are early events in disease process. In this chapter, a systematic literature survey has been conducted and presented a summary of antioxidants used in (1) AD mouse models, (2) elderly populations, and (3) randomized clinical trials in AD patients. This chapter highlights the recent progress in developing and testing mitochondria-targeted molecules using AD cell cultures and AD mouse models. This chapter also discusses recent research on AD pathogenesis and therapeutics, focusing on mitochondria-targeted molecules as potential therapeutic targets to delay or prevent AD progression.
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Abstract
The episodic long-term memory system supports remembering of events. It is considered to be the most age-sensitive system, with an average onset of decline around 60 years of age. However, there is marked interindividual variability, such that some individuals show faster than average change and others show no or very little change. This variability may be related to the risk of developing dementia, with elevated risk for individuals with accelerated episodic memory decline. Brain imaging with functional magnetic resonance imaging (MRI) of blood oxygen level-dependent (BOLD) signalling or positron emission tomography (PET) has been used to reveal the brain bases of declining episodic memory in ageing. Several studies have demonstrated a link between age-related episodic memory decline and the hippocampus during active mnemonic processing, which is further supported by studies of hippocampal functional connectivity in the resting state. The hippocampus interacts with anterior and posterior neocortical regions to support episodic memory, and alterations in hippocampus-neocortex connectivity have been shown to contribute to impaired episodic memory. Multimodal MRI studies and more recently hybrid MRI/PET studies allow consideration of various factors that can influence the association between the hippocampal BOLD signal and memory performance. These include neurovascular factors, grey and white matter structural alterations, dopaminergic neurotransmission, amyloid-Β and glucose metabolism. Knowledge about the brain bases of episodic memory decline can guide interventions to strengthen memory in older adults, particularly in those with an elevated risk of developing dementia, with promising results for combinations of cognitive and physical stimulation.
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Affiliation(s)
- L Nyberg
- Departments of Radiation Sciences and Integrative Medical Biology, Umeå University and Umeå Center for Functional Brain Imaging (UFBI), Umeå University, Umeå, Sweden
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10
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Morzelle MC, Salgado JM, Telles M, Mourelle D, Bachiega P, Buck HS, Viel TA. Neuroprotective Effects of Pomegranate Peel Extract after Chronic Infusion with Amyloid-β Peptide in Mice. PLoS One 2016; 11:e0166123. [PMID: 27829013 PMCID: PMC5102433 DOI: 10.1371/journal.pone.0166123] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 10/24/2016] [Indexed: 01/01/2023] Open
Abstract
Alzheimer’s disease is a chronic and degenerative condition that had no treatment until recently. The current therapeutic strategies reduce progression of the disease but are expensive and commonly cause side effects that are uncomfortable for treated patients. Functional foods to prevent and/or treat many conditions, including neurodegenerative diseases, represent a promising field of study currently gaining attention. To this end, here we demonstrate the effects of pomegranate (Punica granatum) peel extract (PPE) regarding spatial memory, biomarkers of neuroplasticity, oxidative stress and inflammation in a mouse model of neurodegeneration. Male C57Bl/6 mice were chronically infused for 35 days with amyloid-β peptide 1–42 (Aβ) or vehicle (control) using mini-osmotic pumps. Another group, also infused with Aβ, was treated with PPE (p.o.– βA+PPE, 800 mg/kg/day). Spatial memory was evaluated in the Barnes maze. Animals treated with PPE and in the control group exhibited a reduction in failure to find the escape box, a finding that was not observed in the Aβ group. The consumption of PPE reduced amyloid plaque density, increased the expression of neurotrophin BDNF and reduced the activity of acetylcholinesterase enzyme. A reduction in lipid peroxidation and in the concentration of the pro-inflammatory cytokine TNF-α was also observed in the PPE group. No hepatic lesions were observed in animals treated with PPE. In conclusion, administration of pomegranate peel extract has neuroprotective effects involving multiple mechanisms to prevent establishment and progression of the neurodegenerative process induced by infusion with amyloid-β peptide in mice.
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Affiliation(s)
- Maressa Caldeira Morzelle
- Department of Agri-food Industry, Food and Nutrition, ‘Luiz de Queiroz’ College of Agriculture, University of São Paulo, Pádua Dias Avenue, P.O. Box. 9, 13418–900, Piracicaba, SP, Brazil
| | - Jocelem Mastrodi Salgado
- Department of Agri-food Industry, Food and Nutrition, ‘Luiz de Queiroz’ College of Agriculture, University of São Paulo, Pádua Dias Avenue, P.O. Box. 9, 13418–900, Piracicaba, SP, Brazil
| | - Milena Telles
- Graduation Course on Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Avenida Professor Lineu Prestes, 1524, 05508–900, São Paulo, Brazil
| | - Danilo Mourelle
- Graduation Course on Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Avenida Professor Lineu Prestes, 1524, 05508–900, São Paulo, Brazil
| | - Patricia Bachiega
- Department of Agri-food Industry, Food and Nutrition, ‘Luiz de Queiroz’ College of Agriculture, University of São Paulo, Pádua Dias Avenue, P.O. Box. 9, 13418–900, Piracicaba, SP, Brazil
| | - Hudson Sousa Buck
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 111° andar, São Paulo, SP 01221–020, Brazil
| | - Tania Araujo Viel
- Graduation Course on Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Avenida Professor Lineu Prestes, 1524, 05508–900, São Paulo, Brazil
- School of Arts, Sciences and Humanities, Universidade de São Paulo, Av. Arlindo Bettio, 1000, São Paulo, SP 03828–080, Brazil
- * E-mail:
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11
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Xiao Y, Zitella LM, Duchin Y, Teplitzky BA, Kastl D, Adriany G, Yacoub E, Harel N, Johnson MD. Multimodal 7T Imaging of Thalamic Nuclei for Preclinical Deep Brain Stimulation Applications. Front Neurosci 2016; 10:264. [PMID: 27375422 PMCID: PMC4901062 DOI: 10.3389/fnins.2016.00264] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 05/25/2016] [Indexed: 01/14/2023] Open
Abstract
Precise neurosurgical targeting of electrode arrays within the brain is essential to the successful treatment of a range of brain disorders with deep brain stimulation (DBS) therapy. Here, we describe a set of computational tools to generate in vivo, subject-specific atlases of individual thalamic nuclei thus improving the ability to visualize thalamic targets for preclinical DBS applications on a subject-specific basis. A sequential nonlinear atlas warping technique and a Bayesian estimation technique for probabilistic crossing fiber tractography were applied to high field (7T) susceptibility-weighted and diffusion-weighted imaging, respectively, in seven rhesus macaques. Image contrast, including contrast within thalamus from the susceptibility-weighted images, informed the atlas warping process and guided the seed point placement for fiber tractography. The susceptibility-weighted imaging resulted in relative hyperintensity of the intralaminar nuclei and relative hypointensity in the medial dorsal nucleus, pulvinar, and the medial/ventral border of the ventral posterior nuclei, providing context to demarcate borders of the ventral nuclei of thalamus, which are often targeted for DBS applications. Additionally, ascending fiber tractography of the medial lemniscus, superior cerebellar peduncle, and pallidofugal pathways into thalamus provided structural demarcation of the ventral nuclei of thalamus. The thalamic substructure boundaries were validated through in vivo electrophysiological recordings and post-mortem blockface tissue sectioning. Together, these imaging tools for visualizing and segmenting thalamus have the potential to improve the neurosurgical targeting of DBS implants and enhance the selection of stimulation settings through more accurate computational models of DBS.
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Affiliation(s)
- YiZi Xiao
- Department of Biomedical Engineering, University of Minnesota Minneapolis, MN, USA
| | - Laura M Zitella
- Department of Biomedical Engineering, University of Minnesota Minneapolis, MN, USA
| | - Yuval Duchin
- Center for Magnetic Resonance Research, University of Minnesota Minneapolis, MN, USA
| | - Benjamin A Teplitzky
- Department of Biomedical Engineering, University of Minnesota Minneapolis, MN, USA
| | - Daniel Kastl
- Department of Biomedical Engineering, University of Minnesota Minneapolis, MN, USA
| | - Gregor Adriany
- Center for Magnetic Resonance Research, University of Minnesota Minneapolis, MN, USA
| | - Essa Yacoub
- Center for Magnetic Resonance Research, University of Minnesota Minneapolis, MN, USA
| | - Noam Harel
- Center for Magnetic Resonance Research, University of Minnesota Minneapolis, MN, USA
| | - Matthew D Johnson
- Department of Biomedical Engineering, University of MinnesotaMinneapolis, MN, USA; Institute for Translational Neuroscience, University of MinnesotaMinneapolis, MN, USA
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12
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Dotson VM, Szymkowicz SM, Sozda CN, Kirton JW, Green ML, O'Shea A, McLaren ME, Anton SD, Manini TM, Woods AJ. Age Differences in Prefrontal Surface Area and Thickness in Middle Aged to Older Adults. Front Aging Neurosci 2016; 7:250. [PMID: 26834623 PMCID: PMC4717301 DOI: 10.3389/fnagi.2015.00250] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Accepted: 12/21/2015] [Indexed: 02/02/2023] Open
Abstract
Age is associated with reductions in surface area and cortical thickness, particularly in prefrontal regions. There is also evidence of greater thickness in some regions at older ages. Non-linear age effects in some studies suggest that age may continue to impact brain structure in later decades of life, but relatively few studies have examined the impact of age on brain structure within middle-aged to older adults. We investigated age differences in prefrontal surface area and cortical thickness in healthy adults between the ages of 51 and 81 years. Participants received a structural 3-Tesla magnetic resonance imaging scan. Based on a priori hypotheses, primary analyses focused on surface area and cortical thickness in the dorsolateral prefrontal cortex, anterior cingulate cortex, and orbitofrontal cortex. We also performed exploratory vertex-wise analyses of surface area and cortical thickness across the entire cortex. We found that older age was associated with smaller surface area in the dorsolateral prefrontal and orbitofrontal cortices but greater cortical thickness in the dorsolateral prefrontal and anterior cingulate cortices. Vertex-wise analyses revealed smaller surface area in primarily frontal regions at older ages, but no age effects were found for cortical thickness. Results suggest age is associated with reduced surface area but greater cortical thickness in prefrontal regions during later decades of life, and highlight the differential effects age has on regional surface area and cortical thickness.
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Affiliation(s)
- Vonetta M Dotson
- Department of Clinical and Health Psychology, University of FloridaGainesville, FL, USA; Department of Neuroscience, University of FloridaGainesville, FL, USA
| | - Sarah M Szymkowicz
- Department of Clinical and Health Psychology, University of Florida Gainesville, FL, USA
| | - Christopher N Sozda
- Department of Clinical and Health Psychology, University of Florida Gainesville, FL, USA
| | - Joshua W Kirton
- Department of Clinical and Health Psychology, University of Florida Gainesville, FL, USA
| | - Mackenzie L Green
- Department of Clinical and Health Psychology, University of Florida Gainesville, FL, USA
| | - Andrew O'Shea
- Department of Aging & Geriatric Research, University of FloridaGainesville, FL, USA; Center for Cognitive Aging and Memory, Institute on Aging, University of FloridaGainesville, FL, USA
| | - Molly E McLaren
- Department of Clinical and Health Psychology, University of Florida Gainesville, FL, USA
| | - Stephen D Anton
- Department of Aging & Geriatric Research, University of Florida Gainesville, FL, USA
| | - Todd M Manini
- Department of Aging & Geriatric Research, University of Florida Gainesville, FL, USA
| | - Adam J Woods
- Department of Neuroscience, University of FloridaGainesville, FL, USA; Department of Aging & Geriatric Research, University of FloridaGainesville, FL, USA; Center for Cognitive Aging and Memory, Institute on Aging, University of FloridaGainesville, FL, USA
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13
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Augustinack JC, van der Kouwe AJW. Postmortem imaging and neuropathologic correlations. HANDBOOK OF CLINICAL NEUROLOGY 2016; 136:1321-39. [PMID: 27430472 DOI: 10.1016/b978-0-444-53486-6.00069-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Postmortem imaging refers to scanning autopsy specimens using magnetic resonance imaging (MRI) or optical imaging. This chapter summarizes postmortem imaging and its usefulness in brain mapping. Standard in vivo MRI has limited resolution due to time constraints and does not deliver cortical boundaries (e.g., Brodmann areas). Postmortem imaging offers a means to obtain ultra-high-resolution images with appropriate contrast for delineating cortical regions. Postmortem imaging provides the ability to validate MRI properties against histologic stained sections. This approach has enabled probabilistic mapping that is based on ex vivo MRI contrast, validated to histology, and subsequently mapped on to an in vivo model. This chapter emphasizes structural imaging, which can be validated with histologic assessment. Postmortem imaging has been applied to neuropathologic studies as well. This chapter includes many ex vivo studies, but focuses on studies of the medial temporal lobe, often involved in neurologic disease. New research using optical imaging is also highlighted.
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Affiliation(s)
- Jean C Augustinack
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA.
| | - André J W van der Kouwe
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Charlestown, MA, USA
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14
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Nunes MA, Schöwe NM, Monteiro-Silva KC, Baraldi-Tornisielo T, Souza SIG, Balthazar J, Albuquerque MS, Caetano AL, Viel TA, Buck HS. Chronic Microdose Lithium Treatment Prevented Memory Loss and Neurohistopathological Changes in a Transgenic Mouse Model of Alzheimer's Disease. PLoS One 2015; 10:e0142267. [PMID: 26605788 PMCID: PMC4659557 DOI: 10.1371/journal.pone.0142267] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2015] [Accepted: 10/20/2015] [Indexed: 12/28/2022] Open
Abstract
The use of lithium is well established in bipolar disorders and the benefits are being demonstrated in neurodegenerative disorders. Recently, our group showed that treatment with microdose lithium stabilized the cognitive deficits observed in Alzheimer's disease (AD) patients. In order to verify the lithium microdose potential in preventing the disease development, the aim of this work was to verify the effects of chronic treatment with microdose lithium given before and after the appearance of symptoms in a mouse model of a disease similar to AD. Transgenic mice (Cg-Tg(PDGFB-APPSwInd)20Lms/2J) and their non-transgenic litter mate genetic controls were treated with lithium carbonate (0.25mg/Kg/day in drinking water) for 16 or 8 months starting at two and ten months of age, respectively [corrected]. Similar groups were treated with water. At the end of treatments, both lithium treated transgenic groups and non-transgenic mice showed no memory disruption, different from what was observed in the water treated transgenic group. Transgenic mice treated with lithium since two months of age showed decreased number of senile plaques, no neuronal loss in cortex and hippocampus and increased BDNF density in cortex, when compared to non-treated transgenic mice. It is suitable to conclude that these data support the use of microdose lithium in the prevention and treatment of Alzheimer's disease, once the neurohistopathological characteristics of the disease were modified and the memory of transgenic animals was maintained.
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Affiliation(s)
- Marielza Andrade Nunes
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 11° andar, São Paulo, SP 01221–020, Brazil
- Research Group on Neuropharmacology of Aging—ReGNA, Sao Paulo, Brazil
| | - Natalia Mendes Schöwe
- Graduation Course on Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Avenida Professor Lineu Prestes, 1524, 05508–900 São Paulo, Brazil
- Research Group on Neuropharmacology of Aging—ReGNA, Sao Paulo, Brazil
| | - Karla Cristina Monteiro-Silva
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 11° andar, São Paulo, SP 01221–020, Brazil
| | - Ticiana Baraldi-Tornisielo
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 11° andar, São Paulo, SP 01221–020, Brazil
- Research Group on Neuropharmacology of Aging—ReGNA, Sao Paulo, Brazil
| | - Suzzanna Ingryd Gonçalves Souza
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 11° andar, São Paulo, SP 01221–020, Brazil
| | - Janaina Balthazar
- Graduation Course on Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Avenida Professor Lineu Prestes, 1524, 05508–900 São Paulo, Brazil
| | - Marilia Silva Albuquerque
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 11° andar, São Paulo, SP 01221–020, Brazil
- Research Group on Neuropharmacology of Aging—ReGNA, Sao Paulo, Brazil
| | - Ariadiny Lima Caetano
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 11° andar, São Paulo, SP 01221–020, Brazil
- Research Group on Neuropharmacology of Aging—ReGNA, Sao Paulo, Brazil
| | - Tania Araujo Viel
- Graduation Course on Pharmacology, Institute of Biomedical Sciences, Universidade de São Paulo, Avenida Professor Lineu Prestes, 1524, 05508–900 São Paulo, Brazil
- School of Arts, Sciences and Humanities, Universidade de São Paulo, Av. Arlindo Bettio, 1000, São Paulo, SP 03828–080, Brazil
- Research Group on Neuropharmacology of Aging—ReGNA, Sao Paulo, Brazil
| | - Hudson Sousa Buck
- Department of Physiological Sciences, Santa Casa de São Paulo School of Medical Sciences, R. Dr. Cesario Motta Junior, 61, 11° andar, São Paulo, SP 01221–020, Brazil
- Research Group on Neuropharmacology of Aging—ReGNA, Sao Paulo, Brazil
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15
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Tiwari V, Solanki V, Tiwari M. In-vivoandin-vitrotechniques used to investigate Alzheimer's disease. FRONTIERS IN LIFE SCIENCE 2015. [DOI: 10.1080/21553769.2015.1044129] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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16
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Yushkevich PA, Amaral RSC, Augustinack JC, Bender AR, Bernstein JD, Boccardi M, Bocchetta M, Burggren AC, Carr VA, Chakravarty MM, Chételat G, Daugherty AM, Davachi L, Ding SL, Ekstrom A, Geerlings MI, Hassan A, Huang Y, Iglesias JE, La Joie R, Kerchner GA, LaRocque KF, Libby LA, Malykhin N, Mueller SG, Olsen RK, Palombo DJ, Parekh MB, Pluta JB, Preston AR, Pruessner JC, Ranganath C, Raz N, Schlichting ML, Schoemaker D, Singh S, Stark CEL, Suthana N, Tompary A, Turowski MM, Van Leemput K, Wagner AD, Wang L, Winterburn JL, Wisse LEM, Yassa MA, Zeineh MM. Quantitative comparison of 21 protocols for labeling hippocampal subfields and parahippocampal subregions in in vivo MRI: towards a harmonized segmentation protocol. Neuroimage 2015; 111:526-41. [PMID: 25596463 PMCID: PMC4387011 DOI: 10.1016/j.neuroimage.2015.01.004] [Citation(s) in RCA: 234] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2014] [Revised: 11/25/2014] [Accepted: 01/01/2015] [Indexed: 11/16/2022] Open
Abstract
OBJECTIVE An increasing number of human in vivo magnetic resonance imaging (MRI) studies have focused on examining the structure and function of the subfields of the hippocampal formation (the dentate gyrus, CA fields 1-3, and the subiculum) and subregions of the parahippocampal gyrus (entorhinal, perirhinal, and parahippocampal cortices). The ability to interpret the results of such studies and to relate them to each other would be improved if a common standard existed for labeling hippocampal subfields and parahippocampal subregions. Currently, research groups label different subsets of structures and use different rules, landmarks, and cues to define their anatomical extents. This paper characterizes, both qualitatively and quantitatively, the variability in the existing manual segmentation protocols for labeling hippocampal and parahippocampal substructures in MRI, with the goal of guiding subsequent work on developing a harmonized substructure segmentation protocol. METHOD MRI scans of a single healthy adult human subject were acquired both at 3 T and 7 T. Representatives from 21 research groups applied their respective manual segmentation protocols to the MRI modalities of their choice. The resulting set of 21 segmentations was analyzed in a common anatomical space to quantify similarity and identify areas of agreement. RESULTS The differences between the 21 protocols include the region within which segmentation is performed, the set of anatomical labels used, and the extents of specific anatomical labels. The greatest overall disagreement among the protocols is at the CA1/subiculum boundary, and disagreement across all structures is greatest in the anterior portion of the hippocampal formation relative to the body and tail. CONCLUSIONS The combined examination of the 21 protocols in the same dataset suggests possible strategies towards developing a harmonized subfield segmentation protocol and facilitates comparison between published studies.
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Affiliation(s)
- Paul A Yushkevich
- Penn Image Computing and Science Laboratory, Department of Radiology, University of Pennsylvania, USA.
| | - Robert S C Amaral
- Cerebral Imaging Centre, Douglas Mental Health University Institute, McGill University, Canada
| | - Jean C Augustinack
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, USA
| | | | - Jeffrey D Bernstein
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, USA; Stanford Center for Memory Disorders, USA
| | - Marina Boccardi
- LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine), IRCCS Centro S. Giovanni di Dio Fatebenefratelli, Italy
| | - Martina Bocchetta
- LENITEM (Laboratory of Epidemiology, Neuroimaging and Telemedicine), IRCCS Centro S. Giovanni di Dio Fatebenefratelli, Italy; Department of Molecular and Translational Medicine, University of Brescia, Brescia, Italy
| | - Alison C Burggren
- Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, USA
| | | | - M Mallar Chakravarty
- Cerebral Imaging Centre, Douglas Mental Health University Institute, McGill University, Canada; Department of Psychiatry, Department of Biomedical Engineering, McGill University, Canada
| | - Gaël Chételat
- INSERM U1077, Universitè de Caen Basse-Normandie, UMR-S1077, Ecole Pratique des Hautes Etudes, CHU de Caen, U1077, Caen, France
| | - Ana M Daugherty
- Institute of Gerontology, Wayne State University, USA; Psychology Department, Wayne State University, USA
| | - Lila Davachi
- Department of Psychology, New York University, USA; Center for Neural Science, New York University, USA
| | | | - Arne Ekstrom
- Center for Neuroscience, University of California, Davis, USA; Department of Psychology, University of California, Davis, USA
| | - Mirjam I Geerlings
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Netherlands
| | - Abdul Hassan
- Center for Neuroscience, University of California, Davis, USA
| | - Yushan Huang
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada
| | - J Eugenio Iglesias
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, USA; Basque Center on Cognition, Brain and Language (BCBL), Donostia-San Sebastian, Spain
| | - Renaud La Joie
- INSERM U1077, Universitè de Caen Basse-Normandie, UMR-S1077, Ecole Pratique des Hautes Etudes, CHU de Caen, U1077, Caen, France
| | - Geoffrey A Kerchner
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, USA; Stanford Center for Memory Disorders, USA
| | | | - Laura A Libby
- Center for Neuroscience, University of California, Davis, USA
| | - Nikolai Malykhin
- Department of Biomedical Engineering, University of Alberta, Edmonton, Alberta, Canada; Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
| | - Susanne G Mueller
- Department of Radiology, University of California, San Francisco, USA; Center for Imaging of Neurodegenerative Diseases, San Francisco VA Medical Center, USA
| | | | | | | | - John B Pluta
- Penn Image Computing and Science Laboratory, Department of Radiology, University of Pennsylvania, USA; Department of Biostatistics, University of Pennsylvania, USA
| | - Alison R Preston
- Department of Psychology, The University of Texas at Austin, USA; Center for Learning and Memory, The University of Texas at Austin, USA; Department of Neuroscience, The University of Texas at Austin, USA
| | - Jens C Pruessner
- McGill Centre for Studies in Aging, Faculty of Medicine, McGill University, Canada; Department of Psychology, McGill University, Canada
| | - Charan Ranganath
- Department of Psychology, University of California, Davis, USA; Center for Neuroscience, University of California, Davis, USA
| | - Naftali Raz
- Institute of Gerontology, Wayne State University, USA; Psychology Department, Wayne State University, USA
| | - Margaret L Schlichting
- Department of Psychology, The University of Texas at Austin, USA; Center for Learning and Memory, The University of Texas at Austin, USA
| | - Dorothee Schoemaker
- McGill Centre for Studies in Aging, Faculty of Medicine, McGill University, Canada; Department of Psychology, McGill University, Canada
| | - Sachi Singh
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, USA
| | - Craig E L Stark
- Department of Neurobiology and Behavior, University of California, Irvine, USA
| | - Nanthia Suthana
- Department of Neurosurgery, University of California, Los Angeles, USA
| | | | - Marta M Turowski
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, USA
| | - Koen Van Leemput
- A.A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, USA; Department of Applied Mathematics and Computer Science, Technical University of Denmark, Denmark
| | - Anthony D Wagner
- Department of Psychology, Stanford University, USA; Neurosciences Program, Stanford University, USA
| | - Lei Wang
- Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, USA; Department of Radiology, Northwestern University Feinberg School of Medicine, USA
| | - Julie L Winterburn
- Cerebral Imaging Centre, Douglas Mental Health University Institute, McGill University, Canada
| | - Laura E M Wisse
- Julius Center for Health Sciences and Primary Care, University Medical Center Utrecht, Netherlands
| | - Michael A Yassa
- Department of Neurobiology and Behavior, University of California, Irvine, USA
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Schoene‐Bake J, Keller SS, Niehusmann P, Volmering E, Elger C, Deppe M, Weber B. In vivo mapping of hippocampal subfields in mesial temporal lobe epilepsy: relation to histopathology. Hum Brain Mapp 2014; 35:4718-28. [PMID: 24638919 PMCID: PMC6869541 DOI: 10.1002/hbm.22506] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2013] [Revised: 12/10/2013] [Accepted: 02/25/2014] [Indexed: 11/06/2022] Open
Abstract
A particularly popular automated magnetic resonance imaging (MRI) hippocampal subfield mapping technique is the one described by Van Leemput et al. (2009: Hippocampus 19:549-557) that is currently distributed with FreeSurfer software. This method assesses the probabilistic locations of subfields based on a priori knowledge of subfield topology determined from high-field MRI. Many studies have applied this technique to conventionally acquired T1-weighted MRI data. In the present study, we investigated the relationship between this technique applied to conventional T1-weighted MRI data acquired at 3 T and postsurgical hippocampal histology in patients with medically intractable mesial temporal lobe epilepsy (mTLE) and hippocampal sclerosis (HS). Patients with mTLE (n = 82) exhibited significant volume loss of ipsilateral CA1, CA2-3, CA4-dentate gyrus (DG), subiculum, and fimbria relative to controls (n = 81). Histopathological analysis indicated that the most significant neuronal loss was observed in CA1, then CA4 and CA3, and more subtle neuronal loss in CA2, consistent with classical HS. Neuronal density of CA1 significantly correlated with MRI-determined volume of CA1, and increasingly so with CA2-3 and CA4-DG. Patients with increased HS based on histopathology had greater volume loss of the ipsilateral hippocampal regions on MRI. We conclude by suggesting that whilst time efficient and fully reproducible when applied to conventional single acquisition sequences, the use of the automated subfield technique described here may necessitate the application to multiacquisition high-resolution MR sequences for accurate delineation of hippocampal subfields.
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Affiliation(s)
- Jan‐Christoph Schoene‐Bake
- Department of EpileptologyUniversity of BonnBonnGermany
- Department of NeuroCognition/ImagingLife & Brain Research CenterBonnGermany
| | - Simon S. Keller
- Department of Molecular and Clinical PharmacologyInstitute of Translational Medicine, University of LiverpoolLiverpoolUnited Kingdom
- Department of Clinical NeuroscienceInstitute of Psychiatry, King's College LondonLondonUnited Kingdom
| | | | | | | | - Michael Deppe
- Department of NeurologyUniversity of MünsterMünsterGermany
| | - Bernd Weber
- Department of EpileptologyUniversity of BonnBonnGermany
- Department of NeuroCognition/ImagingLife & Brain Research CenterBonnGermany
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Tang X, Holland D, Dale AM, Younes L, Miller MI. Shape abnormalities of subcortical and ventricular structures in mild cognitive impairment and Alzheimer's disease: detecting, quantifying, and predicting. Hum Brain Mapp 2014; 35:3701-25. [PMID: 24443091 DOI: 10.1002/hbm.22431] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 09/04/2013] [Accepted: 11/06/2013] [Indexed: 01/18/2023] Open
Abstract
This article assesses the feasibility of using shape information to detect and quantify the subcortical and ventricular structural changes in mild cognitive impairment (MCI) and Alzheimer's disease (AD) patients. We first demonstrate structural shape abnormalities in MCI and AD as compared with healthy controls (HC). Exploring the development to AD, we then divide the MCI participants into two subgroups based on longitudinal clinical information: (1) MCI patients who remained stable; (2) MCI patients who converted to AD over time. We focus on seven structures (amygdala, hippocampus, thalamus, caudate, putamen, globus pallidus, and lateral ventricles) in 754 MR scans (210 HC, 369 MCI of which 151 converted to AD over time, and 175 AD). The hippocampus and amygdala were further subsegmented based on high field 0.8 mm isotropic 7.0T scans for finer exploration. For MCI and AD, prominent ventricular expansions were detected and we found that these patients had strongest hippocampal atrophy occurring at CA1 and strongest amygdala atrophy at the basolateral complex. Mild atrophy in basal ganglia structures was also detected in MCI and AD. Stronger atrophy in the amygdala and hippocampus, and greater expansion in ventricles was observed in MCI converters, relative to those MCI who remained stable. Furthermore, we performed principal component analysis on a linear shape space of each structure. A subsequent linear discriminant analysis on the principal component values of hippocampus, amygdala, and ventricle leads to correct classification of 88% HC subjects and 86% AD subjects.
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Affiliation(s)
- Xiaoying Tang
- Center for Imaging Science, Johns Hopkins University, Baltimore, MD, USA; Department of Electrical and Computer Engineering, Johns Hopkins University, Baltimore, MD, USA
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Chiu MJ, Yang SY, Horng HE, Yang CC, Chen TF, Chieh JJ, Chen HH, Chen TC, Ho CS, Chang SF, Liu HC, Hong CY, Yang HC. Combined plasma biomarkers for diagnosing mild cognition impairment and Alzheimer's disease. ACS Chem Neurosci 2013; 4:1530-6. [PMID: 24090201 DOI: 10.1021/cn400129p] [Citation(s) in RCA: 102] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
A highly sensitive immunoassay, the immunomagnetic reduction, is used to measure several biomarkers for plasma that is related to Alzheimer's disease (AD). These biomarkers include Aβ-40, Aβ-42, and tau proteins. The samples are composed of four groups: healthy controls (n=66), mild cognitive impairment (MCI, n=22), very mild dementia (n=23), and mild-to-serve dementia, all due to AD (n=22). It is found that the concentrations of both Aβ-42 and tau protein for the healthy controls are significantly lower than those of all of the other groups. The sensitivity and the specificity of plasma Aβ-42 and tau protein in differentiating MCI from AD are all around 0.9 (0.88-0.97). However, neither plasma Aβ-42 nor tau-protein concentration is an adequate parameter to distinguish MCI from AD. A parameter is proposed, which is the product of plasma Aβ-42 and tau-protein levels, to differentiate MCI from AD. The sensitivity and specificity are found to be 0.80 and 0.82, respectively. It is concluded that the use of combined plasma biomarkers not only allows the differentiation of the healthy controls and patients with AD in both the prodromal phase and the dementia phase, but it also allows AD in the prodromal phase to be distinguished from that in the dementia phase.
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Affiliation(s)
- Ming-Jang Chiu
- Department
of Neurology, National Taiwan University
Hospital, College of Medicine, National Taiwan University, Taipei 100, Taiwan
- Graduate
Institute of Brain and Mind Sciences, College
of Medicine, National Taiwan University, Taipei 100, Taiwan
- Department
of Psychology, National Taiwan University, Taipei 100, Taiwan
- Graduate
Institute of Biomedical Engineering and Bioinformatics, National Taiwan University, Taipei 116, Taiwan
| | - Shieh-Yueh Yang
- Institute
of Electro-optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan
- MagQu Co., Ltd., Xindian District, New Taipei
City 231, Taiwan
| | - Herng-Er Horng
- Institute
of Electro-optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan
| | - Che-Chuan Yang
- MagQu Co., Ltd., Xindian District, New Taipei
City 231, Taiwan
| | - Ta-Fu Chen
- Department
of Neurology, National Taiwan University
Hospital, College of Medicine, National Taiwan University, Taipei 100, Taiwan
| | - Jen-Je Chieh
- Institute
of Electro-optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan
| | - Hsin-Hsien Chen
- Institute
of Electro-optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan
| | - Ting-Chi Chen
- MagQu Co., Ltd., Xindian District, New Taipei
City 231, Taiwan
| | - Chia-Shin Ho
- MagQu Co., Ltd., Xindian District, New Taipei
City 231, Taiwan
| | - Shuo-Fen Chang
- MagQu Co., Ltd., Xindian District, New Taipei
City 231, Taiwan
| | - Hao Chun Liu
- Institute
of Electro-optical Science and Technology, National Taiwan Normal University, Taipei 116, Taiwan
| | - Chin-Yih Hong
- Graduate
Institute of Bio-medical Engineering, National Chung Hsing University, Taichung 402, Taiwan
| | - Hong-Chang Yang
- Department
of Electro-optical Engineering, Kun Shan University, Yongkang District, Tainan City 710, Taiwan
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20
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R6/2 Huntington's disease mice develop early and progressive abnormal brain metabolism and seizures. J Neurosci 2012; 32:6456-67. [PMID: 22573668 DOI: 10.1523/jneurosci.0388-12.2012] [Citation(s) in RCA: 63] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
A hallmark feature of Huntington's disease pathology is the atrophy of brain regions including, but not limited to, the striatum. Though MRI studies have identified structural CNS changes in several Huntington's disease (HD) mouse models, the functional consequences of HD pathology during the progression of the disease have yet to be investigated using in vivo functional MRI (fMRI). To address this issue, we first established the structural and functional MRI phenotype of juvenile HD mouse model R6/2 at early and advanced stages of disease. Significantly higher fMRI signals [relative cerebral blood volumes (rCBVs)] and atrophy were observed in both age groups in specific brain regions. Next, fMRI results were correlated with electrophysiological analysis, which showed abnormal increases in neuronal activity in affected brain regions, thus identifying a mechanism accounting for the abnormal fMRI findings. [(14)C] 2-deoxyglucose maps to investigate patterns of glucose utilization were also generated. An interesting mismatch between increases in rCBV and decreases in glucose uptake was observed. Finally, we evaluated the sensitivity of this mouse line to audiogenic seizures early in the disease course. We found that R6/2 mice had an increased susceptibility to develop seizures. Together, these findings identified seizure activity in R6/2 mice and show that neuroimaging measures sensitive to oxygen metabolism can be used as in vivo biomarkers, preceding the onset of an overt behavioral phenotype. Since fMRI-rCBV can also be obtained in patients, we propose that it may serve as a translational tool to evaluate therapeutic responses in humans and HD mouse models.
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Kremen WS, Thompson-Brenner H, Leung YMJ, Grant MD, Franz CE, Eisen SA, Jacobson KC, Boake C, Lyons MJ. Genes, Environment, and Time: The Vietnam Era Twin Study of Aging (VETSA). Twin Res Hum Genet 2012. [DOI: 10.1375/twin.9.6.1009] [Citation(s) in RCA: 109] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
AbstractThe Vietnam Era Twin Study of Aging (VETSA) is a large-scale investigation of cognitive aging from middle to later age. The intended sample of 1440 twin subjects is recruited from the Vietnam Era Twin Registry (VETR), a registry of middle-aged male-male twin pairs who both served in the military during the Vietnam conflict (1965–1975). VETSA employs a multitrait multimethod approach to cognitive assessment to focus on the genetic and environmental contributions to cognitive processes over time, as well as the relative contributions to cognitive aging from health, social, personality, and other contextual factors. The cognitive domains of episodic memory, working memory, abstract reasoning, and inhibitory executive functioning are assessed through neuropsychological testing. In addition, VETSA obtains the participant's score on the Armed Forces Qualification Test, taken at the time of induction into the military around age 20 years, and readministers the test. Two other projects — VETSA Cortisol and VETSA Magnetic Resonance Imaging — are also in progress using subsamples of the VETSA twins. Prior waves of data collection by VETSA investigators using the VETR have provided historical data on physical and mental health, while future waves of VETSA data collection are planned every 5 years. These methods will provide data on multiple pheno-types in the same individuals with regard to genetic and environmental contributions to cognitive functioning over time, personality and interpersonal risk and protective factors, stress and cortisol regulation, and structural brain correlates of aging processes.
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22
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Das SR, Avants BB, Pluta J, Wang H, Suh JW, Weiner MW, Mueller SG, Yushkevich PA. Measuring longitudinal change in the hippocampal formation from in vivo high-resolution T2-weighted MRI. Neuroimage 2012; 60:1266-79. [PMID: 22306801 DOI: 10.1016/j.neuroimage.2012.01.098] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2011] [Revised: 01/12/2012] [Accepted: 01/18/2012] [Indexed: 01/14/2023] Open
Abstract
The hippocampal formation (HF) is a brain structure of great interest because of its central role in learning and memory, and its associated vulnerability to several neurological disorders. In vivo oblique coronal T2-weighted MRI with high in-plane resolution (~0.5 mm × 0.5 mm), thick slices (~2.0 mm), and a field of view tailored to imaging the hippocampal formation (denoted HF-MRI in this paper) has been advanced as a useful imaging modality for detailed hippocampal morphometry. Cross-sectional analysis of volume measurements derived from HF-MRI has shown the modality's promise to yield sensitive imaging-based biomarker for neurological disorders such as Alzheimer's disease. However, the utility of this modality for making measurements of longitudinal change has not yet been demonstrated. In this paper, using an unbiased deformation-based morphometry (DBM) pipeline, we examine the suitability of HF-MRI for estimating longitudinal change by comparing atrophy rates measured in the whole hippocampus from this modality with those measured from more common isotropic (~1 mm³) T1-weighted MRI in the same set of individuals, in a cohort of healthy controls and patients with cognitive impairment. While measurements obtained from HF-MRI were largely consistent with those obtained from T1-MRI, HF-MRI yielded slightly larger group effect of greater atrophy rates in patients than in controls. The estimated minimum sample size required for detecting a 25% change in patients' atrophy rate in the hippocampus compared to the control group with a statistical power β=0.8 was N=269. For T1-MRI, the equivalent sample size was N=325. Using a dataset of test-retest scans, we show that the measurements were free of additive bias. We also demonstrate that these results were not a confound of certain methodological choices made in the DBM pipeline to address the challenges of making longitudinal measurements from HF-MRI, using a region of interest (ROI) around the HF to globally align serial images, followed by slice-by-slice deformable registration to measure local volume change. Additionally, we present a preliminary study of atrophy rate measurements within hippocampal subfields using HF-MRI. Cross-sectional differences in atrophy rates were detected in several subfields.
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Affiliation(s)
- Sandhitsu R Das
- Penn Image Computing and Science Laboratory-PICSL, Department of Radiology, University of Pennsylvania, Philadelphia, PA, USA.
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23
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Small SA. Neurobiological correlates of imaging. NETWORK (BRISTOL, ENGLAND) 2011; 22:162-172. [PMID: 22149677 DOI: 10.3109/0954898x.2011.638695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
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24
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Nearly automatic segmentation of hippocampal subfields in in vivo focal T2-weighted MRI. Neuroimage 2010; 53:1208-24. [PMID: 20600984 DOI: 10.1016/j.neuroimage.2010.06.040] [Citation(s) in RCA: 183] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2010] [Revised: 06/12/2010] [Accepted: 06/16/2010] [Indexed: 11/24/2022] Open
Abstract
We present and evaluate a new method for automatically labeling the subfields of the hippocampal formation in focal 0.4 × 0.5 × 2.0mm(3) resolution T2-weighted magnetic resonance images that can be acquired in the routine clinical setting with under 5 min scan time. The method combines multi-atlas segmentation, similarity-weighted voting, and a novel learning-based bias correction technique to achieve excellent agreement with manual segmentation. Initial partitioning of MRI slices into hippocampal 'head', 'body' and 'tail' slices is the only input required from the user, necessitated by the nature of the underlying segmentation protocol. Dice overlap between manual and automatic segmentation is above 0.87 for the larger subfields, CA1 and dentate gyrus, and is competitive with the best results for whole-hippocampus segmentation in the literature. Intraclass correlation of volume measurements in CA1 and dentate gyrus is above 0.89. Overlap in smaller hippocampal subfields is lower in magnitude (0.54 for CA2, 0.62 for CA3, 0.77 for subiculum and 0.79 for entorhinal cortex) but comparable to overlap between manual segmentations by trained human raters. These results support the feasibility of subfield-specific hippocampal morphometry in clinical studies of memory and neurodegenerative disease.
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25
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Carr VA, Rissman J, Wagner AD. Imaging the human medial temporal lobe with high-resolution fMRI. Neuron 2010; 65:298-308. [PMID: 20159444 DOI: 10.1016/j.neuron.2009.12.022] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/01/2009] [Indexed: 12/17/2022]
Abstract
High-resolution functional MRI (hr-fMRI) affords unique leverage on the functional properties of human medial temporal lobe (MTL) substructures. We review initial hr-fMRI efforts to delineate (1) encoding and retrieval processes within the hippocampal circuit, (2) hippocampal subfield contributions to pattern separation and pattern completion, and (3) the representational capabilities of distinct MTL subregions. Extant data reveal functional heterogeneity within human MTL and highlight the promise of hr-fMRI for bridging human, animal, and computational approaches to understanding MTL function.
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Affiliation(s)
- Valerie A Carr
- Department of Psychology, Stanford University, Stanford, CA 94305, USA.
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26
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Mueller SG, Weiner MW, Thal LJ, Petersen RC, Jack CR, Jagust W, Trojanowski JQ, Toga AW, Beckett L. Ways toward an early diagnosis in Alzheimer's disease: the Alzheimer's Disease Neuroimaging Initiative (ADNI). Alzheimers Dement 2009; 1:55-66. [PMID: 17476317 PMCID: PMC1864941 DOI: 10.1016/j.jalz.2005.06.003] [Citation(s) in RCA: 678] [Impact Index Per Article: 45.2] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
With the increasing life expectancy in developed countries, the incidence of Alzheimer's disease (AD) and thus its socioeconomic impact are growing. Increasing knowledge over the last years about the pathomechanisms involved in AD allow for the development of specific treatment strategies aimed at slowing down or even preventing neuronal death in AD. However, this requires also that (1) AD can be diagnosed with high accuracy, because non-AD dementias would not benefit from an AD-specific treatment; (2) AD can be diagnosed in very early stages when any intervention would be most effective; and (3) treatment efficacy can be reliably and meaningfully monitored. Although there currently is no ideal biomarker that would fulfill all these requirements, there is increasing evidence that a combination of currently existing neuroimaging and cerebrospinal fluid (CSF) and blood biomarkers can provide important complementary information and thus contribute to a more accurate and earlier diagnosis of AD. The Alzheimer's Disease Neuroimaging Initiative (ADNI) is exploring which combinations of these biomarkers are the most powerful for diagnosis of AD and monitoring of treatment effects.
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Affiliation(s)
- Susanne G. Mueller
- Center for Imaging of Neurodegenerative Diseases, Veterans Administration Medical Center, San Francisco, CA, USA
- Department of Radiology, University of California, San Francisco, USA
| | - Michael W. Weiner
- Center for Imaging of Neurodegenerative Diseases, Veterans Administration Medical Center, San Francisco, CA, USA
- Department of Radiology, University of California, San Francisco, USA
- Department of Neurology, Psychiatry and Medicine, University of California, San Francisco, USA
- * Corresponding author. Tel.: 415-221-4810 ext 3642; Fax: 415-668-2864. E-mail address: (M. Weiner)
| | - Leon J. Thal
- Department of Neuroscience, University of California, San Diego, USA
| | - Ronald C. Petersen
- Department of Neurology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - Clifford R. Jack
- Department of Radiology, Mayo Clinic College of Medicine, Rochester, MN, USA
| | - William Jagust
- School of Public Health and Helen Wills Neuroscience Institute, University of California, Berkeley, USA
| | | | - Arthur W. Toga
- Department of Neurology, University of California, Los Angeles, USA
| | - Laurel Beckett
- Department of Public Health Science, University of California, Davis, USA
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27
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Schobel SA, Lewandowski NM, Corcoran CM, Moore H, Brown T, Malaspina D, Small SA. Differential targeting of the CA1 subfield of the hippocampal formation by schizophrenia and related psychotic disorders. ACTA ACUST UNITED AC 2009; 66:938-46. [PMID: 19736350 DOI: 10.1001/archgenpsychiatry.2009.115] [Citation(s) in RCA: 281] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
CONTEXT Because schizophrenia and related disorders have a chronic time course and subtle histopathology, it is difficult to identify which brain regions are differentially targeted. OBJECTIVE To identify brain sites differentially targeted by schizophrenia, we applied a high-resolution variant of functional magnetic resonance imaging to clinically characterized patients and matched healthy controls and to a cohort of prodromal subjects who were prospectively followed up. Additionally, to explore the potential confound of medication use, the fMRI variant was applied to rodents receiving an antipsychotic agent. DESIGN Cross-sectional and prospective cohort designs. SETTING Hospital clinic and magnetic resonance imaging laboratory. PARTICIPANTS Eighteen patients with schizophrenia, 18 controls comparable in age and sex, and 18 prodromal patients followed up prospectively for 2 years. Ten C57-B mice received an antipsychotic agent or vehicle control. MAIN OUTCOME MEASURES Regional cerebral blood volume (CBV), as measured with magnetic resonance imaging, and symptom severity, as measured with clinical rating scales. RESULTS In a first between-group analysis that compared patients with schizophrenia with controls, results revealed abnormal CBV increases in the CA1 subfield and the orbitofrontal cortex and abnormal CBV decreases in the dorsolateral prefrontal cortex. In a second longitudinal analysis, baseline CBV abnormalities in the CA1 subfield differentially predicted clinical progression to psychosis from a prodromal state. In a third correlational analysis, CBV levels in the CA1 subfield differentially correlated with clinical symptoms of psychosis. Finally, additional analyses of the human data set and imaging studies in mice suggested that antipsychotic agents were not confounding the primary findings. CONCLUSIONS Taken as a whole, the results suggest that the CA1 subfield of the hippocampal subregion is differentially targeted by schizophrenia and related psychotic disorders. Interpreted in the context of previous studies, these findings inform underlying mechanisms of illness progression.
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Affiliation(s)
- Scott A Schobel
- Department of Psychiatry, Columbia University, College of Physicians and Surgeons, New York, New York, USA
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28
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Van Leemput K, Bakkour A, Benner T, Wiggins G, Wald LL, Augustinack J, Dickerson BC, Golland P, Fischl B. Automated segmentation of hippocampal subfields from ultra-high resolution in vivo MRI. Hippocampus 2009; 19:549-57. [PMID: 19405131 DOI: 10.1002/hipo.20615] [Citation(s) in RCA: 322] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recent developments in MRI data acquisition technology are starting to yield images that show anatomical features of the hippocampal formation at an unprecedented level of detail, providing the basis for hippocampal subfield measurement. However, a fundamental bottleneck in MRI studies of the hippocampus at the subfield level is that they currently depend on manual segmentation, a laborious process that severely limits the amount of data that can be analyzed. In this article, we present a computational method for segmenting the hippocampal subfields in ultra-high resolution MRI data in a fully automated fashion. Using Bayesian inference, we use a statistical model of image formation around the hippocampal area to obtain automated segmentations. We validate the proposed technique by comparing its segmentations to corresponding manual delineations in ultra-high resolution MRI scans of 10 individuals, and show that automated volume measurements of the larger subfields correlate well with manual volume estimates. Unlike manual segmentations, our automated technique is fully reproducible, and fast enough to enable routine analysis of the hippocampal subfields in large imaging studies.
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Affiliation(s)
- Koen Van Leemput
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA.
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29
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Abstract
There are declines with age in speed of processing, working memory, inhibitory function, and long-term memory, as well as decreases in brain structure size and white matter integrity. In the face of these decreases, functional imaging studies have demonstrated, somewhat surprisingly, reliable increases in prefrontal activation. To account for these joint phenomena, we propose the scaffolding theory of aging and cognition (STAC). STAC provides an integrative view of the aging mind, suggesting that pervasive increased frontal activation with age is a marker of an adaptive brain that engages in compensatory scaffolding in response to the challenges posed by declining neural structures and function. Scaffolding is a normal process present across the lifespan that involves use and development of complementary, alternative neural circuits to achieve a particular cognitive goal. Scaffolding is protective of cognitive function in the aging brain, and available evidence suggests that the ability to use this mechanism is strengthened by cognitive engagement, exercise, and low levels of default network engagement.
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Affiliation(s)
- Denise C Park
- The Center for Brain Health, University of Texas at Dallas, Dallas, Texas 75235, USA.
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30
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Van Leemput K, Bakkour A, Benner T, Wiggins G, Wald LL, Augustinack J, Dickerson BC, Golland P, Fischl B. Model-based segmentation of hippocampal subfields in ultra-high resolution in vivo MRI. ACTA ACUST UNITED AC 2008; 11:235-43. [PMID: 18979753 DOI: 10.1007/978-3-540-85988-8_29] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/15/2023]
Abstract
Recent developments in MR data acquisition technology are starting to yield images that show anatomical features of the hippocampal formation at an unprecedented level of detail, providing the basis for hippocampal subfield measurement. Because of the role of the hippocampus in human memory and its implication in a variety of disorders and conditions, the ability to reliably and efficiently quantify its subfields through in vivo neuroimaging is of great interest to both basic neuroscience and clinical research. In this paper, we propose a fully-automated method for segmenting the hippocampal subfields in ultra-high resolution MRI data. Using a Bayesian approach, we build a computational model of how images around the hippocampal area are generated, and use this model to obtain automated segmentations. We validate the proposed technique by comparing our segmentation results with corresponding manual delineations in ultra-high resolution MRI scans of five individuals.
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Affiliation(s)
- Koen Van Leemput
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, MGH, Harvard Medical School, USA
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31
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Burggren AC, Zeineh MM, Ekstrom AD, Braskie MN, Thompson PM, Small GW, Bookheimer SY. Reduced cortical thickness in hippocampal subregions among cognitively normal apolipoprotein E e4 carriers. Neuroimage 2008; 41:1177-83. [PMID: 18486492 DOI: 10.1016/j.neuroimage.2008.03.039] [Citation(s) in RCA: 168] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2007] [Revised: 03/18/2008] [Accepted: 03/19/2008] [Indexed: 11/25/2022] Open
Abstract
Our objective was to investigate whether asymptomatic carriers of apolipoprotein E epsilon4 [APOE-4] demonstrate pathological differences and atrophy in medial temporal lobe (MTL) subregions. We measured cortical thickness and volume in MTL subregions (hippocampal CA fields 1, 2 and 3; dentate gyrus; entorhinal cortex; subiculum; perirhinal cortex; parahippocampal cortex; and fusiform gyrus) using a high-resolution in-plane (0.4x0.4 mm) MRI sequence in 30 cognitively normal volunteers (14 APOE-4 carriers, 16 non-carriers, mean age 57 years). A cortical unfolding procedure maximized the visibility of this convoluted cortex, providing cortical ribbon thickness measures throughout individual subregions of the hippocampus and surrounding cortex. APOE-4 carriers had reduced cortical thickness compared with non-carriers in entorhinal cortex (ERC) and the subiculum (Sub), but not in the main hippocampal body or perirhinal cortex. Average cortical thickness was 14.8% lower (p=1.0e(- 6)) for ERC and 12.6% lower (p=6.8e(- 5)) for Sub in APOE-4 carriers. Standard volumetric measures of the same regions showed similar, but non-significant trends. Cognitively intact carriers of APOE-4 show regionally specific thinning of the cortical ribbon compared to APOE-3 carriers; cortical thickness may be a more sensitive measure of pathological differences in genetic risk subjects than standard volumetry.
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Affiliation(s)
- A C Burggren
- David Geffen School of Medicine at UCLA, Center for Cognitive Neurosciences, Semel Institute, 760 Westwood Plaza B8-169, Los Angeles, CA 90095, USA
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32
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Fleischman DA. Repetition priming in aging and Alzheimer's disease: an integrative review and future directions. Cortex 2007; 43:889-97. [PMID: 17941347 DOI: 10.1016/s0010-9452(08)70688-9] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Two decades of research examining repetition priming in aging and Alzheimer's disease (AD) has yielded a large body of contradictory findings due to differences between studies in participant and task characteristics. Recent research that has employed methodological advances indicates that this form of implicit memory is preserved in healthy aging. When a priming deficit does occur in studies of aging, it is likely a very early signal of neurological disease. Future directions for research in this area include linking priming ability to known risk factors for development of AD, integrating priming measures into clinical neuropsychological assessment batteries, and implementing programs of cognitive retraining that enhance memory using stimulus repetition techniques.
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Affiliation(s)
- Debra A Fleischman
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA.
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33
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Knuesel I, Nyffeler M, Mormède C, Muhia M, Meyer U, Pietropaolo S, Yee BK, Pryce CR, LaFerla FM, Marighetto A, Feldon J. Age-related accumulation of Reelin in amyloid-like deposits. Neurobiol Aging 2007; 30:697-716. [PMID: 17904250 DOI: 10.1016/j.neurobiolaging.2007.08.011] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2007] [Revised: 07/23/2007] [Accepted: 08/13/2007] [Indexed: 01/24/2023]
Abstract
Accumulating evidence suggest that alterations in Reelin-mediated signaling may contribute to neuronal dysfunction associated with Alzheimer's disease (AD), the most common form of senile dementia. However, limited information is available on the effect of age, the major risk factor of AD, on Reelin expression. Here, we report that normal aging in rodents and primates is accompanied by accumulation of Reelin-enriched proteinous aggregates in the hippocampal formation that are related to the loss of Reelin-expressing neurons. Both phenomena are associated with age-related memory impairments in wild-type mice. We provide evidence that normal aging involves loss of Reelin neurons, reduced production and elimination of the extracellular deposits, whereas a prenatal immune challenge or the expression of AD-causing gene products, result in earlier, higher, and more persistent levels of Reelin-positive deposits. These aggregates co-localize with non-fibrillary amyloid-plaques, potentially representing oligomeric Abeta species. Our findings suggest that elevated Reelin plaque load creates a precursor condition for senile plaque deposition and may represent a critical risk factor for sporadic AD.
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Affiliation(s)
- Irene Knuesel
- Institute of Pharmacology and Toxicology, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
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34
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Wierenga CE, Bondi MW. Use of functional magnetic resonance imaging in the early identification of Alzheimer's disease. Neuropsychol Rev 2007; 17:127-43. [PMID: 17476598 PMCID: PMC2084460 DOI: 10.1007/s11065-007-9025-y] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2007] [Accepted: 02/23/2007] [Indexed: 12/19/2022]
Abstract
A growing body of evidence suggests that a preclinical phase of Alzheimer's disease (AD) exists several years or more prior to the overt manifestation of clinical symptoms and is characterized by subtle neuropsychological and brain changes. Identification of individuals prior to the development of significant clinical symptoms is imperative in order to have the greatest treatment impact by maintaining cognitive abilities and preserving quality of life. Functional magnetic resonance imaging (fMRI) offers considerable promise as a non-invasive tool for detecting early functional brain changes in asymptomatic adults. In fact, evidence to date indicates that functional brain decline precedes structural decline in preclinical samples. Therefore, fMRI may offer the unique ability to capture the dynamic state of change in the degenerating brain. This review examines the clinical utility of blood oxygen level dependent (BOLD) fMRI in those at risk for AD as well as in early AD. We provide an overview of fMRI findings in at-risk groups by virtue of genetic susceptibility or mild cognitive decline followed by an appraisal of the methodological issues concerning the diagnostic usefulness of fMRI in early AD. We conclude with a discussion of future directions and propose that BOLD-fMRI in combination with cerebral blood flow or diffusion techniques will provide a more complete accounting of the neurovascular changes that occur in preclinical AD and thus improve our ability to reliably detect early brain changes prior to disease onset.
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Affiliation(s)
- Christina E Wierenga
- Department of Psychiatry, University of California San Diego, La Jolla, California, USA
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35
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Pereira AC, Wu W, Small SA. Imaging-guided microarray: isolating molecular profiles that dissociate Alzheimer's disease from normal aging. Ann N Y Acad Sci 2007; 1097:225-38. [PMID: 17413025 DOI: 10.1196/annals.1379.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Although both Alzheimer's disease (AD) and normal aging contribute to age-related hippocampal dysfunction, they are likely governed by separate molecular mechanisms. In principle, gene expression profiling can offer molecular clues about underlying mechanisms, but in practice techniques like microarray present unique analytic challenges when applied to disorders of the brain. Imaging-guided microarray is an approach designed to address these analytic challenges. Here, we will first review findings applying variants of functional magnetic resonance imaging (fMRI) to AD and normal aging, establishing the spatiotemporal profiles that dissociate one from the other. Then, we will review preliminary findings applying imaging-guided microarray to AD and normal aging, in an attempt to isolate molecular profiles that dissociate the two main causes of age-related hippocampal dysfunction.
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Affiliation(s)
- Ana Carolina Pereira
- Department of Neurology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University College of Physicians and Surgeons, New York, NY 10032, USA
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36
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Schenck JF, Zimmerman EA, Li Z, Adak S, Saha A, Tandon R, Fish KM, Belden C, Gillen RW, Barba A, Henderson DL, Neil W, O'Keefe T. High-field magnetic resonance imaging of brain iron in Alzheimer disease. Top Magn Reson Imaging 2007; 17:41-50. [PMID: 17179896 DOI: 10.1097/01.rmr.0000245455.59912.40] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
OBJECTIVES Increased iron deposition in the brain may occur in several neurodegenerative diseases, including Alzheimer disease (AD). Iron deposits shorten T2 relaxation times on T2-weighted magnetic resonance (MR) images. Iron-dependent contrast increases with magnetic field strength. We hypothesized that T2 mapping using 3 T MR imaging (MRI) can disclose differences between normal controls and AD subjects. METHODS High-resolution brain imaging protocols were developed and applied to 24 AD patients and 20 age-matched controls using 3 T MRI. Eight anatomical regions of interest were manually segmented, and T2 histograms were computed. A visual analysis technique, the heat map, was modified and applied to the large image data sets generated by these protocols. RESULTS A large number (163) of features from these histograms were examined, and 38 of these were significantly different (P < 0.05) between the groups. In the hippocampus, evidence was found for AD-related increases in iron deposition (shortened T2) and in the concentration of free tissue water (lengthened T2). Imaging of a section of postmortem brain before and after chemically extracting the iron established the presence of MRI-detectable iron in the hippocampus, cortex, and white matter in addition to brain regions traditionally viewed as containing high iron concentrations.
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Affiliation(s)
- John F Schenck
- General Electric Global Research Center, Schenectady, NY 12309, USA.
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Abstract
Alzheimer disease (AD) is the most common type of dementia. It currently affects approximately 4 million people in the United States. AD is a progressive neurodegenerative disorder characterized by the gradual deposition of neuritic plaques and neurofibrillary tangles in the brain, which is thought to occur decades before the onset of clinical symptoms. Identification of people at risk before the clinical appearance of dementia has become a priority due to the potential benefits of therapeutic intervention. Although atrophy of medial temporal lobe structures has been shown to correlate with progression of AD, a growing number of recent reports have indicated that such atrophy may not be specific to AD. To improve diagnostic specificity, new quantitative magnetic resonance (MR) imaging methods are being developed that exploit known pathogenic mechanisms exclusive to AD. This article reviews the MR techniques that are currently available for the diagnostic assessment of AD.
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Affiliation(s)
- Anita Ramani
- Center for Biomedical Imaging, Department of Radiology, New York University School of Medicine, New York, NY 10016-3240, USA.
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38
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Abstract
Deciphering the secret of successful aging depends on understanding the patterns and biological underpinnings of cognitive and behavioral changes throughout adulthood. That task is inseparable from comprehending the workings of the brain, the physical substrate of behavior. In this review, we summarize the extant literature on age-related differences and changes in brain structure, including postmortem and noninvasive magnetic resonance imaging (MRI) studies. Among the latter, we survey the evidence from volumetry, diffusion-tensor imaging, and evaluations of white matter hyperintensities (WMH). Further, we review the attempts to elucidate the mechanisms of age-related structural changes by measuring metabolic markers of aging through magnetic resonance spectroscopy (MRS). We discuss the putative links between the pattern of brain aging and the pattern of cognitive decline and stability. We then present examples of activities and conditions (hypertension, hormone deficiency, aerobic fitness) that may influence the course of normal aging in a positive or negative fashion. Lastly, we speculate on several proposed mechanisms of differential brain aging, including neurotransmitter systems, stress and corticosteroids, microvascular changes, calcium homeostasis, and demyelination.
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Affiliation(s)
- Naftali Raz
- Department of Psychology and Institute of Gerontology, Wayne State University, 87 East Ferry St., 226 Knapp Building, Detroit, MI 48202, USA.
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Abstract
Brain cells are highly energy dependent for maintaining ion homeostasis during high metabolic activity. During active periods, full mitochondrial function is essential to generate ATP from electrons that originate with the oxidation of NADH. Decreasing brain metabolism is a significant cause of cognitive abnormalities of Alzheimer disease (AD), but it remains uncertain whether this is the cause of further pathology or whether synaptic loss results in a lower energy demand. Synapses are the first to show pathological symptoms in AD before the onset of clinical symptoms. Because synaptic function has high energy demands, interruption in mitochondrial energy supply could be the major factor in synaptic failure in AD. A newly discovered age-related decline in neuronal NADH and redox ratio may jeopardize this function. Mitochondrial dehydrogenases and several mutations affecting energy transfer are frequently altered in aging and AD. Thus, with the accumulation of genetic defects in mitochondria at the level of energy transfer, the issue of neuronal susceptibility to damage as a function of age and age-related disease becomes important. In an aging rat neuron model, mitochondria are both chronically depolarized and produce more reactive oxygen species with age. These concepts suggest that multiple treatment targets may be needed to reverse this multifactorial disease. This review summarizes new insights based on the interaction of mitoenergetic failure, glutamate excitotoxicity, and amyloid toxicity in the exacerbation of AD.
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Affiliation(s)
- Mordhwaj S Parihar
- Department of Medical Microbiology, Immunology and Cell Biology, Southern Illinois University School of Medicine, Springfield, IL 62794-9626, USA
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Krishnan S, Slavin MJ, Tran TTT, Doraiswamy PM, Petrella JR. Accuracy of spatial normalization of the hippocampus: implications for fMRI research in memory disorders. Neuroimage 2006; 31:560-71. [PMID: 16513371 DOI: 10.1016/j.neuroimage.2005.12.061] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Revised: 11/28/2005] [Accepted: 12/29/2005] [Indexed: 11/21/2022] Open
Abstract
Functional magnetic resonance imaging (fMRI) studies in memory impairment have detected functional alterations in medial temporal lobe (MTL) structures, notably the hippocampus. Many of these studies employ spatial normalization to place subjects in a standardized template space prior to analysis; however, little is known about the effects of local atrophy on the normalization process in structures such as the hippocampus. The purpose of this study was to compare the accuracy of spatial normalization of the hippocampus between memory-impaired patients and controls. Twenty clinically-defined mild cognitive impairment (MCI) subjects and twenty elderly controls were studied at 4T with structural and functional MRI during a memory encoding-retrieval task. Bilateral hippocampal regions-of-interest (ROIs) were manually drawn for all subjects and further divided into anterior/posterior subregions. To assess normalization accuracy to the Montreal Neurological Institute template, the percentage of each template-defined hippocampal ROI originating from true hippocampal tissue was determined for all subjects. To assess the ability of spatial normalization to equalize group differences in hippocampal volume, pre- and post-normalization hippocampal volumes were compared. Finally, fMRI measures from template and non-template analyses were compared. Poorer normalization accuracy of the bilateral hippocampi, particularly the posterior portions, was found for MCI subjects. Significant group differences were found in left hippocampal and bilateral posterior hippocampal volumes, and these differences were not corrected with normalization. Hippocampal volumes were significantly correlated with normalization accuracy across MCI and control groups, but some significant differences in normalization accuracy persisted independent of these volume differences. Template and non-template fMRI analyses were significantly correlated in controls, but not MCI subjects, during memory retrieval. These findings suggest decreased normalization accuracy in memory-impaired subjects is a potentially important confounder of template-based fMRI analyses in the hippocampus and MTL.
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Affiliation(s)
- Sriyesh Krishnan
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
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Hwang DY, Golby AJ. The brain basis for episodic memory: insights from functional MRI, intracranial EEG, and patients with epilepsy. Epilepsy Behav 2006; 8:115-26. [PMID: 16278097 DOI: 10.1016/j.yebeh.2005.09.009] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/14/2005] [Accepted: 09/19/2005] [Indexed: 10/25/2022]
Abstract
This article reviews the contributions that functional magnetic resonance imaging (fMRI), intracranial electroencephalography (iEEG), and patient studies have made to our current understanding of how memory functions arise from the brain. First, we briefly discuss the current classification of different memory systems and their neuroanatomical correlates, focusing on episodic memory and evidence from lesion studies. We then survey both fMRI and iEEG studies of memory function. For each modality, we discuss its physiological basis, as well as point out key studies that have led to new insights regarding memory. Advantages and disadvantages of each brain mapping modality are addressed. Wherever appropriate, we point out implications these studies have for the treatment of patients with epilepsy. We conclude this review with further discussion regarding the potential for combining fMRI and iEEG techniques in future investigations of memory function.
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Small SA, Kent K, Pierce A, Leung C, Kang MS, Okada H, Honig L, Vonsattel JP, Kim TW. Model-guided microarray implicates the retromer complex in Alzheimer's disease. Ann Neurol 2006; 58:909-19. [PMID: 16315276 DOI: 10.1002/ana.20667] [Citation(s) in RCA: 318] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Although, in principle, gene expression profiling is well suited to isolate pathogenic molecules associated with Alzheimer's disease (AD), techniques such as microarray present unique analytic challenges when applied to disorders of the brain. Here, we addressed these challenges by first constructing a spatiotemporal model, predicting a priori how a molecule underlying AD should behave anatomically and over time. Then, guided by the model, we generated gene expression profiles of the entorhinal cortex and the dentate gyrus, harvested from the brains of AD cases and controls covering a broad age span. Among many expression differences, the retromer trafficking molecule VPS35 best conformed to the spatiotemporal model of AD. Western blotting confirmed the abnormality, establishing that VPS35 levels are reduced in brain regions selectively vulnerable to AD. VPS35 is the core molecule of the retromer trafficking complex and further analysis revealed that VPS26, another member of the complex, is also downregulated in AD. Cell culture studies, using small interfering RNAs or expression vectors, showed that VPS35 regulates Abeta peptide levels, establishing the relevance of the retromer complex to AD. Reviewing our findings in the context of recent studies suggests how downregulation of the retromer complex in AD can regulate local levels of Abeta peptide.
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Affiliation(s)
- Scott A Small
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Department of Neurology, and the Center for Neurobiology and Behavior, Columbia University College of Physicians and Surgeons, New York, NY, USA.
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Krishnan S, Talley BD, Slavin MJ, Doraiswamy PM, Petrella JR. Current Status of Functional MR Imaging, Perfusion-Weighted Imaging, and Diffusion-Tensor Imaging in Alzheimer's Disease Diagnosis and Research. Neuroimaging Clin N Am 2005; 15:853-68, xi. [PMID: 16443496 DOI: 10.1016/j.nic.2005.09.011] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Advanced MR techniques, such as functional MR imaging, perfusion-weighted imaging, and diffusion-tensor imaging, offer the capability of detecting early functional, hemodynamic, and microstructural alterations in Alzheimer's disease before gross anatomic alterations. Most studies of these emerging technologies are at the exploratory stage, with the purpose of increasing understanding of the underlying disease process and defining cross-sectional differences across various subject populations. Assessment of the diagnostic efficacy of these technologies in detecting early Alzheimer's disease in its preclinical and prodromal stages is ongoing.
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Affiliation(s)
- Sriyesh Krishnan
- Department of Radiology, Duke University Medical Center, Durham, NC 27710, USA
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Haacke EM, Cheng NYC, House MJ, Liu Q, Neelavalli J, Ogg RJ, Khan A, Ayaz M, Kirsch W, Obenaus A. Imaging iron stores in the brain using magnetic resonance imaging. Magn Reson Imaging 2005; 23:1-25. [PMID: 15733784 DOI: 10.1016/j.mri.2004.10.001] [Citation(s) in RCA: 725] [Impact Index Per Article: 38.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2004] [Accepted: 10/07/2004] [Indexed: 02/06/2023]
Abstract
For the last century, there has been great physiological interest in brain iron and its role in brain function and disease. It is well known that iron accumulates in the brain for people with Huntington's disease, Parkinson's disease, Alzheimer's disease, multiple sclerosis, chronic hemorrhage, cerebral infarction, anemia, thalassemia, hemochromatosis, Hallervorden-Spatz, Down syndrome, AIDS and in the eye for people with macular degeneration. Measuring the amount of nonheme iron in the body may well lead to not only a better understanding of the disease progression but an ability to predict outcome. As there are many forms of iron in the brain, separating them and quantifying each type have been a major challenge. In this review, we present our understanding of attempts to measure brain iron and the potential of doing so with magnetic resonance imaging. Specifically, we examine the response of the magnetic resonance visible iron in tissue that produces signal changes in both magnitude and phase images. These images seem to correlate with brain iron content, perhaps ferritin specifically, but still have not been successfully exploited to accurately and precisely quantify brain iron. For future quantitative studies of iron content we propose four methods: correlating R2' and phase to iron content; applying a special filter to the phase to obtain a susceptibility map; using complex analysis to extract the product of susceptibility and volume content of the susceptibility source; and using early and late echo information to separately predict susceptibility and volume content.
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Affiliation(s)
- E Mark Haacke
- The MRI Institute for Biomedical Research, 440 East Ferry Street, Detroit, MI 48202, USA.
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Fleischman DA, Wilson RS, Gabrieli JDE, Bienias JL, Bennett DA. A longitudinal study of implicit and explicit memory in old persons. Psychol Aging 2005; 19:617-25. [PMID: 15584787 DOI: 10.1037/0882-7974.19.4.617] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Decline in explicit memory with advancing age is a common finding, but it is unclear whether implicit memory (repetition priming) declines or remains stable. Meta-analyses of studies that examined differences between extreme groups (young-old), typically at a single point in time and on a single test, suggest that a mild reduction in priming occurs with advancing age. The authors examined explicit memory and priming, on multiple tests over 4 annual data-collection waves, in a large group of older persons without dementia at baseline. Explicit memory declined significantly, but priming remained stable. Findings indicate that explicit memory and priming are dissociable on the basis of age-related change and that mildly reduced priming is not an inevitable consequence of growing older.
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Affiliation(s)
- Debra A Fleischman
- Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL 60612, USA.
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Head D, Snyder AZ, Girton LE, Morris JC, Buckner RL. Frontal-Hippocampal Double Dissociation Between Normal Aging and Alzheimer's Disease. Cereb Cortex 2004; 15:732-9. [PMID: 15371293 DOI: 10.1093/cercor/bhh174] [Citation(s) in RCA: 119] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Controversy persists regarding whether Alzheimer's disease (AD) is a distinct entity or instead exists on a continuum with nondemented aging. To explore this issue, volumetric analyses of callosal and hippocampal regions were performed on 150 participants aged 18-93 years. Group-level analyses revealed that nondemented age-related differences were greater in anterior than posterior callosal regions and were not augmented by early-stage AD. In contrast, early-stage AD was associated with substantial reduction in hippocampal volume. Examination of the 100 older adults using regression analyses demonstrated age-associated differences in callosal volume that were similar in demented and nondemented individuals. Early-stage AD was again characterized by a marked reduction in hippocampal volume while age alone induced only mild differences in hippocampal volume. As a final analysis, the formal double dissociation was confirmed by comparing the effects of age directly against the effects of dementia. These results suggest a multiple-component model of aging. One process, associated with AD, manifests early and prominently in the medial temporal lobe. A separate process, ubiquitous in aging, affects brain white matter with an anterior-to-posterior gradient and may underlie the executive difficulties common in aging.
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Affiliation(s)
- Denise Head
- Howard Hughes Medical Institute, One Brookings Drive, Department of Psychology, Washington University, St Louis, MO 63130, USA.
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47
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Abstract
Memory decline in aging results from multiple factors that influence both executive function and the medial temporal lobe memory system. In advanced aging, frontal-striatal systems are preferentially vulnerable to white matter change, atrophy, and certain forms of neurotransmitter depletion. Frontal-striatal change may underlie mild memory difficulties in aging that are most apparent on tasks demanding high levels of attention and controlled processing. Through separate mechanisms, Alzheimer's disease preferentially affects the medial temporal lobe and cortical networks, including posterior cingulate and retrosplenial cortex early in its progression, often before clinical symptoms are recognized. Disruption of the medial temporal lobe memory system leads directly to memory impairment. Recent findings further suggest that age-associated change is not received passively. Reliance on reserve is emerging as an important factor that determines who ages gracefully and who declines rapidly. Functional imaging studies, in particular, suggest increased recruitment of brain areas in older adults that may reflect a form of compensation.
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Affiliation(s)
- Randy L Buckner
- Howard Hughes Medical Institute, Washington University in St. Louis, Department of Psychology, One Brookings Drive, Campus Box 1125, St. Louis, MO 63130, USA.
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Pierce A, Small SA. Combining brain imaging with microarray: isolating molecules underlying the physiologic disorders of the brain. Neurochem Res 2004; 29:1145-52. [PMID: 15176471 DOI: 10.1023/b:nere.0000023601.50101.7f] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Many diseases of the nervous system cause dysfunction by impairing neuronal physiology more than by altering brain anatomy--including age-related cognitive decline, most psychiatric disorders, and even the earliest stages of Alzheimer's disease. The absence of clear anatomical markers makes it difficult to identify targeted cells, which in turn impedes attempts to isolate the pathogenic molecules that cause physiologic disruption. Here we show how brain imaging and microarray can be used as complimentary techniques that together can characterize the cellular and molecular aspects of this class of diseases.
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Affiliation(s)
- Aimee Pierce
- The Taub Institute on Alzheimer's Disease and the Aging Brain, the Center for Neurobiology and Behavior, and the Department of Neurology, Columbia University, College of Physicians and Surgeons, New York, New York 10032, USA
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Hedden T, Gabrieli JDE. Insights into the ageing mind: a view from cognitive neuroscience. Nat Rev Neurosci 2004; 5:87-96. [PMID: 14735112 DOI: 10.1038/nrn1323] [Citation(s) in RCA: 1349] [Impact Index Per Article: 67.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Trey Hedden
- Stanford University, Psychology Department, 434 Jordan Hall, Building 420, Stanford, California 94305-2130, USA.
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Rosen AC, Prull MW, Gabrieli JDE, Stoub T, O'Hara R, Friedman L, Yesavage JA, deToledo-Morrell L. Differential associations between entorhinal and hippocampal volumes and memory performance in older adults. Behav Neurosci 2004; 117:1150-60. [PMID: 14674836 DOI: 10.1037/0735-7044.117.6.1150] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Magnetic resonance imaging-derived entorhinal and hippocampal volumes were measured in 14 nondemented, community-dwelling older adults. Participants were selected so that memory scores from 2 years prior to scanning varied widely but were not deficient relative to age-appropriate norms. A median split of these memory scores defined high-memory and low-memory groups. Verbal memory scores at the time of imaging were lower, and entorhinal and hippocampal volumes were smaller, in the low-memory group than in the high-memory group. Left entorhinal cortex volume showed the strongest correlation (r= .79) with immediate recall of word lists. Left hippocampal volume showed the strongest correlation (r= .57) with delayed paragraph recall. These results suggest that entorhinal and hippocampal volumes are related to individual differences in dissociable kinds of memory performance among healthy older adults.
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Affiliation(s)
- Allyson C Rosen
- Department of Psychology, Stanford University, Stanford, California 94305, USA.
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