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Félix J, Díaz-Del Cerro E, Garrido A, De La Fuente M. Characterization of a natural model of adult mice with different rate of aging. Mech Ageing Dev 2024; 222:111991. [PMID: 39278278 DOI: 10.1016/j.mad.2024.111991] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2024] [Revised: 07/30/2024] [Accepted: 09/09/2024] [Indexed: 09/18/2024]
Abstract
Aging is a heterogeneous process, so individuals of the same age may be aging at a different rate. A natural model of premature aging in mice have been proposed based on the poor response to the T-maze. Those that take longer to cross the intersection are known as Prematurely Aging Mice (PAM), while those that show an exceptional response are known as Exceptional non-PAM (E-NPAM), being the rest non-PAM (NPAM). Although many aspects of PAM and E-NPAM have been described, some aspects of their brain aging have not been studied. Similarly, it is known that PAM, NPAM and E-NPAM show a different rate of aging and longevity, but the differences between these three groups in behavior, immune function and oxidative-inflammatory state are unknown. The present study aims to deepen the study of brain aging in PAM and E-NPAM, and to study the differences in behavior, immunity, and oxidative-inflammatory state of peritoneal leukocytes between PAM, NPAM and E-NPAM. Results show deteriorated brains in PAM. Moreover, NPAM show an oxidative state similar to E-NPAM, an anxiety similar to PAM, and an intermediate immunity and lifespan between PAM and E-NPAM. In conclusion, immune function seems to be more associated with the longevity achieved.
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Affiliation(s)
- Judith Félix
- Department of Genetics, Physiology and Microbiology (Animal Physiology Unit), Faculty of Biological Sciences, Complutense University of Madrid, Spain; Institute of Investigation Hospital 12 Octubre (imas12), Madrid, Spain.
| | - Estefanía Díaz-Del Cerro
- Department of Genetics, Physiology and Microbiology (Animal Physiology Unit), Faculty of Biological Sciences, Complutense University of Madrid, Spain; Institute of Investigation Hospital 12 Octubre (imas12), Madrid, Spain.
| | - Antonio Garrido
- Institute of Investigation Hospital 12 Octubre (imas12), Madrid, Spain; Department of Biosciences, School of Biomedical and Health Sciences, Universidad Europea de Madrid (UEM), Villaviciosa de Odón, Madrid, Spain.
| | - Mónica De La Fuente
- Department of Genetics, Physiology and Microbiology (Animal Physiology Unit), Faculty of Biological Sciences, Complutense University of Madrid, Spain; Institute of Investigation Hospital 12 Octubre (imas12), Madrid, Spain.
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2
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Bennett HC, Zhang Q, Wu YT, Manjila SB, Chon U, Shin D, Vanselow DJ, Pi HJ, Drew PJ, Kim Y. Aging drives cerebrovascular network remodeling and functional changes in the mouse brain. Nat Commun 2024; 15:6398. [PMID: 39080289 PMCID: PMC11289283 DOI: 10.1038/s41467-024-50559-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Accepted: 07/15/2024] [Indexed: 08/02/2024] Open
Abstract
Aging is frequently associated with compromised cerebrovasculature and pericytes. However, we do not know how normal aging differentially impacts vascular structure and function in different brain areas. Here we utilize mesoscale microscopy methods and in vivo imaging to determine detailed changes in aged murine cerebrovascular networks. Whole-brain vascular tracing shows an overall ~10% decrease in vascular length and branching density with ~7% increase in vascular radii in aged brains. Light sheet imaging with 3D immunolabeling reveals increased arteriole tortuosity of aged brains. Notably, vasculature and pericyte densities show selective and significant reductions in the deep cortical layers, hippocampal network, and basal forebrain areas. We find increased blood extravasation, implying compromised blood-brain barrier function in aged brains. Moreover, in vivo imaging in awake mice demonstrates reduced baseline and on-demand blood oxygenation despite relatively intact neurovascular coupling. Collectively, we uncover regional vulnerabilities of cerebrovascular network and physiological changes that can mediate cognitive decline in normal aging.
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Affiliation(s)
- Hannah C Bennett
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Qingguang Zhang
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Physiology, Michigan State University, East Lansing, MI, 48824, USA
| | - Yuan-Ting Wu
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
- Department of Neurosurgery, Department of Computational Biomedicine, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA
| | - Steffy B Manjila
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Uree Chon
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
- Neurosciences Graduate Program, Stanford University, Stanford, CA, 94305, USA
| | - Donghui Shin
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Daniel J Vanselow
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Hyun-Jae Pi
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Patrick J Drew
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
- Department of Biomedical Engineering, Biology, and Neurosurgery, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Yongsoo Kim
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA.
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA.
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3
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Jullienne A, Szu JI, Quan R, Trinh MV, Norouzi T, Noarbe BP, Bedwell AA, Eldridge K, Persohn SC, Territo PR, Obenaus A. Cortical cerebrovascular and metabolic perturbations in the 5xFAD mouse model of Alzheimer's disease. Front Aging Neurosci 2023; 15:1220036. [PMID: 37533765 PMCID: PMC10392850 DOI: 10.3389/fnagi.2023.1220036] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 07/03/2023] [Indexed: 08/04/2023] Open
Abstract
Introduction The 5xFAD mouse is a popular model of familial Alzheimer's disease (AD) that is characterized by early beta-amyloid (Aβ) deposition and cognitive decrements. Despite numerous studies, the 5xFAD mouse has not been comprehensively phenotyped for vascular and metabolic perturbations over its lifespan. Methods Male and female 5xFAD and wild type (WT) littermates underwent in vivo 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) imaging at 4, 6, and 12 months of age to assess regional glucose metabolism. A separate cohort of mice (4, 8, 12 months) underwent "vessel painting" which labels all cerebral vessels and were analyzed for vascular characteristics such as vessel density, junction density, vessel length, network complexity, number of collaterals, and vessel diameter. Results With increasing age, vessels on the cortical surface in both 5xFAD and WT mice showed increased vessel length, vessel and junction densities. The number of collateral vessels between the middle cerebral artery (MCA) and the anterior and posterior cerebral arteries decreased with age but collateral diameters were significantly increased only in 5xFAD mice. MCA total vessel length and junction density were decreased in 5xFAD mice compared to WT at 4 months. Analysis of 18F-FDG cortical uptake revealed significant differences between WT and 5xFAD mice spanning 4-12 months. Broadly, 5xFAD males had significantly increased 18F-FDG uptake at 12 months compared to WT mice. In most cortical regions, female 5xFAD mice had reduced 18F-FDG uptake compared to WT across their lifespan. Discussion While the 5xFAD mouse exhibits AD-like cognitive deficits as early as 4 months of age that are associated with increasing Aβ deposition, we only found significant differences in cortical vascular features in males, not in females. Interestingly, 5xFAD male and female mice exhibited opposite effects in 18F-FDG uptake. The MCA supplies blood to large portions of the somatosensory cortex and portions of motor and visual cortex and increased vessel length alongside decreased collaterals which coincided with higher metabolic rates in 5xFAD mice. Thus, a potential mismatch between metabolic demand and vascular delivery of nutrients in the face of increasing Aβ deposition could contribute to the progressive cognitive deficits seen in the 5xFAD mouse model.
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Affiliation(s)
- Amandine Jullienne
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Jenny I. Szu
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Ryan Quan
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Michelle V. Trinh
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Tannoz Norouzi
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Brenda P. Noarbe
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
| | - Amanda A. Bedwell
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Kierra Eldridge
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Scott C. Persohn
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Paul R. Territo
- Stark Neurosciences Research Institute, School of Medicine, Indiana University, Indianapolis, IN, United States
- Department of Medicine, School of Medicine, Indiana University, Indianapolis, IN, United States
| | - Andre Obenaus
- Department of Pediatrics, School of Medicine, University of California, Irvine, Irvine, CA, United States
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Bennett HC, Zhang Q, Wu YT, Chon U, Pi HJ, Drew PJ, Kim Y. Aging drives cerebrovascular network remodeling and functional changes in the mouse brain. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.05.23.541998. [PMID: 37305850 PMCID: PMC10257218 DOI: 10.1101/2023.05.23.541998] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Aging is the largest risk factor for neurodegenerative disorders, and commonly associated with compromised cerebrovasculature and pericytes. However, we do not know how normal aging differentially impacts the vascular structure and function in different brain areas. Here we utilize mesoscale microscopy methods (serial two-photon tomography and light sheet microscopy) and in vivo imaging (wide field optical spectroscopy and two-photon imaging) to determine detailed changes in aged cerebrovascular networks. Whole-brain vascular tracing showed an overall ~10% decrease in vascular length and branching density, and light sheet imaging with 3D immunolabeling revealed increased arteriole tortuosity in aged brains. Vasculature and pericyte densities showed significant reductions in the deep cortical layers, hippocampal network, and basal forebrain areas. Moreover, in vivo imaging in awake mice identified delays in neurovascular coupling and disrupted blood oxygenation. Collectively, we uncover regional vulnerabilities of cerebrovascular network and physiological changes that can mediate cognitive decline in normal aging.
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Affiliation(s)
- Hannah C Bennett
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
- Equal contribution
| | - Qingguang Zhang
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
- Equal contribution
| | - Yuan-Ting Wu
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Uree Chon
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Hyun-Jae Pi
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
| | - Patrick J Drew
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
- Biomedical Engineering, Biology, and Neurosurgery, The Pennsylvania State University, University Park, PA, 16802, USA
| | - Yongsoo Kim
- Department of Neural and Behavioral Sciences, The Pennsylvania State University, Hershey, PA, 17033, USA
- Center for Neural Engineering, Department of Engineering Science and Mechanics, The Pennsylvania State University, University Park, PA, 16802, USA
- Lead contact
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Brain Macro-Structural Alterations in Aging Rats: A Longitudinal Lifetime Approach. Cells 2023; 12:cells12030432. [PMID: 36766774 PMCID: PMC9914014 DOI: 10.3390/cells12030432] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2022] [Revised: 01/25/2023] [Accepted: 01/26/2023] [Indexed: 02/03/2023] Open
Abstract
Aging is accompanied by macro-structural alterations in the brain that may relate to age-associated cognitive decline. Animal studies could allow us to study this relationship, but so far it remains unclear whether their structural aging patterns correspond to those in humans. Therefore, by applying magnetic resonance imaging (MRI) and deformation-based morphometry (DBM), we longitudinally screened the brains of male RccHan:WIST rats for structural changes across their average lifespan. By combining dedicated region of interest (ROI) and voxel-wise approaches, we observed an increase in their global brain volume that was superimposed by divergent local morphologic alterations, with the largest aging effects in early and middle life. We detected a modality-dependent vulnerability to shrinkage across the visual, auditory, and somato-sensory cortical areas, whereas the piriform cortex showed partial resistance. Furthermore, shrinkage emerged in the amygdala, subiculum, and flocculus as well as in frontal, parietal, and motor cortical areas. Strikingly, we noticed the preservation of ectorhinal, entorhinal, retrosplenial, and cingulate cortical regions, which all represent higher-order brain areas and extraordinarily grew with increasing age. We think that the findings of this study will further advance aging research and may contribute to the establishment of interventional approaches to preserve cognitive health in advanced age.
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6
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Gonzales MM, Garbarino VR, Pollet E, Palavicini JP, Kellogg DL, Kraig E, Orr ME. Biological aging processes underlying cognitive decline and neurodegenerative disease. J Clin Invest 2022; 132:e158453. [PMID: 35575089 PMCID: PMC9106343 DOI: 10.1172/jci158453] [Citation(s) in RCA: 71] [Impact Index Per Article: 35.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease and related dementias (ADRD) are among the top contributors to disability and mortality in later life. As with many chronic conditions, aging is the single most influential factor in the development of ADRD. Even among older adults who remain free of dementia throughout their lives, cognitive decline and neurodegenerative changes are appreciable with advancing age, suggesting shared pathophysiological mechanisms. In this Review, we provide an overview of changes in cognition, brain morphology, and neuropathological protein accumulation across the lifespan in humans, with complementary and mechanistic evidence from animal models. Next, we highlight selected aging processes that are differentially regulated in neurodegenerative disease, including aberrant autophagy, mitochondrial dysfunction, cellular senescence, epigenetic changes, cerebrovascular dysfunction, inflammation, and lipid dysregulation. We summarize research across clinical and translational studies to link biological aging processes to underlying ADRD pathogenesis. Targeting fundamental processes underlying biological aging may represent a yet relatively unexplored avenue to attenuate both age-related cognitive decline and ADRD. Collaboration across the fields of geroscience and neuroscience, coupled with the development of new translational animal models that more closely align with human disease processes, is necessary to advance novel therapeutic discovery in this realm.
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Affiliation(s)
- Mitzi M. Gonzales
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases
- Department of Neurology
| | | | - Erin Pollet
- Glenn Biggs Institute for Alzheimer’s and Neurodegenerative Diseases
| | - Juan P. Palavicini
- Barshop Institute for Longevity and Aging Studies, and
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Dean L. Kellogg
- Barshop Institute for Longevity and Aging Studies, and
- Department of Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
- Geriatric Research and Education Center, South Texas Veterans Health Care System, San Antonio, Texas, USA
| | - Ellen Kraig
- Barshop Institute for Longevity and Aging Studies, and
- Department of Cell Systems and Anatomy, University of Texas Health Science Center at San Antonio, San Antonio, Texas, USA
| | - Miranda E. Orr
- Gerontology and Geriatric Medicine, Wake Forest School of Medicine, Winston-Salem, North Carolina, USA
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7
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Ahn K, Lee SJ, Mook-Jung I. White matter-associated microglia: New players in brain aging and neurodegenerative diseases. Ageing Res Rev 2022; 75:101574. [PMID: 35093614 DOI: 10.1016/j.arr.2022.101574] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2021] [Revised: 12/09/2021] [Accepted: 01/24/2022] [Indexed: 12/20/2022]
Abstract
There has been growing interest in brain aging and rejuvenation. It is well known that brain aging is one of the leading causes of neurodegenerative diseases, such as Alzheimer's disease, but brain aging alone can cause cognitive decline. Microglia are thought to act as 'conductors' of white matter aging by modulating diverse glial cells and phagocytosing white matter-derived myelin debris. A recent study identified a specific subpopulation of microglia in the white matter of aged mice, termed white matter-associated microglia (WAM). Additionally, senescent microglia show impaired phagocytic function and altered lipid metabolism, which cause accumulation of lipid metabolites and eventually lead to myelin sheath degeneration. These results suggest that senescent WAM could be pivotal players in axonal loss during brain aging. The aim of this review is to assess the current state of knowledge on brain aging, with an emphasis on the roles of the white matter and microglia, and suggest potential approaches for rejuvenating the aged brain.
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Affiliation(s)
- Kyusik Ahn
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea
| | - Seung-Jae Lee
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea; Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; SNU Dementia Research Center, Seoul National University College of Medicine, Seoul 03080, Korea
| | - Inhee Mook-Jung
- Department of Biomedical Sciences, College of Medicine, Seoul National University, Seoul 03080, Republic of Korea; Neuroscience Research Institute, Seoul National University College of Medicine, Seoul 03080, Republic of Korea; SNU Dementia Research Center, Seoul National University College of Medicine, Seoul 03080, Korea.
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8
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Neuroimaging of Mouse Models of Alzheimer’s Disease. Biomedicines 2022; 10:biomedicines10020305. [PMID: 35203515 PMCID: PMC8869427 DOI: 10.3390/biomedicines10020305] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/25/2022] [Accepted: 01/25/2022] [Indexed: 12/23/2022] Open
Abstract
Magnetic resonance imaging (MRI) and positron emission tomography (PET) have made great strides in the diagnosis and our understanding of Alzheimer’s Disease (AD). Despite the knowledge gained from human studies, mouse models have and continue to play an important role in deciphering the cellular and molecular evolution of AD. MRI and PET are now being increasingly used to investigate neuroimaging features in mouse models and provide the basis for rapid translation to the clinical setting. Here, we provide an overview of the human MRI and PET imaging landscape as a prelude to an in-depth review of preclinical imaging in mice. A broad range of mouse models recapitulate certain aspects of the human AD, but no single model simulates the human disease spectrum. We focused on the two of the most popular mouse models, the 3xTg-AD and the 5xFAD models, and we summarized all known published MRI and PET imaging data, including contrasting findings. The goal of this review is to provide the reader with broad framework to guide future studies in existing and future mouse models of AD. We also highlight aspects of MRI and PET imaging that could be improved to increase rigor and reproducibility in future imaging studies.
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9
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Fowler C, Goerzen D, Madularu D, Devenyi GA, Chakravarty MM, Near J. Longitudinal characterization of neuroanatomical changes in the Fischer 344 rat brain during normal aging and between sexes. Neurobiol Aging 2022; 109:216-228. [PMID: 34775212 DOI: 10.1016/j.neurobiolaging.2021.10.003] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Revised: 08/23/2021] [Accepted: 10/07/2021] [Indexed: 10/20/2022]
Abstract
Animal models are widely used to study the pathophysiology of disease and to evaluate the efficacy of novel interventions, crucial steps towards improving disease outcomes in humans. The Fischer 344 (F344) wildtype rat is a common experimental background strain for transgenic models of disease and is one of the most frequently used models in aging research. Despite frequency of use, characterization of agerelated neuroanatomical change has not been performed in the F344 rat. To this end, we present a comprehensive longitudinal examination of morphometric change in 73 brain regions and at a voxel-wise level during normative aging in vivo in a mixed-sexcohort of F344 rats. We identified the greatest vulnerability to aging within the cortex, caudoputamen, hindbrain, and internal capsule, while the influence of sex was strongest in the caudoputamen, hippocampus, nucleus accumbens, and thalamus, many of which are implicated in memory and motor control circuits frequently affected by aging and neurodegenerative disease. These findings provide a baseline for neuroanatomical changes associated with aging in male and female F344 rats, to which data from transgenic models or other background strains can be compared.
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Affiliation(s)
- Caitlin Fowler
- Department of Biological and Biomedical Engineering, McGill University, Montreal, Quebec, Canada; Centre d'Imagerie Cérébrale, Douglas Mental Health University Institute, Montreal, Quebec, Canada.
| | - Dana Goerzen
- Centre d'Imagerie Cérébrale, Douglas Mental Health University Institute, Montreal, Quebec, Canada.
| | - Dan Madularu
- Centre d'Imagerie Cérébrale, Douglas Mental Health University Institute, Montreal, Quebec, Canada; Center for Translational NeuroImaging, Northeastern University, Boston, MA, USA; Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Gabriel A Devenyi
- Centre d'Imagerie Cérébrale, Douglas Mental Health University Institute, Montreal, Quebec, Canada; Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - M Mallar Chakravarty
- Department of Biological and Biomedical Engineering, McGill University, Montreal, Quebec, Canada; Centre d'Imagerie Cérébrale, Douglas Mental Health University Institute, Montreal, Quebec, Canada; Department of Psychiatry, McGill University, Montreal, Quebec, Canada
| | - Jamie Near
- Department of Biological and Biomedical Engineering, McGill University, Montreal, Quebec, Canada; Centre d'Imagerie Cérébrale, Douglas Mental Health University Institute, Montreal, Quebec, Canada; Department of Psychiatry, McGill University, Montreal, Quebec, Canada
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10
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Fowler CF, Goerzen D, Devenyi GA, Madularu D, Chakravarty MM, Near J. OUP accepted manuscript. Brain Commun 2022; 4:fcac072. [PMID: 35434622 PMCID: PMC9007326 DOI: 10.1093/braincomms/fcac072] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 01/12/2022] [Accepted: 03/16/2022] [Indexed: 11/13/2022] Open
Affiliation(s)
- Caitlin F. Fowler
- Department of Biological and Biomedical Engineering, McGill University, Duff Medical Building, Montreal, Canada H3A 2B4
- Centre d’Imagerie Cérébrale, Douglas Mental Health University Institute, Verdun, Canada H4H 1R3
- Correspondence to: Caitlin F. Fowler, CIC Pavilion Office GH-2113 Douglas Mental Health University Institute 6875 Boulevard LaSalle Montreal, Canada H4H 1R3 E-mail:
| | - Dana Goerzen
- Centre d’Imagerie Cérébrale, Douglas Mental Health University Institute, Verdun, Canada H4H 1R3
| | - Gabriel A. Devenyi
- Centre d’Imagerie Cérébrale, Douglas Mental Health University Institute, Verdun, Canada H4H 1R3
- Department of Psychiatry, McGill University, Montreal, Canada H3A 1A1
| | - Dan Madularu
- Centre for Translational NeuroImaging, Northeastern University, Boston, USA
| | - M. Mallar Chakravarty
- Department of Biological and Biomedical Engineering, McGill University, Duff Medical Building, Montreal, Canada H3A 2B4
- Centre d’Imagerie Cérébrale, Douglas Mental Health University Institute, Verdun, Canada H4H 1R3
- Department of Psychiatry, McGill University, Montreal, Canada H3A 1A1
| | - Jamie Near
- Department of Biological and Biomedical Engineering, McGill University, Duff Medical Building, Montreal, Canada H3A 2B4
- Centre d’Imagerie Cérébrale, Douglas Mental Health University Institute, Verdun, Canada H4H 1R3
- Department of Psychiatry, McGill University, Montreal, Canada H3A 1A1
- Physical Studies Research Platform, Sunnybrook Research Institute, Toronto, Canada M4N 3M5
- Department of Medical Biophysics, University of Toronto, Toronto, Canada M5G 1L7
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11
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Ni R. Magnetic Resonance Imaging in Animal Models of Alzheimer's Disease Amyloidosis. Int J Mol Sci 2021; 22:12768. [PMID: 34884573 PMCID: PMC8657987 DOI: 10.3390/ijms222312768] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/18/2021] [Accepted: 11/23/2021] [Indexed: 02/07/2023] Open
Abstract
Amyloid-beta (Aβ) plays an important role in the pathogenesis of Alzheimer's disease. Aberrant Aβ accumulation induces neuroinflammation, cerebrovascular alterations, and synaptic deficits, leading to cognitive impairment. Animal models recapitulating the Aβ pathology, such as transgenic, knock-in mouse and rat models, have facilitated the understanding of disease mechanisms and the development of therapeutics targeting Aβ. There is a rapid advance in high-field MRI in small animals. Versatile high-field magnetic resonance imaging (MRI) sequences, such as diffusion tensor imaging, arterial spin labeling, resting-state functional MRI, anatomical MRI, and MR spectroscopy, as well as contrast agents, have been developed for preclinical imaging in animal models. These tools have enabled high-resolution in vivo structural, functional, and molecular readouts with a whole-brain field of view. MRI has been used to visualize non-invasively the Aβ deposits, synaptic deficits, regional brain atrophy, impairment in white matter integrity, functional connectivity, and cerebrovascular and glymphatic system in animal models of Alzheimer's disease amyloidosis. Many of the readouts are translational toward clinical MRI applications in patients with Alzheimer's disease. In this review, we summarize the recent advances in MRI for visualizing the pathophysiology in amyloidosis animal models. We discuss the outstanding challenges in brain imaging using MRI in small animals and propose future outlook in visualizing Aβ-related alterations in the brains of animal models.
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Affiliation(s)
- Ruiqing Ni
- Institute for Biomedical Engineering, ETH Zurich & University of Zurich, 8093 Zurich, Switzerland;
- Institute for Regenerative Medicine, University of Zurich, 8952 Zurich, Switzerland
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12
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Pursuit of precision medicine: Systems biology approaches in Alzheimer's disease mouse models. Neurobiol Dis 2021; 161:105558. [PMID: 34767943 PMCID: PMC10112395 DOI: 10.1016/j.nbd.2021.105558] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 11/05/2021] [Accepted: 11/08/2021] [Indexed: 12/12/2022] Open
Abstract
Alzheimer's disease (AD) is a complex disease that is mediated by numerous factors and manifests in various forms. A systems biology approach to studying AD involves analyses of various body systems, biological scales, environmental elements, and clinical outcomes to understand the genotype to phenotype relationship that potentially drives AD development. Currently, there are many research investigations probing how modifiable and nonmodifiable factors impact AD symptom presentation. This review specifically focuses on how imaging modalities can be integrated into systems biology approaches using model mouse populations to link brain level functional and structural changes to disease onset and progression. Combining imaging and omics data promotes the classification of AD into subtypes and paves the way for precision medicine solutions to prevent and treat AD.
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13
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Mun J, Jung J, Park C. Effects of cerebral hypoperfusion on the cerebral white matter: a meta‑analysis. Acta Neurobiol Exp (Wars) 2021; 81:295-306. [PMID: 34672300 DOI: 10.21307/ane-2021-029] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Decreased cerebral blood flow (CBF) in aging is known to induce aging‑related cerebral deteriorations, such as neuronal degeneration, white matter (WM) alterations, and vascular deformations. However, the effects of cerebral hypoperfusion on WM alterations remain unclear. This study investigates the relationship between cerebral hypoperfusion and WM total volume changes by assessing the trends in CBF and WM changes by meta‑analysis. In this meta‑analysis, the differences in CBF were compared according to cerebral hypoperfusion type and the effect of cerebral hypoperfusion on the total volume of WM changes in rodents. Using subgroup analysis, 13 studies were evaluated for comparing CBF according to the type of cerebral hypoperfusion; 12 studies were evaluated for comparing the effects of cerebral hypoperfusion on the total volume of WM changes. Our meta‑analysis shows that the total volume of WM decreases with a decrease in CBF. However, the reduction in\r\nthe total volume of WM was greater in normal aging mice than in the cerebral hypoperfusion model mice. These results suggest that the reduction of cerebral WM volume during the aging process is affected by other factors in addition to a decrease in CBF.
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Affiliation(s)
- Juyeon Mun
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Junyang Jung
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea
| | - Chan Park
- Department of Biomedical Science, Graduate School, Kyung Hee University, Seoul, Republic of Korea
- Department of Anatomy and Neurobiology, College of Medicine, Kyung Hee University, Seoul, Republic of Korea;
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14
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Synthesis of human amyloid restricted to liver results in an Alzheimer disease-like neurodegenerative phenotype. PLoS Biol 2021; 19:e3001358. [PMID: 34520451 PMCID: PMC8439475 DOI: 10.1371/journal.pbio.3001358] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 07/08/2021] [Indexed: 02/07/2023] Open
Abstract
Several lines of study suggest that peripheral metabolism of amyloid beta (Aß) is associated with risk for Alzheimer disease (AD). In blood, greater than 90% of Aß is complexed as an apolipoprotein, raising the possibility of a lipoprotein-mediated axis for AD risk. In this study, we report that genetic modification of C57BL/6J mice engineered to synthesise human Aß only in liver (hepatocyte-specific human amyloid (HSHA) strain) has marked neurodegeneration concomitant with capillary dysfunction, parenchymal extravasation of lipoprotein-Aß, and neurovascular inflammation. Moreover, the HSHA mice showed impaired performance in the passive avoidance test, suggesting impairment in hippocampal-dependent learning. Transmission electron microscopy shows marked neurovascular disruption in HSHA mice. This study provides causal evidence of a lipoprotein-Aß /capillary axis for onset and progression of a neurodegenerative process. It has been suggested that peripheral metabolism of amyloid-beta is associated with risk for Alzheimer’s disease. This study reveals that the expression of human amyloid exclusively in the liver induces Alzheimer’s disease-like pathologies in mice, potentially indicating a completely novel pathway of Alzheimer’s disease aetiology and therapies.
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15
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Wei Z, Xu J, Chen L, Hirschler L, Barbier EL, Li T, Wong PC, Lu H. Brain metabolism in tau and amyloid mouse models of Alzheimer's disease: An MRI study. NMR IN BIOMEDICINE 2021; 34:e4568. [PMID: 34050996 PMCID: PMC9574887 DOI: 10.1002/nbm.4568] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 05/17/2021] [Accepted: 05/20/2021] [Indexed: 06/12/2023]
Abstract
Alzheimer's disease (AD) is the leading cause of cognitive impairment and dementia in elderly individuals. According to the current biomarker framework for "unbiased descriptive classification", biomarkers of neurodegeneration, "N", constitute a critical component in the tri-category "A/T/N" system. Current biomarkers of neurodegeneration suffer from potential drawbacks such as requiring invasive lumbar puncture, involving ionizing radiation, or representing a late, irreversible marker. Recent human studies have suggested that reduced brain oxygen metabolism may be a new functional marker of neurodegeneration in AD, but the heterogeneity and the presence of mixed pathology in human patients did not allow a full understanding of the role of oxygen extraction and metabolism in AD. In this report, global brain oxygen metabolism and related physiological parameters were studied in two AD mouse models with relatively pure pathology, using advanced MRI techniques including T2 -relaxation-under-spin-tagging (TRUST) and phase contrast (PC) MRI. Additionally, regional cerebral blood flow (CBF) was determined with pseudocontinuous arterial spin labeling. Reduced global oxygen extraction fraction (by -18.7%, p = 0.008), unit-mass cerebral metabolic rate of oxygen (CMRO2 ) (by -17.4%, p = 0.04) and total CMRO2 (by -30.8%, p < 0.001) were observed in Tau4RΔK mice-referred to as the tau AD model-which manifested pronounced neurodegeneration, as measured by diminished brain volume (by -15.2%, p < 0.001). Global and regional CBF in these mice were not different from those of wild-type mice (p > 0.05), suggesting normal vascular function. By contrast, in B6;SJL-Tg [APPSWE]2576Kha (APP) mice-referred to as the amyloid AD model-no brain volume reduction, as well as relatively intact brain oxygen extraction and metabolism, were found (p > 0.05). Consistent with the imaging data, behavioral measures of walking distance were impaired in Tau4RΔK mice (p = 0.004), but not in APP mice (p = 0.88). Collectively, these findings support the hypothesis that noninvasive MRI measurement of brain oxygen metabolism may be a promising biomarker of neurodegeneration in AD.
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Affiliation(s)
- Zhiliang Wei
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Jiadi Xu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
| | - Lin Chen
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
- Department of Electronic Science, Fujian Provincial Key Laboratory of Plasma and Magnetic Resonance, Xiamen University, Xiamen, Fujian, China
| | - Lydiane Hirschler
- Université Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
- C.J. Gorter Center for High Field MRI, Department of Radiology, Leiden University Medical Center, Leiden, The Netherlands
| | - Emmanuel L. Barbier
- Université Grenoble Alpes, Inserm, U1216, Grenoble Institut Neurosciences, Grenoble, France
| | - Tong Li
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Philip C. Wong
- Department of Pathology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
| | - Hanzhang Lu
- Russell H. Morgan Department of Radiology and Radiological Science, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
- F. M. Kirby Research Center for Functional Brain Imaging, Kennedy Krieger Research Institute, Baltimore, Maryland, USA
- Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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16
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Arezoumandan S, Cai X, Kalkarni P, Davis SA, Wilson K, Ferris CF, Cairns NJ, Gitcho MA. Hippocampal neurobiology and function in an aged mouse model of TDP-43 proteinopathy in an APP/PSEN1 background. Neurosci Lett 2021; 758:136010. [PMID: 34090937 DOI: 10.1016/j.neulet.2021.136010] [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: 01/19/2021] [Revised: 05/18/2021] [Accepted: 05/28/2021] [Indexed: 10/21/2022]
Abstract
Aging is a major risk factor for Alzheimer's disease (AD), the most common cause of dementia worldwide. TDP-43 proteinopathy is reported to be associated with AD pathology is almost 50% of cases. Our exploratory study examined near end-stage (28 months old) mice selectively driving expression of human TDP-43 in the hippocampus and cortex in an APP/PSEN1 background. We hypothesized that hippocampal neuropathology caused by β-amyloidosis with TDP-43 proteinopathy induced in this model, resembling the pathology seen in AD cases, manifest with changes in resting state functional connectivity. In vivo magnetic resonance imaging and post-mortem histology were performed on four genotypes: wild type, APP/PSEN1, Camk2a/TDP-43, and Camk2a/TDP-43/APP/PSEN1. Our results revealed loss of functional coupling in hippocampus and amygdala that was associated with severe neuronal loss in dentate gyrus of Camk2a/TDP-43/APP/PSEN1 mice compared to APP/PSEN1 and wild type mice. The loss of cells was accompanied by high background of β-amyloid plaques with sparse phosphorylated TDP-43 pathology. The survival rate was also reduced in Camk2a/TDP-43/APP/PSEN1 mice compared to other groups. This end-of-life study provides exploratory data to reach a better understanding of the role of TDP-43 hippocampal neuropathology in diseases with co-pathologies of TDP-43 proteinopathy and β-amyloidosis such as AD and limbic predominant age-related TDP-43 encephalopathy (LATE).
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Affiliation(s)
- Sanaz Arezoumandan
- Department of Biological Sciences, Delaware State University, Dover, DE, USA; Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, USA
| | - Xuezhu Cai
- Departments of Psychology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA; Center for Translational NeuroImaging, Northeastern University, Boston, MA, USA
| | - Praveen Kalkarni
- Departments of Psychology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA; Center for Translational NeuroImaging, Northeastern University, Boston, MA, USA
| | - Stephani A Davis
- Department of Biological Sciences, Delaware State University, Dover, DE, USA; Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, USA
| | - Katherine Wilson
- Department of Biological Sciences, Delaware State University, Dover, DE, USA; Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, USA
| | - Craig F Ferris
- Departments of Psychology and Pharmaceutical Sciences, Northeastern University, Boston, MA, USA; Center for Translational NeuroImaging, Northeastern University, Boston, MA, USA
| | - Nigel J Cairns
- College of Medicine and Health, University of Exeter, Exeter, UK
| | - Michael A Gitcho
- Department of Biological Sciences, Delaware State University, Dover, DE, USA; Delaware Center for Neuroscience Research, Delaware State University, Dover, DE, USA.
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17
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McQuail JA, Dunn AR, Stern Y, Barnes CA, Kempermann G, Rapp PR, Kaczorowski CC, Foster TC. Cognitive Reserve in Model Systems for Mechanistic Discovery: The Importance of Longitudinal Studies. Front Aging Neurosci 2021; 12:607685. [PMID: 33551788 PMCID: PMC7859530 DOI: 10.3389/fnagi.2020.607685] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Accepted: 12/30/2020] [Indexed: 12/14/2022] Open
Abstract
The goal of this review article is to provide a resource for longitudinal studies, using animal models, directed at understanding and modifying the relationship between cognition and brain structure and function throughout life. We propose that forthcoming longitudinal studies will build upon a wealth of knowledge gleaned from prior cross-sectional designs to identify early predictors of variability in cognitive function during aging, and characterize fundamental neurobiological mechanisms that underlie the vulnerability to, and the trajectory of, cognitive decline. Finally, we present examples of biological measures that may differentiate mechanisms of the cognitive reserve at the molecular, cellular, and network level.
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Affiliation(s)
- Joseph A. McQuail
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina School of Medicine, Columbia, SC, United States
| | - Amy R. Dunn
- The Jackson Laboratory, Bar Harbor, ME, United States
| | - Yaakov Stern
- Cognitive Neuroscience Division, Department of Neurology, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, United States
| | - Carol A. Barnes
- Departments of Psychology and Neuroscience, University of Arizona, Tucson, AZ, United States
- Evelyn F. McKnight Brain Institute, University of Arizona, Tucson, AZ, United States
| | - Gerd Kempermann
- CRTD—Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
- German Center for Neurodegenerative Diseases (DZNE), Helmholtz Association of German Research Centers (HZ), Dresden, Germany
| | - Peter R. Rapp
- Laboratory of Behavioral Neuroscience, Neurocognitive Aging Section, National Institute on Aging, Baltimore, MD, United States
| | | | - Thomas C. Foster
- Department of Neuroscience, McKnight Brain Institute, University of Florida, Gainesville, FL, United States
- Genetics and Genomics Program, University of Florida, Gainesville, FL, United States
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18
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Hill LK, Hoang DM, Chiriboga LA, Wisniewski T, Sadowski MJ, Wadghiri YZ. Detection of Cerebrovascular Loss in the Normal Aging C57BL/6 Mouse Brain Using in vivo Contrast-Enhanced Magnetic Resonance Angiography. Front Aging Neurosci 2020; 12:585218. [PMID: 33192479 PMCID: PMC7606987 DOI: 10.3389/fnagi.2020.585218] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Accepted: 09/11/2020] [Indexed: 12/28/2022] Open
Abstract
Microvascular rarefaction, or the decrease in vascular density, has been described in the cerebrovasculature of aging humans, rats, and, more recently, mice in the presence and absence of age-dependent diseases. Given the wide use of mice in modeling age-dependent human diseases of the cerebrovasculature, visualization, and quantification of the global murine cerebrovasculature is necessary for establishing the baseline changes that occur with aging. To provide in vivo whole-brain imaging of the cerebrovasculature in aging C57BL/6 mice longitudinally, contrast-enhanced magnetic resonance angiography (CE-MRA) was employed using a house-made gadolinium-bearing micellar blood pool agent. Enhancement in the vascular space permitted quantification of the detectable, or apparent, cerebral blood volume (aCBV), which was analyzed over 2 years of aging and compared to histological analysis of the cerebrovascular density. A significant loss in the aCBV was detected by CE-MRA over the aging period. Histological analysis via vessel-probing immunohistochemistry confirmed a significant loss in the cerebrovascular density over the same 2-year aging period, validating the CE-MRA findings. While these techniques use widely different methods of assessment and spatial resolutions, their comparable findings in detected vascular loss corroborate the growing body of literature describing vascular rarefaction aging. These findings suggest that such age-dependent changes can contribute to cerebrovascular and neurodegenerative diseases, which are modeled using wild-type and transgenic laboratory rodents.
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Affiliation(s)
- Lindsay K. Hill
- Department of Chemical and Biomolecular Engineering, NYU Tandon School of Engineering, Brooklyn, NY, United States
- Department of Radiology, Center for Advanced Imaging Innovation and Research (CAI2R), NYU Grossman School of Medicine, New York, NY, United States
- Department of Radiology, Bernard and Irene Schwartz Center for Biomedical Imaging, NYU Grossman School of Medicine, New York, NY, United States
- Department of Biomedical Engineering, SUNY Downstate Medical Center, Brooklyn, NY, United States
| | - Dung Minh Hoang
- Department of Radiology, Center for Advanced Imaging Innovation and Research (CAI2R), NYU Grossman School of Medicine, New York, NY, United States
- Department of Radiology, Bernard and Irene Schwartz Center for Biomedical Imaging, NYU Grossman School of Medicine, New York, NY, United States
| | - Luis A. Chiriboga
- Department of Pathology, NYU Grossman School of Medicine, New York, NY, United States
| | - Thomas Wisniewski
- Department of Pathology, NYU Grossman School of Medicine, New York, NY, United States
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY, United States
| | - Martin J. Sadowski
- Department of Neurology, NYU Grossman School of Medicine, New York, NY, United States
- Department of Psychiatry, NYU Grossman School of Medicine, New York, NY, United States
- Department of Biochemistry and Molecular Pharmacology, NYU Grossman School of Medicine, New York, NY, United States
| | - Youssef Z. Wadghiri
- Department of Radiology, Center for Advanced Imaging Innovation and Research (CAI2R), NYU Grossman School of Medicine, New York, NY, United States
- Department of Radiology, Bernard and Irene Schwartz Center for Biomedical Imaging, NYU Grossman School of Medicine, New York, NY, United States
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19
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Gui Y, Thomas MH, Garcia P, Karout M, Halder R, Michelucci A, Kollmus H, Zhou C, Melmed S, Schughart K, Balling R, Mittelbronn M, Nadeau JH, Williams RW, Sauter T, Buttini M, Sinkkonen L. Pituitary Tumor Transforming Gene 1 Orchestrates Gene Regulatory Variation in Mouse Ventral Midbrain During Aging. Front Genet 2020; 11:566734. [PMID: 33173537 PMCID: PMC7538689 DOI: 10.3389/fgene.2020.566734] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2020] [Accepted: 08/27/2020] [Indexed: 01/07/2023] Open
Abstract
Dopaminergic neurons in the midbrain are of particular interest due to their role in diseases such as Parkinson’s disease and schizophrenia. Genetic variation between individuals can affect the integrity and function of dopaminergic neurons but the DNA variants and molecular cascades modulating dopaminergic neurons and other cells types of ventral midbrain remain poorly defined. Three genetically diverse inbred mouse strains – C57BL/6J, A/J, and DBA/2J – differ significantly in their genomes (∼7 million variants), motor and cognitive behavior, and susceptibility to neurotoxins. To further dissect the underlying molecular networks responsible for these variable phenotypes, we generated RNA-seq and ChIP-seq data from ventral midbrains of the 3 mouse strains. We defined 1000–1200 transcripts that are differentially expressed among them. These widespread differences may be due to altered activity or expression of upstream transcription factors. Interestingly, transcription factors were significantly underrepresented among the differentially expressed genes, and only one transcription factor, Pttg1, showed significant differences between all three strains. The changes in Pttg1 expression were accompanied by consistent alterations in histone H3 lysine 4 trimethylation at Pttg1 transcription start site. The ventral midbrain transcriptome of 3-month-old C57BL/6J congenic Pttg1–/– mutants was only modestly altered, but shifted toward that of A/J and DBA/2J in 9-month-old mice. Principle component analysis (PCA) identified the genes underlying the transcriptome shift and deconvolution of these bulk RNA-seq changes using midbrain single cell RNA-seq data suggested that the changes were occurring in several different cell types, including neurons, oligodendrocytes, and astrocytes. Taken together, our results show that Pttg1 contributes to gene regulatory variation between mouse strains and influences mouse midbrain transcriptome during aging.
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Affiliation(s)
- Yujuan Gui
- Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
| | - Mélanie H Thomas
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Pierre Garcia
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg.,National Center of Pathology, Laboratoire National de Santé, Dudelange, Luxembourg.,Luxembourg Centre of Neuropathology, Dudelange, Luxembourg
| | - Mona Karout
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Rashi Halder
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Alessandro Michelucci
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg.,Department of Oncology, Luxembourg Institute of Health, Luxembourg City, Luxembourg
| | - Heike Kollmus
- Department of Infection Genetics, Helmholtz Centre for Infection Research, Braunschweig, Germany
| | - Cuiqi Zhou
- Cedars Sinai Medical Centre, Los Angeles, CA, United States
| | - Shlomo Melmed
- Cedars Sinai Medical Centre, Los Angeles, CA, United States
| | - Klaus Schughart
- Department of Infection Genetics, Helmholtz Centre for Infection Research, Braunschweig, Germany.,Department of Infection Genetics, University of Veterinary Medicine Hannover, Hanover, Germany.,Department of Microbiology, Immunology and Biochemistry, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Rudi Balling
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Michel Mittelbronn
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg.,National Center of Pathology, Laboratoire National de Santé, Dudelange, Luxembourg.,Luxembourg Centre of Neuropathology, Dudelange, Luxembourg.,Department of Oncology, Luxembourg Institute of Health, Luxembourg City, Luxembourg
| | - Joseph H Nadeau
- Pacific Northwest Research Institute, Seattle, WA, United States.,Maine Medical Center Research Institute, Scarborough, ME, United States
| | - Robert W Williams
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, Memphis, TN, United States
| | - Thomas Sauter
- Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
| | - Manuel Buttini
- Luxembourg Centre for Systems Biomedicine, University of Luxembourg, Belvaux, Luxembourg
| | - Lasse Sinkkonen
- Department of Life Sciences and Medicine, University of Luxembourg, Belvaux, Luxembourg
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20
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Taylor EN, Huang N, Wisco J, Wang Y, Morgan KG, Hamilton JA. The brains of aged mice are characterized by altered tissue diffusion properties and cerebral microbleeds. J Transl Med 2020; 18:277. [PMID: 32641073 PMCID: PMC7346388 DOI: 10.1186/s12967-020-02441-6] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Accepted: 06/29/2020] [Indexed: 12/29/2022] Open
Abstract
Background Brain aging is a major risk factor in the progression of cognitive diseases including Alzheimer’s disease (AD) and vascular dementia. We investigated a mouse model of brain aging up to 24 months old (mo). Methods A high field (11.7T) MRI protocol was developed to characterize specific features of brain aging including the presence of cerebral microbleeds (CMBs), morphology of grey and white matter, and tissue diffusion properties. Mice were selected from age categories of either young (3 mo), middle-aged (18 mo), or old (24 mo) and fed normal chow over the duration of the study. Mice were imaged in vivo with multimodal MRI, including conventional T2-weighted (T2W) and T2*-weighted (T2*W) imaging, followed by ex vivo diffusion-weighted imaging (DWI) and T2*W MR-microscopy to enhance the detection of microstructural features. Results Structural changes observed in the mouse brain with aging included reduced cortical grey matter volume and enlargement of the brain ventricles. A remarkable age-related change in the brains was the development of CMBs found starting at 18 mo and increasing in total volume at 24 mo, primarily in the thalamus. CMBs presence was confirmed with high resolution ex vivo MRI and histology. DWI detected further brain tissue changes in the aged mice including reduced fractional anisotropy, increased radial diffusion, increased mean diffusion, and changes in the white matter fibers visualized by color-coded tractography, including around a large cortical CMB. Conclusions The mouse is a valuable model of age-related vascular contributions to cognitive impairment and dementia (VCID). In composite, these methods and results reveal brain aging in older mice as a multifactorial process including CMBs and tissue diffusion alterations that can be well characterized by high field MRI.
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Affiliation(s)
- Erik N Taylor
- Department of Radiology, University of New Mexico, Albuquerque, NM, USA. .,Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA, USA. .,Department of Biomedical Engineering, Boston University, Boston, MA, USA.
| | - Nasi Huang
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA, USA.,Department of Biomedical Engineering, Boston University, Boston, MA, USA
| | - Jonathan Wisco
- Department of Anatomy & Neurobiology, Boston University School of Medicine, Boston, MA, USA
| | - Yandan Wang
- Department of Health Sciences, Boston University, Boston, MA, USA
| | | | - James A Hamilton
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA, USA. .,Department of Biomedical Engineering, Boston University, Boston, MA, USA.
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21
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Cognitive impairment appears progressive in the mdx mouse. Neuromuscul Disord 2020; 30:368-388. [PMID: 32360405 PMCID: PMC7306157 DOI: 10.1016/j.nmd.2020.02.018] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 02/24/2020] [Accepted: 02/25/2020] [Indexed: 11/22/2022]
Abstract
Duchenne muscular dystrophy (DMD) is an X-linked recessive muscle wasting disease caused by mutations in the DMD gene, which encodes the large cytoskeletal protein dystrophin. Approximately one-third of DMD patient's exhibit cognitive problems yet it is unknown if cognitive impairments worsen with age. The mdx mouse model is deficient in dystrophin demonstrates cognitive abnormalities, but no studies have investigated this longitudinally. We assessed the consequences of dystrophin deficiency on brain morphology and cognition in male mdx mice. We utilised non-invasive methods to monitor CNS pathology with an aim to identify changes longitudinally (between 4 and 18 months old) which could be used as outcome measures. MRI identified a total brain volume (TBV) increase in control mice with ageing (p < 0.05); but the mdx mice TBV increased significantly more (p < 0.01). Voxel-based morphometry (VBM) identified decreases in grey matter volume, particularly in the hippocampus of the mdx brain, most noticeable from 12 months onwards, as were enlarged lateral ventricles in mdx mice. The caudate putamen of older mdx mice showed increases in T2- relaxometry which may be considered as evidence of increased water content. Hippocampal spatial learning and memory was decreased in mdx mice, particularly long-term memory, which progressively worsened with age. The novel object recognition (NOR) task highlighted elevated anxiety-related behaviour in older mdx mice. Our studies suggest that dystrophin deficiency causes a progressive cognitive impairment in mice (compared to ageing control mice), becoming evident at late disease stages, and may explain why progressive CNS symptoms are not obvious in DMD patients.
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22
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Cerebrospinal fluid progranulin is associated with increased cortical thickness in early stages of Alzheimer's disease. Neurobiol Aging 2019; 88:61-70. [PMID: 31980280 DOI: 10.1016/j.neurobiolaging.2019.12.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 12/11/2019] [Accepted: 12/14/2019] [Indexed: 11/22/2022]
Abstract
Progranulin plays an important role in neuroinflammation in Alzheimer's disease (AD) pathophysiology, being upregulated by activated microglia. This study assessed whether cerebrospinal fluid levels of progranulin correlated with structural neuroimaging measures and cognition in 122 cognitively normal individuals, 81 mild cognitive impairment, and 70 AD patients from the Alzheimer's Disease Neuroimaging Initiative. Cognitively normal subjects were classified into 3 groups using the AT(N) system, whereas all mild cognitive impairment and AD patients were A+/TN+. Correlations between progranulin with neuroanatomical measures and cognitive decline were performed within each group. Progranulin was associated with cortical thickening in parietal, occipital, and frontal regions in cognitively normal individuals with amyloid pathology. These subjects also showed cortical thickening compared with A-/TN- subjects, an effect that was partially mediated by progranulin. In addition, higher progranulin correlated with longitudinal cognitive decline. The association between progranulin and cortical thickening, together with regional "brain swelling" in A+/TN- subjects, suggests progranulin contributes to the neuroinflammatory structural changes in preclinical AD.
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23
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Spampanato J, Gibson A, Dudek FE. The antihelminthic moxidectin enhances tonic GABA currents in rodent hippocampal pyramidal neurons. J Neurophysiol 2018; 119:1693-1698. [PMID: 29364072 DOI: 10.1152/jn.00587.2017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Macrocyclic lactones (MLs) are commonly used treatments for parasitic worm and insect infections in humans, livestock, and companion animals. MLs target the invertebrate glutamate-activated chloride channel that is not present in vertebrates. MLs are not entirely inert in vertebrates, though; they have been reported to have activity in heterologous expression systems consisting of ligand-gated ion channels that are present in the mammalian central nervous system (CNS). However, these compounds are typically not able to reach significant concentrations in the CNS because of the activity of the blood-brain barrier P-glycoprotein extrusion system. Despite this, these compounds are able to reach low levels in the CNS that may be useful in the design of novel "designer" ligand-receptor systems that can be used to directly investigate neuronal control of behavior in mammals and have potential for use in treating human neurological diseases. To determine whether MLs might affect neurons in intact brains, we investigated the activity of the ML moxidectin (MOX) at native GABA receptors. Specifically, we recorded tonic and phasic miniature inhibitory postsynaptic currents (mIPSCs) in ex vivo brain slices. Our data show that MOX potentiated tonic GABA currents in a dose-dependent manner but had no concomitant effects on phasic GABA currents (i.e., MOX had no effect on the amplitude, frequency, or decay kinetics of mIPSCs). These studies indicate that behavioral experiments that implement a ML-based novel ligand-receptor system should take care to control for potential effects of the ML on native tonic GABA receptors. NEW & NOTEWORTHY We have identified a novel mechanism of action in the mammalian central nervous system for the antihelminthic moxidectin, commonly prescribed to animals worldwide and currently being evaluated for use in humans. Specifically, moxidectin applied to rodent brain slices selectively enhanced the tonic GABA conductance of hippocampal pyramidal neurons.
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Affiliation(s)
- Jay Spampanato
- Department of Neurosurgery, University of Utah School of Medicine , Salt Lake City, Utah
| | - Anne Gibson
- Department of Neurosurgery, University of Utah School of Medicine , Salt Lake City, Utah
| | - F Edward Dudek
- Department of Neurosurgery, University of Utah School of Medicine , Salt Lake City, Utah
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Sahara N, Shimojo M, Ono M, Takuwa H, Febo M, Higuchi M, Suhara T. In Vivo Tau Imaging for a Diagnostic Platform of Tauopathy Using the rTg4510 Mouse Line. Front Neurol 2017; 8:663. [PMID: 29375461 PMCID: PMC5770623 DOI: 10.3389/fneur.2017.00663] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Accepted: 11/23/2017] [Indexed: 12/23/2022] Open
Abstract
Association of tau deposition with neurodegeneration in Alzheimer's disease (AD) and related tau-positive neurological disorders collectively referred to as tauopathies indicates contribution of tau aggregates to neurotoxicity. The discovery of tau gene mutations in FTDP-17-tau kindreds has provided unequivocal evidence that tau abnormalities alone can induce neurodegenerative disorders. Therefore, visualization of tau accumulation would offer a reliable, objective index to aid in the diagnosis of tauopathy and to assess the disease progression. Positron emission tomography (PET) imaging of tau lesions is currently available using several tau PET ligands. Because most tau PET ligands have the property of an extrinsic fluorescent dye, these ligands are considered to be useful for both PET and fluorescence imaging. In addition, small-animal magnetic resonance imaging (MRI) is available for both structural and functional imaging. Using these advanced imaging techniques, in vivo studies on a mouse model of tauopathy will provide significant insight into the translational research of neurodegenerative diseases. In this review, we will discuss the utilities of PET, MRI, and fluorescence imaging for evaluating the disease progression of tauopathy.
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Affiliation(s)
- Naruhiko Sahara
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Masafumi Shimojo
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Maiko Ono
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Hiroyuki Takuwa
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Marcelo Febo
- Department of Psychiatry and Neuroscience, University of Florida College of Medicine, Gainesville, FL, United States
| | - Makoto Higuchi
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
| | - Tetsuya Suhara
- Department of Functional Brain Imaging Research, National Institute of Radiological Sciences, National Institutes for Quantum and Radiological Science and Technology, Chiba, Japan
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25
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Mahajan D, Votruba M. Can the retina be used to diagnose and plot the progression of Alzheimer's disease? Acta Ophthalmol 2017; 95:768-777. [PMID: 29220126 DOI: 10.1111/aos.13472] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2016] [Accepted: 04/03/2017] [Indexed: 12/25/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease and the most common cause of senile dementia. It impairs the quality of life of a person and their family, posing a serious economic and social threat in developed countries. The fact that the diagnosis can only be definitively made post-mortem, or when the disease is fairly advanced, presents a serious problem if novel therapeutic interventions are to be devised and used early in the course of the disease. There is therefore a pressing need for more sensitive and specific diagnostic tests with which we can detect AD in the preclinical stage. The tau proteins and beta-amyloid proteins start to accumulate 20 years before the symptoms begin to manifest. Detecting them in the preclinical stage would be a potential breakthrough in the management of AD. A high degree of clinical suspicion is needed to correlate problems in cognition with the changes in the eye, particularly the retina, pupil and ocular movements, so that the disease can be detected early and managed in the prodromal phase. In this systematic review, we ask the question whether the retina can be used to make a specific and early diagnosis of AD.
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Affiliation(s)
- Deepti Mahajan
- School of Optometry and Vision Sciences; Cardiff University; Cardiff UK
| | - Marcela Votruba
- School of Optometry and Vision Sciences; Cardiff University; Cardiff UK
- University Hospital of Wales; Cardiff UK
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26
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Casas R, Muthusamy S, Wakim PG, Sinharay S, Lentz MR, Reid WC, Hammoud DA. MR brain volumetric measurements are predictive of neurobehavioral impairment in the HIV-1 transgenic rat. NEUROIMAGE-CLINICAL 2017; 17:659-666. [PMID: 29204344 PMCID: PMC5705794 DOI: 10.1016/j.nicl.2017.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Revised: 09/11/2017] [Accepted: 11/18/2017] [Indexed: 01/18/2023]
Abstract
Introduction HIV infection is known to be associated with brain volume loss, even in optimally treated patients. In this study, we assessed whether dynamic brain volume changes over time are predictive of neurobehavorial performance in the HIV-1 transgenic (Tg) rat, a model of treated HIV-positive patients. Materials and methods Cross-sectional brain MRI imaging was first performed comparing Tg and wild type (WT) rats at 3 and 19 months of age. Longitudinal MRI and neurobehavioral testing of another group of Tg and WT rats was then performed from 5 to 23 weeks of age. Whole brain and subregional image segmentation was used to assess the rate of brain growth over time. We used repeated-measures mixed models to assess differences in brain volumes and to establish how predictive the volume differences are of specific neurobehavioral deficits. Results Cross-sectional imaging showed smaller whole brain volumes in Tg compared to WT rats at 3 and at 19 months of age. Longitudinally, Tg brain volumes were smaller than age-matched WT rats at all time points, starting as early as 5 weeks of age. The Tg striatal growth rate delay between 5 and 9 weeks of age was greater than that of the whole brain. Striatal volume in combination with genotype was the most predictive of rota-rod scores and in combination with genotype and age was the most predictive of total exploratory activity scores in the Tg rats. Conclusion The disproportionately delayed striatal growth compared to whole brain between 5 and 9 weeks of age and the role of striatal volume in predicting neurobehavioral deficits suggest an important role of the dopaminergic system in HIV associated neuropathology. This might explain problems with motor coordination and executive decisions in this animal model. Smaller brain and subregional volumes and neurobehavioral deficits were seen as early as 5 weeks of age, suggesting an early brain insult in the Tg rat. Neuroprotective therapy testing in this model should thus target this early stage of development, before brain damage becomes irreversible. HIV infection is known to be associated with brain volume loss. HIV transgenic rats showed smaller brain volumes than wild type rats. Tg rats showed disproportionate loss of volume in the striatum compared to brain. Tg striatal volume loss along with genotype/age predict neurobehavioral deficits.
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Affiliation(s)
- Rafael Casas
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Siva Muthusamy
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Paul G Wakim
- Biostatistics and Clinical Epidemiology Service, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Sanhita Sinharay
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Margaret R Lentz
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - William C Reid
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States
| | - Dima A Hammoud
- Center for Infectious Disease Imaging (CIDI), Radiology and Imaging Sciences, Clinical Center, National Institutes of Health (NIH), Bethesda, MD, United States.
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27
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Watson C, Janke AL, Hamalainen C, Bagheri SM, Paxinos G, Reutens DC, Ullmann JFP. An ontologically consistent MRI-based atlas of the mouse diencephalon. Neuroimage 2017; 157:275-287. [PMID: 28578128 DOI: 10.1016/j.neuroimage.2017.05.057] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 05/01/2017] [Accepted: 05/27/2017] [Indexed: 11/19/2022] Open
Abstract
In topological terms, the diencephalon lies between the hypothalamus and the midbrain. It is made up of three segments, prosomere 1 (pretectum), prosomere 2 (thalamus), and prosomere 3 (the prethalamus). A number of MRI-based atlases of different parts of the mouse brain have already been published, but none of them displays the segments the diencephalon and their component nuclei. In this study we present a new volumetric atlas identifying 89 structures in the diencephalon of the male C57BL/6J 12 week mouse. This atlas is based on an average of MR scans of 18 mouse brains imaged with a 16.4T scanner. This atlas is available for download at www.imaging.org.au/AMBMC. Additionally, we have created an FSL package to enable nonlinear registration of novel data sets to the AMBMC model and subsequent automatic segmentation.
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Affiliation(s)
- Charles Watson
- The Australian Mouse Brain Mapping Consortium, The University of Queensland, Brisbane, Australia; Health Sciences, Curtin University, Perth, Western Australia, Australia; Neuroscience Research Australia and The University of New South Wales, Sydney, Australia.
| | - Andrew L Janke
- The Australian Mouse Brain Mapping Consortium, The University of Queensland, Brisbane, Australia; Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - Carlo Hamalainen
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - Shahrzad M Bagheri
- Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - George Paxinos
- Neuroscience Research Australia and The University of New South Wales, Sydney, Australia
| | - David C Reutens
- The Australian Mouse Brain Mapping Consortium, The University of Queensland, Brisbane, Australia; Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia
| | - Jeremy F P Ullmann
- The Australian Mouse Brain Mapping Consortium, The University of Queensland, Brisbane, Australia; Centre for Advanced Imaging, The University of Queensland, Brisbane, Australia; Department of Neurology, Boston Children's Hospital, Boston, MA, USA
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28
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Franco Bocanegra DK, Nicoll JAR, Boche D. Innate immunity in Alzheimer's disease: the relevance of animal models? J Neural Transm (Vienna) 2017; 125:827-846. [PMID: 28516241 PMCID: PMC5911273 DOI: 10.1007/s00702-017-1729-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Accepted: 04/27/2017] [Indexed: 12/12/2022]
Abstract
The mouse is one of the organisms most widely used as an animal model in biomedical research, due to the particular ease with which it can be handled and reproduced in laboratory. As a member of the mammalian class, mice share with humans many features regarding metabolic pathways, cell morphology and anatomy. However, important biological differences between mice and humans exist and must be taken into consideration when interpreting research results, to properly translate evidence from experimental studies into information that can be useful for human disease prevention and/or treatment. With respect to Alzheimer’s disease (AD), much of the experimental information currently known about this disease has been gathered from studies using mainly mice as models. Therefore, it is notably important to fully characterise the differences between mice and humans regarding important aspects of the disease. It is now widely known that inflammation plays an important role in the development of AD, a role that is not only a response to the surrounding pathological environment, but rather seems to be strongly implicated in the aetiology of the disease as indicated by the genetic studies. This review highlights relevant differences in inflammation and in microglia, the innate immune cell of the brain, between mice and humans regarding genetics and morphology in normal ageing, and the relationship of microglia with AD-like pathology, the inflammatory profile, and cognition. We conclude that some noteworthy differences exist between mice and humans regarding microglial characteristics, in distribution, gene expression, and states of activation. This may have repercussions in the way that transgenic mice respond to, and influence, the AD-like pathology. However, despite these differences, human and mouse microglia also show similarities in morphology and behaviour, such that the mouse is a suitable model for studying the role of microglia, as long as these differences are taken into consideration when delineating new strategies to approach the study of neurodegenerative diseases.
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Affiliation(s)
- Diana K Franco Bocanegra
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Mailpoint 806, Southampton, SO16 6YD, UK
| | - James A R Nicoll
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Mailpoint 806, Southampton, SO16 6YD, UK.,Department of Cellular Pathology, University Hospital Southampton NHS Foundation Trust, Southampton, Southampton, SO16 6YD, UK
| | - Delphine Boche
- Clinical Neurosciences, Clinical and Experimental Sciences Academic Unit, Faculty of Medicine, University of Southampton, Southampton General Hospital, Mailpoint 806, Southampton, SO16 6YD, UK.
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29
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Bettio LEB, Rajendran L, Gil-Mohapel J. The effects of aging in the hippocampus and cognitive decline. Neurosci Biobehav Rev 2017; 79:66-86. [PMID: 28476525 DOI: 10.1016/j.neubiorev.2017.04.030] [Citation(s) in RCA: 346] [Impact Index Per Article: 49.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 03/15/2017] [Accepted: 04/10/2017] [Indexed: 02/06/2023]
Abstract
Aging is a natural process that is associated with cognitive decline as well as functional and social impairments. One structure of particular interest when considering aging and cognitive decline is the hippocampus, a brain region known to play an important role in learning and memory consolidation as well as in affective behaviours and mood regulation, and where both functional and structural plasticity (e.g., neurogenesis) occur well into adulthood. Neurobiological alterations seen in the aging hippocampus including increased oxidative stress and neuroinflammation, altered intracellular signalling and gene expression, as well as reduced neurogenesis and synaptic plasticity, are thought to be associated with age-related cognitive decline. Non-invasive strategies such as caloric restriction, physical exercise, and environmental enrichment have been shown to counteract many of the age-induced alterations in hippocampal signalling, structure, and function. Thus, such approaches may have therapeutic value in counteracting the deleterious effects of aging and protecting the brain against age-associated neurodegenerative processes.
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Affiliation(s)
- Luis E B Bettio
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Luckshi Rajendran
- Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada
| | - Joana Gil-Mohapel
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada; UBC Island Medical program, University of Victoria, Victoria, BC, Canada.
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30
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Reichel JM, Bedenk BT, Czisch M, Wotjak CT. Age-related cognitive decline coincides with accelerated volume loss of the dorsal but not ventral hippocampus in mice. Hippocampus 2016; 27:28-35. [PMID: 27699923 DOI: 10.1002/hipo.22668] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/30/2016] [Indexed: 12/11/2022]
Abstract
Even in the absence of neurodegenerative diseases, progressing age often coincides with cognitive decline and morphological changes. However, longitudinal studies that directly link these two processes are missing. In this proof-of-concept study we therefore performed repeated within-subject testing of healthy male R26R mice in a spatial learning task in combination with manganese-enhanced volumetric MRI analyses at the ages of 8, 16, and 24 months. We grouped the mice into good and poor performers (n = 6, each), based on their spatial learning abilities at the age of 24 months. Using this stratification, we failed to detect a priori volume differences, but observed a significant decrease in total hippocampal volume over time for both groups. Interestingly, this volume decrease was specific for the dorsal hippocampus and significantly accelerated in poor performers between 16 and 24 months of age. This is the first time that individual changes in hippocampal volume were traced alongside cognitive performance within the same subjects over 1½ years. Our study points to a causal link between volume loss of the dorsal hippocampus and cognitive impairments. In addition, it suggests accelerated degenerative processes rather than a priori volume differences as determining trajectories of age-related cognitive decline. Despite the relatively small sample sizes, the strong behavioral and moderate morphological alterations demonstrate the general feasibility of longitudinal studies of age-related decline in cognition and hippocampus integrity. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- J M Reichel
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
| | - B T Bedenk
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany.,Core Unit Neuroimaging, Max Planck Institute of Psychiatry, Munich, Germany
| | - M Czisch
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany.,Core Unit Neuroimaging, Max Planck Institute of Psychiatry, Munich, Germany
| | - C T Wotjak
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, Munich, Germany
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31
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Longitudinal imaging of the ageing mouse. Mech Ageing Dev 2016; 160:93-116. [PMID: 27530773 DOI: 10.1016/j.mad.2016.08.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Revised: 07/30/2016] [Accepted: 08/04/2016] [Indexed: 12/13/2022]
Abstract
Several non-invasive imaging techniques are used to investigate the effect of pathologies and treatments over time in mouse models. Each preclinical in vivo technique provides longitudinal and quantitative measurements of changes in tissues and organs, which are fundamental for the evaluation of alterations in phenotype due to pathologies, interventions and treatments. However, it is still unclear how these imaging modalities can be used to study ageing with mice models. Almost all age related pathologies in mice such as osteoporosis, arthritis, diabetes, cancer, thrombi, dementia, to name a few, can be imaged in vivo by at least one longitudinal imaging modality. These measurements are the basis for quantification of treatment effects in the development phase of a novel treatment prior to its clinical testing. Furthermore, the non-invasive nature of such investigations allows the assessment of different tissue and organ phenotypes in the same animal and over time, providing the opportunity to study the dysfunction of multiple tissues associated with the ageing process. This review paper aims to provide an overview of the applications of the most commonly used in vivo imaging modalities used in mouse studies: micro-computed-tomography, preclinical magnetic-resonance-imaging, preclinical positron-emission-tomography, preclinical single photon emission computed tomography, ultrasound, intravital microscopy, and whole body optical imaging.
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32
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Long-term dantrolene treatment reduced intraneuronal amyloid in aged Alzheimer triple transgenic mice. Alzheimer Dis Assoc Disord 2016; 29:184-191. [PMID: 25650693 DOI: 10.1097/wad.0000000000000075] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
In this study, we investigated the long-term treatment of dantrolene on amyloid and tau neuropathology, brain volume, and cognitive function in aged triple transgenic Alzheimer (3xTg-AD) mice. Fifteen-month old 3xTg-AD mice and wild-type controls were treated with oral dantrolene (5 mg/kg) or vehicle control twice a week for 6 months. Learning and memory were examined using the Morris Water Maze at 21 and 22 months of age. After the behavioral testing, hippocampal and cortical brain volumes were calculated with magnetic resonance imaging and motor function was evaluated using the rotorod. The amyloid burden and tau neurofibrillary tangles in the hippocampus were determined using immunohistochemistry. We found that dantrolene significantly decreased the intraneuronal amyloid accumulation by as much as 76% compared with its corresponding vehicle control, together with a trend to reduce phosphorylated tau in the hippocampus. No significant differences could be detected in hippocampal or cortical brain volume, motor function or cognition among all experimental groups, indicating that the mice were still presymptomatic for Alzheimer disease. Thus, presymptomatic and long-term dantrolene treatment significantly decreased the intraneuronal amyloid burden in aged 3xTg-AD mice before significant changes in brain volume, or cognition.
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33
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Magisetty O, Dowlathabad MR, Raichurkar KP, Mannar SN. First magenetic resonance imaging studies on aluminium maltolate-treated aged New Zealand rabbits: an Alzheimer's animal model. Psychogeriatrics 2016; 16:263-7. [PMID: 26419490 DOI: 10.1111/psyg.12158] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/17/2012] [Revised: 02/23/2015] [Accepted: 08/12/2015] [Indexed: 11/29/2022]
Abstract
BACKGROUND Alzheimer's disease is a devastative neurodegenerative disorder. To date, there has been no animal model that could unravel the complete disease pathology. Magnetic resonance imaging has played a pivotal role in the quantitative assessment of brain tissue atrophy for a few decades. In particular, temporal lobe atrophy and ventricular dilatation have been found to be sensitive in Alzheimer's disease. METHODS The present study focused on the replication of these crucial pathological events to enable disease progression to be diagnosed at an early stage and stopped through the use of potential therapeutic strategies. RESULT The objective of this study was to show temporal lobe atrophy and ventricular dilatation in aluminium maltolate-treated aged New Zealand rabbit, and our study was able to demonstrate this for the first time. CONCLUSION The present study makes this animal model a substantial one for further molecular level studies and opens up new targets for potential therapeutic strategies.
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Affiliation(s)
- Obulesu Magisetty
- Department of Materials Science, Graduate School of Pure and Applied Sciences, University of Tsukuba, Tsukuba, Ibaraki-305-8573, Japan
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34
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Kärkkäinen E, Lahtinen HM, Närväinen J, Gröhn O, Tanila H. Brain Amyloidosis and BDNF Deficiency Have Opposite Effects on Brain Volumes in AβPP/PS1 Mice Both in vivo and ex vivo. J Alzheimers Dis 2016; 46:929-46. [PMID: 26402627 DOI: 10.3233/jad-150059] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Magnetic resonance imaging (MRI) volumetry is widely used in Alzheimer's disease (AD) research and diagnostics alongside clinical assessment. Yet few MRI volumetry studies have been conducted in AD model mice with mixed results. We performed in vivo and ex vivo MRI and extensive postmortem histological analysis in transgenic mice derived from crossing amyloid plaque producing AβPP/PS1 mice with brain-derived neurotrophic factor (BDNF) +/- mice. This allowed us to compare developmental volumetric changes due to BDNF deficiency with progressive changes due to amyloid accumulation. We found decreased whole brain volume at 3 months and decreased cortical volume at both 3 and 8 months in vivo in BDNF +/- Tg mice but increased whole brain and cortical volumes at 8 months in AβPP/PS1 mice. Consistent with this, the postmortem histological analysis showed decreased brain parenchymal area in BDNF +/- mice but an increase in AβPP/PS1 mice. BDNF gene deficiency did not affect brain amyloid load or astrogliosis, but led to decreased dentate gyrus length, whereas AβPP/PS1 mice had significantly increased amyloid load, astrogliosis, and decreased neurogenesis. Distinct and layer-specific effects were found in the hippocampus of AβPP/PS1 and BDNF +/- mice. In contrast to human AD patients, brain atrophy in amyloid producing mice appears to be masked by volume increase due to amyloid accumulation and especially accompanying astrogliosis. Our results indicate that cortical MRI volumetry can be used to some extent as a proxy to progressive brain amyloidosis in preclinical studies.
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Affiliation(s)
- Elisa Kärkkäinen
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | | | - Johanna Närväinen
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Olli Gröhn
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland
| | - Heikki Tanila
- A.I. Virtanen Institute, University of Eastern Finland, Kuopio, Finland.,Department of Neurology, Kuopio University Hospital, Kuopio, Finland
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35
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Febo M, Foster TC. Preclinical Magnetic Resonance Imaging and Spectroscopy Studies of Memory, Aging, and Cognitive Decline. Front Aging Neurosci 2016; 8:158. [PMID: 27468264 PMCID: PMC4942756 DOI: 10.3389/fnagi.2016.00158] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2016] [Accepted: 06/16/2016] [Indexed: 01/14/2023] Open
Abstract
Neuroimaging provides for non-invasive evaluation of brain structure and activity and has been employed to suggest possible mechanisms for cognitive aging in humans. However, these imaging procedures have limits in terms of defining cellular and molecular mechanisms. In contrast, investigations of cognitive aging in animal models have mostly utilized techniques that have offered insight on synaptic, cellular, genetic, and epigenetic mechanisms affecting memory. Studies employing magnetic resonance imaging and spectroscopy (MRI and MRS, respectively) in animal models have emerged as an integrative set of techniques bridging localized cellular/molecular phenomenon and broader in vivo neural network alterations. MRI methods are remarkably suited to longitudinal tracking of cognitive function over extended periods permitting examination of the trajectory of structural or activity related changes. Combined with molecular and electrophysiological tools to selectively drive activity within specific brain regions, recent studies have begun to unlock the meaning of fMRI signals in terms of the role of neural plasticity and types of neural activity that generate the signals. The techniques provide a unique opportunity to causally determine how memory-relevant synaptic activity is processed and how memories may be distributed or reconsolidated over time. The present review summarizes research employing animal MRI and MRS in the study of brain function, structure, and biochemistry, with a particular focus on age-related cognitive decline.
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Affiliation(s)
- Marcelo Febo
- Department of Psychiatry, William L. and Evelyn F. McKnight Brain Institute, University of Florida Gainesville, FL, USA
| | - Thomas C Foster
- Department of Neuroscience, William L. and Evelyn F. McKnight Brain Institute, University of Florida Gainesville, FL, USA
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36
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Semi-automated registration-based anatomical labelling, voxel based morphometry and cortical thickness mapping of the mouse brain. J Neurosci Methods 2016; 267:62-73. [PMID: 27079699 DOI: 10.1016/j.jneumeth.2016.04.007] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2015] [Revised: 04/07/2016] [Accepted: 04/08/2016] [Indexed: 11/24/2022]
Abstract
BACKGROUND Morphoanatomical MRI methods have recently begun to be applied in the mouse. However, substantial differences in the anatomical organisation of human and rodent brain prevent a straightforward extension of clinical neuroimaging tools to mouse brain imaging. As a result, the vast majority of the published approaches rely on tailored routines that address single morphoanatomical readouts and typically lack a sufficiently-detailed description of the complex workflow required to process images and quantify structural alterations. NEW METHOD Here we provide a detailed description of semi-automated registration-based procedures for voxel based morphometry, cortical thickness estimation and automated anatomical labelling of the mouse brain. The approach relies on the sequential use of advanced image processing tools offered by ANTs, a flexible open source toolkit freely available to the scientific community. RESULTS To illustrate our procedures, we described their application to quantify morphological alterations in socially-impaired BTBR mice with respect to normosocial C57BL/6J controls, a comparison recently described by us and other research groups. We show that the approach can reliably detect both focal and large-scale grey matter alterations using complementary readouts. COMPARISON WITH EXISTING METHODS No detailed operational workflows for mouse imaging are available for direct comparison with our methods. However, empirical assessment of the mapped inter-strain differences is in good agreement with the findings of other groups using analogous approaches. CONCLUSION The detailed operational workflows described here are expected to help the implementation of rodent morphoanatomical methods by non-expert users, and ultimately promote the use of these tools across the preclinical neuroimaging community.
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Grandjean J, Derungs R, Kulic L, Welt T, Henkelman M, Nitsch RM, Rudin M. Complex interplay between brain function and structure during cerebral amyloidosis in APP transgenic mouse strains revealed by multi-parametric MRI comparison. Neuroimage 2016; 134:1-11. [PMID: 27033685 DOI: 10.1016/j.neuroimage.2016.03.042] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 03/11/2016] [Accepted: 03/17/2016] [Indexed: 11/28/2022] Open
Abstract
Alzheimer's disease is a fatal neurodegenerative disorder affecting the aging population. Neuroimaging methods, in particular magnetic resonance imaging (MRI), have helped reveal alterations in the brain structure, metabolism, and function of patients and in groups at risk of developing AD, yet the nature of these alterations is poorly understood. Neuroimaging in mice is attractive for investigating mechanisms underlying functional and structural changes associated with AD pathology. Several preclinical murine models of AD have been generated based on transgenic insertion of human mutated APP genes. Depending on the specific mutations, mouse strains express different aspects of amyloid pathology, e.g. intracellular amyloid-β (Aβ) aggregates, parenchymal plaques, or cerebral amyloid angiopathy. We have applied multi-parametric MRI in three transgenic mouse lines to compare changes in brain function with resting-state fMRI and structure with diffusion tensor imaging and high resolution anatomical imaging. E22ΔAβ developing intracellular Aβ aggregates did not present functional or structural alterations compared to their wild-type littermates. PSAPP mice displaying parenchymal amyloid plaques displayed mild functional changes within the supplementary and barrel field cortices, and increased isocortical volume relative to controls. Extensive reduction in functional connectivity in the sensory-motor cortices and within the default mode network, as well as local volume increase in the midbrain relative to wild-type have been observed in ArcAβ mice bearing intracellular Aβ aggregates as well as parenchymal and vascular amyloid deposits. Patterns of functional and structural changes appear to be strain-specific and not directly related to amyloid deposition.
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Affiliation(s)
- Joanes Grandjean
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland
| | - Rebecca Derungs
- Center for Neuroscience Research, University and ETH Zürich, Zürich, Switzerland; Division of Psychiatry Research, University of Zürich, Zürich, Switzerland
| | - Luka Kulic
- Center for Neuroscience Research, University and ETH Zürich, Zürich, Switzerland; Division of Psychiatry Research, University of Zürich, Zürich, Switzerland
| | - Tobias Welt
- Center for Neuroscience Research, University and ETH Zürich, Zürich, Switzerland; Division of Psychiatry Research, University of Zürich, Zürich, Switzerland
| | - Mark Henkelman
- Mouse Imaging Centre, Hospital for Sick Children, Toronto, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Canada
| | - Roger M Nitsch
- Center for Neuroscience Research, University and ETH Zürich, Zürich, Switzerland; Division of Psychiatry Research, University of Zürich, Zürich, Switzerland
| | - Markus Rudin
- Institute for Biomedical Engineering, University and ETH Zürich, Zürich, Switzerland; Center for Neuroscience Research, University and ETH Zürich, Zürich, Switzerland; Institute of Pharmacology and Toxicology, University of Zürich, Zürich, Switzerland.
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Dehabadi MH, Davis BM, Wong TK, Cordeiro MF. Retinal manifestations of Alzheimer's disease. Neurodegener Dis Manag 2015; 4:241-52. [PMID: 25095818 DOI: 10.2217/nmt.14.19] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is neurodegenerative condition and most common cause of dementia worldwide. Current criteria for its diagnosis and monitoring rely on subjective, expensive or invasive methods that lack sufficient sensitivity, such that a concrete diagnosis of AD can only be made postmortem. Given the structural similarities of the neuro-retina and central nervous system, researchers have shown many manifestations of AD to be detectible in the retinae of humans and transgenic models of AD. Due to the eye's unique optical properties allowing noninvasive in vivo imaging, the retina could provide a window for the early diagnosis and monitoring of AD long before symptom manifestation.
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Affiliation(s)
- Mohammad H Dehabadi
- Glaucoma & Retinal Neurodegeneration Research Group, Visual Neuroscience, UCL Institute of Ophthalmology, London, UK
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Lin L, Fu Z, Xu X, Wu S. Mouse brain magnetic resonance microscopy: Applications in Alzheimer disease. Microsc Res Tech 2015; 78:416-24. [PMID: 25810274 DOI: 10.1002/jemt.22489] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/23/2015] [Indexed: 01/26/2023]
Abstract
Over the past two decades, various Alzheimer's disease (AD) trangenetic mice models harboring genes with mutation known to cause familial AD have been created. Today, high-resolution magnetic resonance microscopy (MRM) technology is being widely used in the study of AD mouse models. It has greatly facilitated and advanced our knowledge of AD. In this review, most of the attention is paid to fundamental of MRM, the construction of standard mouse MRM brain template and atlas, the detection of amyloid plaques, following up on brain atrophy and the future applications of MRM in transgenic AD mice. It is believed that future testing of potential drugs in mouse models with MRM will greatly improve the predictability of drug effect in preclinical trials.
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Affiliation(s)
- Lan Lin
- Biomedical Engineering Department, College of Life Science and Bioengineering, Beijing University of Technology, Beijing, 100124, China
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Chen DQ, Strauss I, Hayes DJ, Davis KD, Hodaie M. Age-related changes in diffusion tensor imaging metrics of fornix subregions in healthy humans. Stereotact Funct Neurosurg 2015; 93:151-9. [PMID: 25790958 DOI: 10.1159/000368442] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 09/18/2014] [Indexed: 11/19/2022]
Abstract
OBJECTIVE White matter diffusivity measures of the fornix change with aging, which likely relates to changes in memory and cognition in older adults. Subregional variations in forniceal diffusivity may exist, given its heterogeneous anatomy and connectivity; however, these have not been closely examined in vivo. We examined diffusivity parameters (fractional anisotropy, FA; radial diffusivity, RD; axial diffusivity, AD) in forniceal subregions of healthy subjects and correlated them with age and hippocampal volume. METHODS Diffusion-weighted imaging and streamline tractography of the fornix were performed on 20 healthy, right-handed females (23-66 years). Six anatomical subregions were defined: midline (body, column, precommissural fornix) or lateral (fimbria, crura, postcommissural fornix). Regression analysis was performed comparing diffusivities against age. Hippocampal and ventricular volumes were also compared. RESULTS Diffusivity values revealed statistical changes with age in both midline and lateralized subregions. The fornix body and left crus showed age-related alterations in all metrics (FA, RD, AD), whereas only right crus FA was altered. There was no significant change in hippocampal volumes, suggesting that forniceal changes may precede hippocampal age-related changes. CONCLUSIONS Age-related changes in fornix diffusivity measures appear subregion dependent and asymmetrical. Specific subregion diffusivity measures may be a more sensitive aging marker than hippocampal volume change.
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Affiliation(s)
- David Qixiang Chen
- Institute of Medical Science, Faculty of Medicine, University of Toronto, Toronto, Ont., Canada
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Sala-Llonch R, Lladó A, Fortea J, Bosch B, Antonell A, Balasa M, Bargalló N, Bartrés-Faz D, Molinuevo JL, Sánchez-Valle R. Evolving brain structural changes in PSEN1 mutation carriers. Neurobiol Aging 2014; 36:1261-70. [PMID: 25638532 DOI: 10.1016/j.neurobiolaging.2014.12.022] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 12/16/2014] [Accepted: 12/17/2014] [Indexed: 02/04/2023]
Abstract
Familial Alzheimer's disease provides the opportunity to investigate brain changes even before the symptoms onset. We performed a structural magnetic resonance imaging (MRI) study in 38 participants from families with presenilin 1 gene mutations: 11 symptomatic mutation carriers, 13 asymptomatic mutation carriers (AMC), with a mean of 16.22 years before the estimated appearance of symptoms, and 14 noncarriers. A subset of subjects was studied longitudinally 2 and 4 years after the first scan. We found decreased cortical thickness (CTh) and volume in cortical and subcortical structures in symptomatic mutation carriers, with progressive loss over time. In AMC, we found increased CTh and volume in temporoparietal regions and in precuneus-posterior cingulate compared with controls at baseline. Longitudinal studies in AMC, by contrast, showed accelerated rates of CTh loss in precuneus-posterior cingulate and superior parietal, right lateral temporal and left orbitofrontal, and middle frontal regions. These findings suggest that brain structure in presenilin 1 mutation carriers follows nonlinear trajectories, with regional increases during the very early presymptomatic period. Initial neuroinflammation and/or accumulation of amyloid species followed by neurodegeneration, or congenital morphometric differences, may explain the observed features.
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Affiliation(s)
- Roser Sala-Llonch
- Department of Psychiatry and Clinical Psychobiology, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Lladó
- Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Alzheimer's Disease and Other Cognitive Disorders Unit, Department of Neurology, Hospital Clínic, Barcelona, Spain
| | - Juan Fortea
- Memory Unit, Department of Neurology, Hospital de Sant Pau, Barcelona, Spain
| | - Beatriz Bosch
- Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Alzheimer's Disease and Other Cognitive Disorders Unit, Department of Neurology, Hospital Clínic, Barcelona, Spain
| | - Anna Antonell
- Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Alzheimer's Disease and Other Cognitive Disorders Unit, Department of Neurology, Hospital Clínic, Barcelona, Spain
| | - Mircea Balasa
- Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Alzheimer's Disease and Other Cognitive Disorders Unit, Department of Neurology, Hospital Clínic, Barcelona, Spain
| | - Nuria Bargalló
- Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Department of Radiology, Hospital Clínic, Barcelona, Spain
| | - David Bartrés-Faz
- Department of Psychiatry and Clinical Psychobiology, Universitat de Barcelona, Barcelona, Spain; Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain
| | - José Luis Molinuevo
- Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Alzheimer's Disease and Other Cognitive Disorders Unit, Department of Neurology, Hospital Clínic, Barcelona, Spain
| | - Raquel Sánchez-Valle
- Institut d'Investigació Biomèdica August Pi i Sunyer (IDIBAPS), Barcelona, Spain; Alzheimer's Disease and Other Cognitive Disorders Unit, Department of Neurology, Hospital Clínic, Barcelona, Spain.
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Jeffery N, Mendias C. Endocranial and masticatory muscle volumes in myostatin-deficient mice. ROYAL SOCIETY OPEN SCIENCE 2014; 1:140187. [PMID: 26064569 PMCID: PMC4448778 DOI: 10.1098/rsos.140187] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/21/2014] [Accepted: 08/15/2014] [Indexed: 06/04/2023]
Abstract
Structural and functional trade-offs are integral to the evolution of the mammalian skull and its development. This paper examines the potential for enlargement of the masticatory musculature to limit the size of the endocranial cavity by studying a myostatin-deficient mouse model of hypermuscularity (MSTN-/-). The study tests the null prediction that the larger MSTN-/- mice have larger brains compared with wild-type (WT) mice in order to service the larger muscles. Eleven post-mortem MSTN-/- mice and 12 WT mice were imaged at high resolution using contrast enhanced micro-CT. Masticatory muscle volumes (temporalis, masseter, internal and external pterygoids) and endocranial volumes were measured on the basis of two-dimensional manual tracings and the Cavalieri principle. Volumes were compared using Kruskal-Wallis and Student's t-tests. Results showed that the masticatory muscles of the MSTN-/- mice were significantly larger than in the WT mice. Increases were in the region of 17-36% depending on the muscle. Muscles increased in proportion to each other, maintaining percentages in the region of 5, 10, 21 and 62% of total muscle volume for the external ptyergoid, internal pterygoid, temporalis and masseter, respectively. Kruskal-Wallis and t-tests demonstrated that the endocranial volume was significantly larger in the WT mice, approximately 16% larger on average than that seen in the MSTN-/- mice. This comparative reduction of MSTN-/- endocranial size could not be explained in terms of observer bias, ageing, sexual dimorphism or body size scaling. That the results showed a reduction of brain size associated with an increase of muscle size falsifies the null prediction and lends tentative support to the view that the musculature influences brain growth. It remains to be determined whether the observed effect is primarily physical, nutritional, metabolic or molecular in nature.
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Affiliation(s)
- Nathan Jeffery
- Department of Musculoskeletal Biology, Institute of Ageing and Chronic Disease, University of Liverpool, Sherrington Building, Ashton Street, Liverpool L69 3GE, UK
| | - Christopher Mendias
- Department of Orthopaedic Surgery, University of Michigan, Ann Arbor, MI, USA
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Perez-Gonzalez JL, Yanez-Suarez O, Bribiesca E, Cosío FA, Jiménez JR, Medina-Bañuelos V. Description and classification of normal and pathological aging processes based on brain magnetic resonance imaging morphology measures. J Med Imaging (Bellingham) 2014; 1:034002. [PMID: 26158061 PMCID: PMC4478725 DOI: 10.1117/1.jmi.1.3.034002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2014] [Revised: 07/15/2014] [Accepted: 09/15/2014] [Indexed: 11/14/2022] Open
Abstract
We present a discrete compactness (DC) index, together with a classification scheme, based both on the size and shape features extracted from brain volumes, to determine different aging stages: healthy controls (HC), mild cognitive impairment (MCI), and Alzheimer's disease (AD). A set of 30 brain magnetic resonance imaging (MRI) volumes for each group was segmented and two indices were measured for several structures: three-dimensional DC and normalized volumes (NVs). The discrimination power of these indices was determined by means of the area under the curve (AUC) of the receiver operating characteristic, where the proposed compactness index showed an average AUC of 0.7 for HC versus MCI comparison, 0.9 for HC versus AD separation, and 0.75 for MCI versus AD groups. In all cases, this index outperformed the discrimination capability of the NV. Using selected features from the set of DC and NV measures, three support vector machines were optimized and validated for the pairwise separation of the three classes. Our analysis shows classification rates of up to 98.3% between HC and AD, 85% between HC and MCI, and 93.3% for MCI and AD separation. These results outperform those reported in the literature and demonstrate the viability of the proposed morphological indices to classify different aging stages.
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Affiliation(s)
- Jorge Luis Perez-Gonzalez
- Universidad Autónoma Metropolitana, Neuroimaging Laboratory, Department of Electrical Engineering, Iztapalapa, México D.F. 09340, Mexico
| | - Oscar Yanez-Suarez
- Universidad Autónoma Metropolitana, Neuroimaging Laboratory, Department of Electrical Engineering, Iztapalapa, México D.F. 09340, Mexico
| | - Ernesto Bribiesca
- Universidad Nacional Autónoma de México, IIMAS, Department of Computer Science, México D.F. 04510, Mexico
| | - Fernando Arámbula Cosío
- Universidad Nacional Autónoma de México, Biomedical Imaging Lab. Centro de Ciencias Aplicadas y Desarrollo Tecnológico, México D.F. 04510, Mexico
| | - Juan Ramón Jiménez
- Universidad Autónoma Metropolitana, Neuroimaging Laboratory, Department of Electrical Engineering, Iztapalapa, México D.F. 09340, Mexico
| | - Veronica Medina-Bañuelos
- Universidad Autónoma Metropolitana, Neuroimaging Laboratory, Department of Electrical Engineering, Iztapalapa, México D.F. 09340, Mexico
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Oishi K, Lyketsos CG. Alzheimer's disease and the fornix. Front Aging Neurosci 2014; 6:241. [PMID: 25309426 PMCID: PMC4161001 DOI: 10.3389/fnagi.2014.00241] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2014] [Accepted: 08/22/2014] [Indexed: 11/27/2022] Open
Abstract
Alzheimer’s disease (AD) is the most common form of neurodegenerative dementia. Researchers have long been focused on the cortical pathology of AD, since the most important pathologic features are the senile plaques found in the cortex, and the neurofibrillary tangles and neuronal loss that begin in the entorhinal cortex and the hippocampus. In addition to these gray matter (GM) structures, histopathological studies indicate that the white matter (WM) is also a good target for both the early diagnosis of AD and for monitoring disease progression. The fornix is a WM bundle that constitutes a core element of the limbic circuits, and is one of the most important anatomical structures related to memory. Functional and anatomical features of the fornix have naturally captured researchers’ attention as possible diagnostic and prognostic markers of AD. Indeed, neurodegeneration of the fornix has been histologically observed in AD, and growing evidence indicates that the alterations seen in the fornix are potentially a good marker to predict future conversion from mild cognitive impairment (MCI) to AD, and even from cognitively normal individuals to AD. The degree of alteration is correlated with the degree of memory impairment, indicating the potential for the use of the fornix as a functional marker. Moreover, there have been attempts to stimulate the fornix using deep brain stimulation (DBS) to augment cognitive function in AD, and ongoing research has suggested positive effects of DBS on brain glucose metabolism in AD patients. On the other hand, disease specificity for fornix degeneration, methodologies to evaluate fornix degeneration, and the clinical significance of the fornix DBS, especially for the long-term impact on the quality of life, are mostly unknown and need to be elucidated.
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Affiliation(s)
- Kenichi Oishi
- The Russell H. Morgan Department of Radiology and Radiological Science, School of Medicine, Johns Hopkins University Baltimore, MD, USA
| | - Constantine G Lyketsos
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins Bayview and Johns Hopkins Medicine Baltimore, MD, USA
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Fortea J, Vilaplana E, Alcolea D, Carmona-Iragui M, Sánchez-Saudinos MB, Sala I, Antón-Aguirre S, González S, Medrano S, Pegueroles J, Morenas E, Clarimón J, Blesa R, Lleó A. Cerebrospinal fluid β-amyloid and phospho-tau biomarker interactions affecting brain structure in preclinical Alzheimer disease. Ann Neurol 2014; 76:223-30. [PMID: 24852682 DOI: 10.1002/ana.24186] [Citation(s) in RCA: 102] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 05/19/2014] [Accepted: 05/19/2014] [Indexed: 11/08/2022]
Abstract
OBJECTIVE To assess the relationships between core cerebrospinal fluid (CSF) biomarkers and cortical thickness (CTh) in preclinical Alzheimer disease (AD). METHODS In this cross-sectional study, normal controls (n = 145) from the Alzheimer's Disease Neuroimaging Initiative underwent structural 3T magnetic resonance imaging (MRI) and lumbar puncture. CSF β-amyloid1-42 (Aβ) and phospho-tau₁₈₁p (p-tau) levels were measured by Luminex assays. Samples were dichotomized using published cutoffs (Aβ(+) /Aβ(-) and p-tau(+) /ptau(-)). CTh was measured by Freesurfer. CTh difference maps were derived from interaction and correlation analyses. Clusters from the interaction analysis were isolated to analyze the directionality of the interaction by analysis of covariance. RESULTS We found a significant biomarker interaction between CSF Aβ and CSF p-tau levels affecting brain structure. Cortical atrophy only occurs in subjects with both Aβ(+) and p-tau(+). The stratified correlation analyses showed that the relationship between p-tau and CTh is modified by Aβ status and the relationship between Aβ and CTh is modified by p-tau status. p-Tau-dependent thinning was found in different cortical regions in Aβ(+) subjects but not in Aβ(-) subjects. Cortical thickening was related to decreasing CSF Aβ values in the absence of abnormal p-tau, but no correlations were found in p-tau(+) subjects. INTERPRETATION Our data suggest that interactions between biomarkers in AD result in a 2-phase phenomenon of pathological cortical thickening associated with low CSF Aβ, followed by atrophy once CSF p-tau becomes abnormal. These interactions should be considered in clinical trials in preclinical AD, both when selecting patients and when using MRI as a surrogate marker of efficacy.
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Affiliation(s)
- Juan Fortea
- Memory Unit, Department of Neurology, Hospital de la Santa Creu i Sant Pau - Biomedical Research Institute Sant Pau - Universitat Autònoma de Barcelona; Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas - CIBERNED
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Tse YC, Montoya I, Wong AS, Mathieu A, Lissemore J, Lagace DC, Wong TP. A longitudinal study of stress-induced hippocampal volume changes in mice that are susceptible or resilient to chronic social defeat. Hippocampus 2014; 24:1120-8. [DOI: 10.1002/hipo.22296] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/18/2014] [Indexed: 02/02/2023]
Affiliation(s)
- Yiu Chung Tse
- Douglas Mental Health University Institute, McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
| | - Ixchel Montoya
- Douglas Mental Health University Institute, McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
| | - Alice S. Wong
- Douglas Mental Health University Institute, McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
| | - Axel Mathieu
- Douglas Mental Health University Institute, McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
| | - Jennifer Lissemore
- Douglas Mental Health University Institute, McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
| | - Diane C. Lagace
- Department of Cellular and Molecular Medicine; University of Ottawa; Ottawa Ontario Canada
| | - Tak Pan Wong
- Douglas Mental Health University Institute, McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
- Department of Psychiatry; McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
- Department of Pharmacology and Therapeutics; McGill University; 6875 LaSalle Boulevard Montreal Quebec Canada
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Sawiak SJ, Picq JL, Dhenain M. Voxel-based morphometry analyses of in vivo MRI in the aging mouse lemur primate. Front Aging Neurosci 2014; 6:82. [PMID: 24834052 PMCID: PMC4018531 DOI: 10.3389/fnagi.2014.00082] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 04/16/2014] [Indexed: 11/23/2022] Open
Abstract
Cerebral atrophy is one of the most widely brain alterations associated to aging. A clear relationship has been established between age-associated cognitive impairments and cerebral atrophy. The mouse lemur (Microcebus murinus) is a small primate used as a model of age-related neurodegenerative processes. It is the first non-human primate in which cerebral atrophy has been correlated with cognitive deficits. Previous studies of cerebral atrophy in this model were based on time consuming manual delineation or measurement of selected brain regions from magnetic resonance images (MRI). These measures could not be used to analyse regions that cannot be easily outlined such as the nucleus basalis of Meynert or the subiculum. In humans, morphometric assessment of structural changes with age is generally performed with automated procedures such as voxel-based morphometry (VBM). The objective of our work was to perform user-independent assessment of age-related morphological changes in the whole brain of large mouse lemur populations thanks to VBM. The study was based on the SPMMouse toolbox of SPM 8 and involved thirty mouse lemurs aged from 1.9 to 11.3 years. The automatic method revealed for the first time atrophy in regions where manual delineation is prohibitive (nucleus basalis of Meynert, subiculum, prepiriform cortex, Brodmann areas 13–16, hypothalamus, putamen, thalamus, corpus callosum). Some of these regions are described as particularly sensitive to age-associated alterations in humans. The method revealed also age-associated atrophy in cortical regions (cingulate, occipital, parietal), nucleus septalis, and the caudate. Manual measures performed in some of these regions were in good agreement with results from automatic measures. The templates generated in this study as well as the toolbox for SPM8 can be downloaded. These tools will be valuable for future evaluation of various treatments that are tested to modulate cerebral aging in lemurs.
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Affiliation(s)
- Stephen J Sawiak
- Wolfson Brain Imaging Centre, University of Cambridge, Addenbrooke's Hospital Cambridge, UK ; Behavioural and Clinical Neuroscience Institute, University of Cambridge Cambridge, UK
| | - Jean-Luc Picq
- EA, 2027: Laboratoire de Psychopathologie et de Neuropsychologie, Université Paris 8 St-Denis, France ; CEA, DSV, I2BM, MIRCen Fontenay-aux-Roses, France ; CNRS, URA 2210 Fontenay-aux-Roses, France
| | - Marc Dhenain
- CEA, DSV, I2BM, MIRCen Fontenay-aux-Roses, France ; CNRS, URA 2210 Fontenay-aux-Roses, France
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Hayes K, Buist R, Vincent TJ, Thiessen JD, Zhang Y, Zhang H, Wang J, Summers AR, Kong J, Li XM, Martin M. Comparison of manual and semi-automated segmentation methods to evaluate hippocampus volume in APP and PS1 transgenic mice obtained via in vivo magnetic resonance imaging. J Neurosci Methods 2013; 221:103-11. [PMID: 24091139 DOI: 10.1016/j.jneumeth.2013.09.014] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 08/23/2013] [Accepted: 09/21/2013] [Indexed: 11/28/2022]
Abstract
BACKGROUND Magnetic resonance imaging (MRI) of transgenic mouse models of Alzheimer's disease is valuable to understand better the structural changes that occur in the brain and could provide a means to test drug treatments. A hallmark pathological feature of Alzheimer's disease is atrophy of the hippocampus, which is an early biomarker of the disease. MRI can be used to detect and monitor this biomarker. METHOD Repeated measurements using in vivo 3D T2-weighted imaging of mice were used to assess the methods. Each mouse was imaged twice in one week and twice the following week and no changes in volume were expected. The hippocampus was segmented both manually and semi-automatically. Registration was done to gain information on shape changes. The volumes from each mouse were compared intra-mouse, between mice and to hippocampus volume values in the literature. RESULTS A reliable method was developed which was able to detect difference in volumes of hippocampus between mice when performed by a single individual. The semi-automated segmentation was unable to detect the same level of differences. The semi-automated segmentation method gave larger hippocampus volumes, with 78-87% reliability between the manual and semi-automated segmentation. Although more accurate, the manual segmentation is laborious and suffers from inter- and intra-variability. CONCLUSION These results suggest that manual segmentation is still considered the most reliable segmentation method for small structures. However, if performing longitudinal studies, where there is at least one year between imaging sessions, the segmentation should be done all at once at the end of all the imaging sessions. If segmentation is done after each imaging session, with at least a year passing between segmentations, very small variations in volumes can be missed. This method provides a means to quantify the volume of the hippocampus in a live mouse using manual segmentation, which is the first step toward studying hippocampus atrophy in a mouse model of Alzheimer's disease.
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Affiliation(s)
- Kerrie Hayes
- Department of Biology, University of Winnipeg, 515 Portage Avenue, Winnipeg, MB, Canada R3B 2E9.
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Impaired structural correlates of memory in Alzheimer's disease mice. NEUROIMAGE-CLINICAL 2013; 3:290-300. [PMID: 24273714 PMCID: PMC3814975 DOI: 10.1016/j.nicl.2013.08.017] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2013] [Revised: 08/14/2013] [Accepted: 08/30/2013] [Indexed: 12/27/2022]
Abstract
The healthy adult brain demonstrates robust learning-induced neuroanatomical plasticity. While altered neuroanatomical plasticity is suspected to be a factor mitigating the progressive cognitive decline in Alzheimer's disease (AD), it is not known to what extent this plasticity is affected by AD. We evaluated whether spatial learning and memory-induced neuroanatomical plasticity are diminished in an adult mouse model of AD (APP mice) featuring amyloid beta-driven cognitive and cerebrovascular dysfunction. We also evaluated the effect of early, long-term pioglitazone-treatment on functional hyperemia, spatial learning and memory, and associated neuroanatomical plasticity. Using high-resolution post-mortem MRI and deformation-based morphometry, we demonstrate spatial learning and memory-induced focal volume increase in the hippocampus of wild-type mice, an effect that was severely attenuated in APP mice, consistent with their unsuccessful performance in the spatial Morris water maze. These findings implicate impaired neuroanatomical plasticity as an important contributing factor to cognitive deficits in the APP mouse model of AD. Pioglitazone-treatment in APP mice completely rescued functional hyperemia and exerted beneficial effects on spatial learning and memory-recall, but it did not improve hippocampal plasticity.
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Cortical atrophy and hypoperfusion in a transgenic mouse model of Alzheimer's disease. Neurobiol Aging 2013; 34:1644-52. [DOI: 10.1016/j.neurobiolaging.2012.11.022] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2012] [Revised: 11/24/2012] [Accepted: 11/26/2012] [Indexed: 01/24/2023]
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