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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Reichel JM, Bedenk BT, Gassen NC, Hafner K, Bura SA, Almeida-Correa S, Genewsky A, Dedic N, Giesert F, Agarwal A, Nave KA, Rein T, Czisch M, Deussing JM, Wotjak CT. Beware of your Cre-Ation: lacZ expression impairs neuronal integrity and hippocampus-dependent memory. Hippocampus 2016; 26:1250-64. [PMID: 27101945 DOI: 10.1002/hipo.22601] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/08/2016] [Indexed: 12/28/2022]
Abstract
Expression of the lacZ-sequence is a widely used reporter-tool to assess the transgenic and/or transfection efficacy of a target gene in mice. Once activated, lacZ is permanently expressed. However, protein accumulation is one of the hallmarks of neurodegenerative diseases. Furthermore, the protein product of the bacterial lacZ gene is ß-galactosidase, an analog to the mammalian senescence-associated ß-galactosidase, a molecular marker for aging. Therefore we studied the behavioral, structural and molecular consequences of lacZ expression in distinct neuronal sub-populations. lacZ expression in cortical glutamatergic neurons resulted in severe impairments in hippocampus-dependent memory accompanied by marked structural alterations throughout the CNS. In contrast, GFP expression or the expression of the ChR2/YFP fusion product in the same cell populations did not result in either cognitive or structural deficits. GABAergic lacZ expression caused significantly decreased hyper-arousal and mild cognitive deficits. Attenuated structural and behavioral consequences of lacZ expression could also be induced in adulthood, and lacZ transfection in neuronal cell cultures significantly decreased their viability. Our findings provide a strong caveat against the use of lacZ reporter mice for phenotyping studies and point to a particular sensitivity of the hippocampus formation to detrimental consequences of lacZ expression. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- J M Reichel
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.,Department of Molecular Pharmacology, Albert Einstein College of Medicine, 10461, Bronx, New York
| | - B T Bedenk
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.,Core Unit Neuroimaging, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - N C Gassen
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - K Hafner
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - S A Bura
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - S Almeida-Correa
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - A Genewsky
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - N Dedic
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - F Giesert
- Institute of Developmental Genetics, Helmholtz Zentrum Muenchen, German Research Center for Environmental Health (GmbH), Ingolstaedter Landstrasse 1, Neuherberg, D-85764, Germany
| | - A Agarwal
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University, Baltimore, Maryland
| | - K-A Nave
- Department of Neurogenetics, Max Planck Institute of Experimental Medicine, Goettingen, 37075, Germany
| | - T Rein
- Department of Translational Research in Psychiatry, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - M Czisch
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.,Core Unit Neuroimaging, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - J M Deussing
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany
| | - C T Wotjak
- Department of Stress Neurobiology and Neurogenetics, Max Planck Institute of Psychiatry, 80804, Munich, Germany.
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Schoen M, Reichel JM, Demestre M, Putz S, Deshpande D, Proepper C, Liebau S, Schmeisser MJ, Ludolph AC, Michaelis J, Boeckers TM. Super-Resolution Microscopy Reveals Presynaptic Localization of the ALS/FTD Related Protein FUS in Hippocampal Neurons. Front Cell Neurosci 2016; 9:496. [PMID: 26834559 PMCID: PMC4709451 DOI: 10.3389/fncel.2015.00496] [Citation(s) in RCA: 52] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 12/09/2015] [Indexed: 12/12/2022] Open
Abstract
Fused in Sarcoma (FUS) is a multifunctional RNA-/DNA-binding protein, which is involved in the pathogenesis of the neurodegenerative disorders amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). A common hallmark of these disorders is the abnormal accumulation of mutated FUS protein in the cytoplasm. Under normal conditions FUS is confined to the nuclear compartment, in neurons, however, additional somatodendritic localization can be observed. In this study, we carefully analyzed the subcellular localization of endogenous FUS at synaptic sites of hippocampal neurons which are among the most affected cell types in FTD with FUS pathology. We could confirm a strong nuclear localization of FUS as well as its prominent and widespread neuronal expression throughout the adult and developing rat brain, particularly in the hippocampus, the cerebellum and the outer layers of the cortex. Intriguingly, FUS was also consistently observed at synaptic sites as detected by neuronal subcellular fractionation as well as by immunolabeling. To define a pre- and/or postsynaptic localization of FUS, we employed super-resolution fluorescence localization microscopy. FUS was found to be localized within the axon terminal in close proximity to the presynaptic vesicle protein Synaptophysin1 and adjacent to the active zone protein Bassoon, but well separated from the postsynaptic protein PSD-95. Having shown the presynaptic localization of FUS in the nervous system, a novel extranuclear role of FUS at neuronal contact sites has to be considered. Since there is growing evidence that local presynaptic translation might also be an important mechanism for plasticity, FUS - like the fragile X mental retardation protein FMRP - might act as one of the presynaptic RNA-binding proteins regulating this machinery. Our observation of presynaptic FUS should foster further investigations to determine its role in neurodegenerative diseases such as ALS and FTD.
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Affiliation(s)
- Michael Schoen
- Institute for Anatomy and Cell Biology, Ulm University Ulm, Germany
| | | | - Maria Demestre
- Institute for Anatomy and Cell Biology, Ulm University Ulm, Germany
| | - Stefan Putz
- Institute for Anatomy and Cell Biology, Ulm UniversityUlm, Germany; Department of Neurology, Ulm UniversityUlm, Germany
| | | | | | - Stefan Liebau
- Institute of Neuroanatomy, Eberhard Karls University Tübingen Tübingen, Germany
| | - Michael J Schmeisser
- Institute for Anatomy and Cell Biology, Ulm UniversityUlm, Germany; Department of Neurology, Ulm UniversityUlm, Germany
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