title: Impairments in spatial representations and rhythmic coordination of place cells in the 3xTg mouse model of Alzheimer's disease.
abstract: Alzheimer's disease (AD) is an irreversible and highly progressive neurodegenerative disease. Clinically, patients with AD display impairments in episodic and spatial memory. However, the underlying neuronal dysfunctions that result in these impairments remain poorly understood. The hippocampus is crucial for spatial and episodic memory, and thus we tested the hypothesis that abnormal neuronal representations of space in the hippocampus contribute to memory deficits in AD. To test this hypothesis, we recorded spikes from place cells in hippocampal subfield CA1, together with corresponding rhythmic activity in local field potentials, in the 3xTg AD mouse model. We observed disturbances in place cell firing patterns, many of which were consistent with place cell disturbances reported in other rodent models of AD. We found place cell representations of space to be unstable in 3xTg mice compared to control mice. Furthermore, coordination of place cell firing by hippocampal rhythms was disrupted in 3xTg mice. Specifically, a smaller proportion of place cells from 3xTg mice were significantly phase-locked to theta and slow gamma rhythms, and the theta and slow gamma phases at which spikes occurred were also altered. Remarkably, these disturbances were observed at an age before detectable Aβ pathology had developed. Consistencies between these findings in 3xTg mice and previous findings from other AD models suggest that disturbances in place cell firing and hippocampal rhythms are related to AD rather than reflecting peculiarities inherent to a particular transgenic model. Thus, disturbed rhythmic organization of place cell activity may contribute to unstable spatial representations, and related spatial memory deficits, in AD. © 2017 Wiley Periodicals, Inc.
authors.affiliation: Center for Learning and Memory, The University of Texas at Austin, Austin, Texas, 78712.|Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712.
authors.forename: Alexandra J
authors.identifier: 0000-0002-1510-3585
authors.initials: AJ
authors.lastname: Mably
authors.affiliation: Center for Learning and Memory, The University of Texas at Austin, Austin, Texas, 78712.|Institute for Neuroscience, The University of Texas at Austin, Austin, Texas, 78712.
authors.forename: Brian J
authors.initials: BJ
authors.lastname: Gereke
authors.affiliation: Center for Learning and Memory, The University of Texas at Austin, Austin, Texas, 78712.|Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712.
authors.forename: Dylan T
authors.initials: DT
authors.lastname: Jones
authors.affiliation: Center for Learning and Memory, The University of Texas at Austin, Austin, Texas, 78712.|Department of Neuroscience, The University of Texas at Austin, Austin, Texas, 78712.|Institute for Neuroscience, The University of Texas at Austin, Austin, Texas, 78712.
authors.forename: Laura Lee
authors.initials: LL
authors.lastname: Colgin
mesh_terms: D000200:Action Potentials / Q000502:physiology; D000544:Alzheimer Disease / Q000473:pathology / Q000503:physiopathology*; D016564:Amyloid beta-Protein Precursor / Q000235:genetics / Q000378:metabolism; D000818:Animals; D004195:Disease Models, Animal; D004567:Electrodes, Implanted; D065818:Gamma Rhythm / Q000502:physiology; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology*; D006801:Humans; D007150:Immunohistochemistry; D008297:Male; D057507:Mice, 129 Strain; D008822:Mice, Transgenic; D000071037:Place Cells / Q000473:pathology / Q000502:physiology*; D013028:Space Perception / Q000502:physiology*; D013037:Spatial Behavior / Q000502:physiology; D013826:Theta Rhythm / Q000502:physiology; D016875:tau Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: C545487:APP protein, human; D016564:Amyloid beta-Protein Precursor; C054369:MAPT protein, human; D016875:tau Proteins
keywords: CA1; gamma rhythms; hippocampus; place fields; theta rhythms