Impaired AMPA signaling and cytoskeletal alterations induce early synaptic dysfunction in a mouse model of Alzheimer's disease |
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| Authors: | David Baglietto‐Vargas Gilberto Aleph Prieto Agenor Limon Stefania Forner Carlos J. Rodriguez‐Ortiz Kenji Ikemura Rahasson R. Ager Rodrigo Medeiros Laura Trujillo‐Estrada Alessandra C. Martini Masashi Kitazawa Jose C. Davila Carl W. Cotman Antonia Gutierrez Frank M. LaFerla |
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| Affiliation: | 1. Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, California;2. Department of Neurobiology and Behavior, University of California, Irvine, California;3. Department of Cell Biology, Genetic and Physiology, Faculty of Sciences, Biomedical Research Institute of Malaga (IBIMA), Networking Research Center on Neurodegenerative Diseases (CIBERNED), University of Malaga, Malaga, Spain;4. Department of Psychiatry and Human Behavior, University of California, Irvine, California;5. Division of Occupational and Environmental Medicine, Department of Medicine, Center for Occupational and Environmental Health (COEH), University of California, Irvine, California;6. Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Qld, Australia;7. Department of Neurology, University of California, Irvine, California |
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| Abstract: | Alzheimer's disease (AD) is a devastating neurodegenerative disorder that impairs memory and causes cognitive and psychiatric deficits. New evidences indicate that AD is conceptualized as a disease of synaptic failure, although the molecular and cellular mechanisms underlying these defects remain to be elucidated. Determining the timing and nature of the early synaptic deficits is critical for understanding the progression of the disease and for identifying effective targets for therapeutic intervention. Using single‐synapse functional and morphological analyses, we find that AMPA signaling, which mediates fast glutamatergic synaptic transmission in the central nervous system (CNS), is compromised early in the disease course in an AD mouse model. The decline in AMPA signaling is associated with changes in actin cytoskeleton integrity, which alters the number and the structure of dendritic spines. AMPA dysfunction and spine alteration correlate with the presence of soluble but not insoluble Aβ and tau species. In particular, we demonstrate that these synaptic impairments can be mitigated by Aβ immunotherapy. Together, our data suggest that alterations in AMPA signaling and cytoskeletal processes occur early in AD. Most important, these deficits are prevented by Aβ immunotherapy, suggesting that existing therapies, if administered earlier, could confer functional benefits. |
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| Keywords: | actin cytoskeleton Alzheimer's disease AMPA receptor Aβ immunotherapy synaptic impairment |
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