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Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults

One of the earliest indicators of Alzheimer’s disease pathology is the presence of beta-amyloid (Aβ) protein deposition. Significant amyloid deposition is evident even in older adults who exhibit little or no overt cognitive or memory impairment. Hippocampal-based processes that help distinguish bet...

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Autores principales: Webb, Christina E., Foster, Chris M., Horn, Marci M., Kennedy, Kristen M., Rodrigue, Karen M.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7813158/
https://www.ncbi.nlm.nih.gov/pubmed/32736001
http://dx.doi.org/10.1016/j.neuroimage.2020.117199
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author Webb, Christina E.
Foster, Chris M.
Horn, Marci M.
Kennedy, Kristen M.
Rodrigue, Karen M.
author_facet Webb, Christina E.
Foster, Chris M.
Horn, Marci M.
Kennedy, Kristen M.
Rodrigue, Karen M.
author_sort Webb, Christina E.
collection PubMed
description One of the earliest indicators of Alzheimer’s disease pathology is the presence of beta-amyloid (Aβ) protein deposition. Significant amyloid deposition is evident even in older adults who exhibit little or no overt cognitive or memory impairment. Hippocampal-based processes that help distinguish between highly similar memory representations may be the most susceptible to early disease pathology. Amyloid associations with memory have been difficult to establish, possibly because typical memory assessments do not tax hippocampal operations sufficiently. Thus, the present study utilized a spatial mnemonic discrimination task designed to tax hippocampal pattern separation/completion processes in a sample of cognitively normal middle-aged and older adults (53–98 years old) who underwent PET (18)F-Florbetapir Aβ scanning. The degree of interference between studied and new information varied, allowing for an examination of mnemonic discrimination as a function of mnemonic similarity. Results indicated that greater beta-amyloid burden was associated with poorer discrimination across decreasing levels of interference, suggesting that even subtle elevation of beta-amyloid in cognitively normal adults is associated with impoverished performance on a hippocampally demanding memory task. The present study demonstrates that degree of amyloid burden negatively impacts the ability of aging adults to accurately distinguish old from increasingly distinct new information, providing novel insight into the cognitive expression of beta-amyloid neuropathology
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spelling pubmed-78131582021-01-18 Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults Webb, Christina E. Foster, Chris M. Horn, Marci M. Kennedy, Kristen M. Rodrigue, Karen M. Neuroimage Article One of the earliest indicators of Alzheimer’s disease pathology is the presence of beta-amyloid (Aβ) protein deposition. Significant amyloid deposition is evident even in older adults who exhibit little or no overt cognitive or memory impairment. Hippocampal-based processes that help distinguish between highly similar memory representations may be the most susceptible to early disease pathology. Amyloid associations with memory have been difficult to establish, possibly because typical memory assessments do not tax hippocampal operations sufficiently. Thus, the present study utilized a spatial mnemonic discrimination task designed to tax hippocampal pattern separation/completion processes in a sample of cognitively normal middle-aged and older adults (53–98 years old) who underwent PET (18)F-Florbetapir Aβ scanning. The degree of interference between studied and new information varied, allowing for an examination of mnemonic discrimination as a function of mnemonic similarity. Results indicated that greater beta-amyloid burden was associated with poorer discrimination across decreasing levels of interference, suggesting that even subtle elevation of beta-amyloid in cognitively normal adults is associated with impoverished performance on a hippocampally demanding memory task. The present study demonstrates that degree of amyloid burden negatively impacts the ability of aging adults to accurately distinguish old from increasingly distinct new information, providing novel insight into the cognitive expression of beta-amyloid neuropathology 2020-07-29 2020-11-01 /pmc/articles/PMC7813158/ /pubmed/32736001 http://dx.doi.org/10.1016/j.neuroimage.2020.117199 Text en This is an open access article under the CC BY-NC-ND license. (http://creativecommons.org/licenses/by-nc-nd/4.0/)
spellingShingle Article
Webb, Christina E.
Foster, Chris M.
Horn, Marci M.
Kennedy, Kristen M.
Rodrigue, Karen M.
Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults
title Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults
title_full Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults
title_fullStr Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults
title_full_unstemmed Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults
title_short Beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults
title_sort beta-amyloid burden predicts poorer mnemonic discrimination in cognitively normal older adults
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7813158/
https://www.ncbi.nlm.nih.gov/pubmed/32736001
http://dx.doi.org/10.1016/j.neuroimage.2020.117199
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