Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Pattern separation deficits associated with increased hippocampal CA3 and dentate gyrus activity in nondemented older adults

Pattern separation deficits associated with increased hippocampal CA3 and dentate gyrus activity... There is widespread evidence that memory deteriorates with aging, however the exact mechanisms that underlie these changes are not well understood. Given the growing size of the aging population, there is an imperative to study age‐related neurocognitive changes in order to better parse healthy from pathological aging. Using a behavioral paradigm that taxes pattern separation (the ability to differentiate novel yet similar information from previously learned information and thus avoid interference), we investigated age‐related neural changes in the human hippocampus using high‐resolution (1.5 mm isotropic) blood‐oxygenation level‐dependent fMRI. Recent evidence from animal studies suggests that hyperactivity in the CA3 region of the hippocampus may underlie behavioral deficits in pattern separation in aged rats. Here, we report evidence that is consistent with findings from the animal studies. We found a behavioral impairment in pattern separation in a sample of healthy older adults compared with young controls. We also found a related increase in CA3/dentate gyrus activity levels during an fMRI contrast that stresses pattern separation abilities. In a detailed analysis of behavior, we also found that the pattern of impairment was consistent with the predictions of the animal model, where larger changes in the input (greater dissimilarity) were required in order for elderly adults to successfully encode new information as distinct from previously learned information. These findings are also consistent with recent fMRI and behavioral reports in healthy aging, and further suggest that a specific functional deficit in the CA3/dentate network contributes to memory difficulties with aging. © 2010 Wiley‐Liss, Inc. http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Hippocampus Wiley

Pattern separation deficits associated with increased hippocampal CA3 and dentate gyrus activity in nondemented older adults

Loading next page...
 
/lp/wiley/pattern-separation-deficits-associated-with-increased-hippocampal-ca3-608Z5EkrP7

References (72)

Publisher
Wiley
Copyright
Copyright © 2010 Wiley‐Liss, Inc.
ISSN
1050-9631
eISSN
1098-1063
DOI
10.1002/hipo.20808
pmid
20865732
Publisher site
See Article on Publisher Site

Abstract

There is widespread evidence that memory deteriorates with aging, however the exact mechanisms that underlie these changes are not well understood. Given the growing size of the aging population, there is an imperative to study age‐related neurocognitive changes in order to better parse healthy from pathological aging. Using a behavioral paradigm that taxes pattern separation (the ability to differentiate novel yet similar information from previously learned information and thus avoid interference), we investigated age‐related neural changes in the human hippocampus using high‐resolution (1.5 mm isotropic) blood‐oxygenation level‐dependent fMRI. Recent evidence from animal studies suggests that hyperactivity in the CA3 region of the hippocampus may underlie behavioral deficits in pattern separation in aged rats. Here, we report evidence that is consistent with findings from the animal studies. We found a behavioral impairment in pattern separation in a sample of healthy older adults compared with young controls. We also found a related increase in CA3/dentate gyrus activity levels during an fMRI contrast that stresses pattern separation abilities. In a detailed analysis of behavior, we also found that the pattern of impairment was consistent with the predictions of the animal model, where larger changes in the input (greater dissimilarity) were required in order for elderly adults to successfully encode new information as distinct from previously learned information. These findings are also consistent with recent fMRI and behavioral reports in healthy aging, and further suggest that a specific functional deficit in the CA3/dentate network contributes to memory difficulties with aging. © 2010 Wiley‐Liss, Inc.

Journal

HippocampusWiley

Published: Sep 1, 2011

There are no references for this article.