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Tau deposition is associated with functional isolation of the hippocampus in aging.

ABSTRACT: The tau protein aggregates in aging and Alzheimer disease and may lead to memory loss through disruption of medial temporal lobe (MTL)-dependent memory systems. Here, we investigated tau-mediated mechanisms of hippocampal dysfunction that underlie the expression of episodic memory decline using fMRI measures of hippocampal local coherence (regional homogeneity; ReHo), distant functional connectivity and tau-PET. We show that age and tau pathology are related to higher hippocampal ReHo. Functional disconnection between the hippocampus and other components of the MTL memory system, particularly an anterior-temporal network specialized for object memory, is also associated with higher hippocampal ReHo and greater tau burden in anterior-temporal regions. These associations are not observed in the posteromedial network, specialized for context/spatial information. Higher hippocampal ReHo predicts worse memory performance. These findings suggest that tau pathology plays a role in disconnecting the hippocampus from specific MTL memory systems leading to increased local coherence and memory decline.

SUBMITTER: Harrison TM

PROVIDER: S-EPMC6814780 | biostudies-literature | 2019 Oct

REPOSITORIES: biostudies-literature

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Tau deposition is associated with functional isolation of the hippocampus in aging.

Harrison Theresa M TM Maass Anne A Adams Jenna N JN Du Richard R Baker Suzanne L SL Jagust William J WJ

Nature communications 20191025 1

The tau protein aggregates in aging and Alzheimer disease and may lead to memory loss through disruption of medial temporal lobe (MTL)-dependent memory systems. Here, we investigated tau-mediated mechanisms of hippocampal dysfunction that underlie the expression of episodic memory decline using fMRI measures of hippocampal local coherence (regional homogeneity; ReHo), distant functional connectivity and tau-PET. We show that age and tau pathology are related to higher hippocampal ReHo. Functiona ...[more]

PMID: 31653847

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Tau deposition is associated with functional isolation of the hippocampus in aging.

Publications

Tau deposition is associated with functional isolation of the hippocampus in aging.

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