Low-frequency oscillations in default mode subnetworks are associated with episodic memory impairments in Alzheimer's disease

Michele Veldsman, Natalia Egorova, Baljeet Singh, Dan M Mungas, Charles DeCarli, Amy Brodtmann

Research output: Contribution to journalArticle

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Abstract

Disruptions to functional connectivity in subsystems of the default mode network are evident in Alzheimer's disease (AD). Functional connectivity estimates correlations in the time course of low-frequency activity. Much less is known about other potential perturbations to this activity, such as changes in the amplitude of oscillations and how this relates to cognition. We examined the amplitude of low-frequency fluctuations in 44 AD patients and 128 cognitively normal participants and related this to episodic memory, the core deficit in AD. We show higher amplitudes of low-frequency oscillations in AD patients. Rather than being compensatory, this appears to be maladaptive, with greater amplitude in the ventral default mode subnetwork associated with poorer episodic memory. Perturbations to default mode subnetworks in AD are evident in the amplitude of low-frequency oscillations in the resting brain. These disruptions are associated with episodic memory demonstrating their behavioral and clinical relevance in AD.

Original languageEnglish (US)
Pages (from-to)98-106
Number of pages9
JournalNeurobiology of Aging
Volume59
DOIs
StatePublished - Nov 1 2017

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Keywords

  • Alzheimer's disease
  • Default mode network
  • Episodic memory

ASJC Scopus subject areas

  • Neuroscience(all)
  • Aging
  • Developmental Biology
  • Geriatrics and Gerontology
  • Clinical Neurology

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