Hippocampal activation is associated with longitudinal amyloid accumulation and cognitive decline

  1. Stephanie L Leal  Is a corresponding author
  2. Susan M Landau
  3. Rachel K Bell
  4. William J Jagust  Is a corresponding author
  1. University of California, Berkeley, United States

Abstract

The amyloid hypothesis suggests that beta-amyloid (Aβ) deposition leads to alterations in neural function and ultimately to cognitive decline in Alzheimer's disease. However, factors that underlie Aβ deposition are incompletely understood. One proposed model suggests that synaptic activity leads to increased Aβ deposition. More specifically, hyperactivity in the hippocampus may be detrimental and could be one factor that drives Aβ deposition. To test this model, we examined the relationship between hippocampal activity during a memory task using fMRI and subsequent longitudinal change in Aβ using PIB-PET imaging in cognitively normal older adults. We found that greater hippocampal activation at baseline was associated with increased Aβ accumulation. Furthermore, increasing Aβ accumulation mediated the influence of hippocampal activation on declining memory performance, demonstrating a crucial role of Aβ in linking hippocampal activation and memory. These findings support a model linking increased hippocampal activation to subsequent Aβ deposition and cognitive decline.

Article and author information

Author details

  1. Stephanie L Leal

    Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
    For correspondence
    stephanieleal@berkeley.edu
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-8082-8291
  2. Susan M Landau

    Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
    Competing interests
    The authors declare that no competing interests exist.
  3. Rachel K Bell

    Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
    Competing interests
    The authors declare that no competing interests exist.
  4. William J Jagust

    Helen Wills Neuroscience Institute, University of California, Berkeley, Berkeley, United States
    For correspondence
    jagust@berkeley.edu
    Competing interests
    The authors declare that no competing interests exist.

Funding

National Institute on Aging (AG054116)

  • Stephanie L Leal

National Institute on Aging (AG034570)

  • William J Jagust

The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.

Reviewing Editor

  1. Alison Goate, Icahn School of Medicine at Mount Sinai, United States

Ethics

Human subjects: Informed consent was obtained from all research participants and approved by the Institutional Review Boards of Lawrence Berkeley National Labs and UC Berkeley.

Version history

  1. Received: November 5, 2016
  2. Accepted: February 6, 2017
  3. Accepted Manuscript published: February 8, 2017 (version 1)
  4. Version of Record published: February 24, 2017 (version 2)

Copyright

© 2017, Leal et al.

This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.

Metrics

  • 3,396
    views
  • 646
    downloads
  • 84
    citations

Views, downloads and citations are aggregated across all versions of this paper published by eLife.

Download links

A two-part list of links to download the article, or parts of the article, in various formats.

Downloads (link to download the article as PDF)

Open citations (links to open the citations from this article in various online reference manager services)

Cite this article (links to download the citations from this article in formats compatible with various reference manager tools)

  1. Stephanie L Leal
  2. Susan M Landau
  3. Rachel K Bell
  4. William J Jagust
(2017)
Hippocampal activation is associated with longitudinal amyloid accumulation and cognitive decline
eLife 6:e22978.
https://doi.org/10.7554/eLife.22978

Share this article

https://doi.org/10.7554/eLife.22978

Further reading

    1. Genetics and Genomics
    2. Neuroscience
    Kenneth Chiou, Noah Snyder-Mackler
    Insight

    Single-cell RNA sequencing reveals the extent to which marmosets carry genetically distinct cells from their siblings.

    1. Neuroscience
    Flavio J Schmidig, Simon Ruch, Katharina Henke
    Research Article

    We are unresponsive during slow-wave sleep but continue monitoring external events for survival. Our brain wakens us when danger is imminent. If events are non-threatening, our brain might store them for later consideration to improve decision-making. To test this hypothesis, we examined whether novel vocabulary consisting of simultaneously played pseudowords and translation words are encoded/stored during sleep, and which neural-electrical events facilitate encoding/storage. An algorithm for brain-state-dependent stimulation selectively targeted word pairs to slow-wave peaks or troughs. Retrieval tests were given 12 and 36 hr later. These tests required decisions regarding the semantic category of previously sleep-played pseudowords. The sleep-played vocabulary influenced awake decision-making 36 hr later, if targeted to troughs. The words’ linguistic processing raised neural complexity. The words’ semantic-associative encoding was supported by increased theta power during the ensuing peak. Fast-spindle power ramped up during a second peak likely aiding consolidation. Hence, new vocabulary played during slow-wave sleep was stored and influenced decision-making days later.