Intrinsic connectivity reveals functionally distinct cortico-hippocampal networks in the human brain

Abstract

Episodic memory depends on interactions between the hippocampus and interconnected neocortical regions. Here, using data-driven analyses of resting-state functional magnetic resonance imaging (fMRI) data, we identified the networks that interact with the hippocampus—the default mode network (DMN) and a “medial temporal network” (MTN) that included regions in the medial temporal lobe (MTL) and precuneus. We observed that the MTN plays a critical role in connecting the visual network to the DMN and hippocampus. The DMN could be further divided into 3 subnetworks: a “posterior medial” (PM) subnetwork comprised of posterior cingulate and lateral parietal cortices; an “anterior temporal” (AT) subnetwork comprised of regions in the temporopolar and dorsomedial prefrontal cortex; and a “medial prefrontal” (MP) subnetwork comprised of regions primarily in the medial prefrontal cortex (mPFC). These networks vary in their functional connectivity (FC) along the hippocampal long axis and represent different kinds of information during memory-guided decision-making. Finally, a Neurosynth meta-analysis of fMRI studies suggests new hypotheses regarding the functions of the MTN and DMN subnetworks, providing a framework to guide future research on the neural architecture of episodic memory.

Document Details

Document Type
Pub Defense Publication
Publication Date
Jun 02, 2021
Source ID
10.1371/journal.pbio.3001275

Entities

People

  • Alexander Barnett
  • Charan Ranganath
  • Eda Mizrak
  • Halle R Zucker
  • Walter Reilly
  • Zachariah M Reagh

Organizations

  • National Institute on Aging
  • National Science Foundation
  • Natural Sciences and Engineering Research Council
  • Office of Naval Research

Tags

Fields of Study

  • Biology

Readers

  • Computer Networking
  • Neuroscience