An Integrated Index: Engrams, Place Cells, and Hippocampal Memory

Neuron. 2020 Sep 9;107(5):805-820. doi: 10.1016/j.neuron.2020.07.011. Epub 2020 Aug 6.

Abstract

The hippocampus and its extended network contribute to encoding and recall of episodic experiences. Drawing from recent anatomical, physiological, and behavioral studies, we propose that hippocampal engrams function as indices to mediate memory recall. We broaden this idea to discuss potential relationships between engrams and hippocampal place cells, as well as the molecular, cellular, physiological, and circuit determinants of engrams that permit flexible routing of information to intra- and extrahippocampal circuits for reinstatement, a feature critical to memory indexing. Incorporating indexing into frameworks of memory function opens new avenues of study and even therapies for hippocampal dysfunction.

Keywords: engram; hippocampus; index; learning and memory; place cell; reinstatement.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Hippocampus / physiology*
  • Humans
  • Mental Recall / physiology*
  • Place Cells / physiology*