Hippocampal ensemble dynamics timestamp events in long-term memory

  1. Alon Rubin
  2. Nitzan Geva
  3. Liron Sheintuch
  4. Yaniv Ziv  Is a corresponding author
  1. Weizmann Institute of Science, Israel

Abstract

The capacity to remember temporal relationships between different events is essential to episodic memory, but little is currently known about its underlying mechanisms. We performed time-lapse imaging of thousands of neurons over weeks in the hippocampal CA1 of mice as they repeatedly visited two distinct environments. Longitudinal analysis exposed ongoing environment-independent evolution of episodic representations, despite stable place field locations and constant remapping between the two environments. These dynamics time-stamped experienced events via neuronal ensembles that had cellular composition and activity patterns unique to specific points in time. Temporally close episodes shared a common timestamp regardless of the spatial context in which they occurred. Temporally remote episodes had distinct timestamps, even if they occurred within the same spatial context. Our results suggest that days-scale hippocampal ensemble dynamics could support the formation of a mental timeline in which experienced events could be mnemonically associated or dissociated based on their temporal distance.

Article and author information

Author details

  1. Alon Rubin

    Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
    Competing interests
    No competing interests declared.
  2. Nitzan Geva

    Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
    Competing interests
    No competing interests declared.
  3. Liron Sheintuch

    Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
    Competing interests
    No competing interests declared.
  4. Yaniv Ziv

    Department of Neurobiology, Weizmann Institute of Science, Rehovot, Israel
    For correspondence
    yaniv.ziv@weizmann.ac.il
    Competing interests
    Yaniv Ziv, Has ownership interests at Inscopix Inc.

Ethics

Animal experimentation: All animal work was approved by the Weizmann Institute institutional animal care and use committee (IACUC protocol 18030515-3).

Reviewing Editor

  1. Howard Eichenbaum, Boston University, United States

Publication history

  1. Received: October 12, 2015
  2. Accepted: December 17, 2015
  3. Accepted Manuscript published: December 18, 2015 (version 1)
  4. Version of Record published: January 28, 2016 (version 2)

Copyright

© 2015, Rubin 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.

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  1. Alon Rubin
  2. Nitzan Geva
  3. Liron Sheintuch
  4. Yaniv Ziv
(2015)
Hippocampal ensemble dynamics timestamp events in long-term memory
eLife 4:e12247.
https://doi.org/10.7554/eLife.12247
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