1. Neuroscience

Imaging a memory trace over half a life-time in the medial temporal lobe reveals a time-limited role of CA3 neurons in retrieval

  1. Vanessa Lux
  2. Erika Atucha
  3. Takashi Kitsukawa
  4. Magdalena M Sauvage  Is a corresponding author
  1. Ruhr University Bochum, Germany
  2. Osaka University, Japan
https://doi.org/10.7554/eLife.11862
Share this article
Cite this article
  1. Vanessa Lux
  2. Erika Atucha
  3. Takashi Kitsukawa
  4. Magdalena M Sauvage
(2016)
Imaging a memory trace over half a life-time in the medial temporal lobe reveals a time-limited role of CA3 neurons in retrieval
eLife 5:e11862.
https://doi.org/10.7554/eLife.11862
  2. Download BibTeX
  3. Download .RIS

Abstract

Whether retrieval still depends on the hippocampus as memories age or relies then on cortical areas remains a major controversy. Despite evidence for a functional segregation between CA1, CA3 and parahippocampal areas, their specific role within this frame is unclear. Especially, the contribution of CA3 is questionable as very remote memories might be too degraded to be used for pattern completion. To identify the specific role of these areas, we imaged brain activity in mice during retrieval of recent, early remote and very remote fear memories by detecting the immediate-early gene Arc. Investigating correlates of the memory trace over an extended period allowed us to report that, in contrast to CA1, CA3 is no longer recruited in very remote retrieval. Conversely, we showed that parahippocampal areas are then maximally engaged. These results suggest a shift from a greater contribution of the trisynaptic loop to the temporoammonic pathway for retrieval.

Article and author information

Author details

  1. Vanessa Lux

    Functional Architecture of Memory unit, Mercator Research Group, Medical Faculty, Ruhr University Bochum, Bochum, Germany
    Competing interests
    The authors declare that no competing interests exist.

  2. Erika Atucha

    Functional Architecture of Memory unit, Mercator Research Group, Medical Faculty, Ruhr University Bochum, Bochum, Germany
    Competing interests
    The authors declare that no competing interests exist.

  3. Takashi Kitsukawa

    Graduate School of Frontier Biosciences, Osaka University, Osaka, Japan
    Competing interests
    The authors declare that no competing interests exist.

  4. Magdalena M Sauvage

    Functional Architecture of Memory unit, Mercator Research Group, Medical Faculty, Ruhr University Bochum, Bochum, Germany
    For correspondence
    magdalena.sauvage@gmail.com
    Competing interests
    The authors declare that no competing interests exist.

Reviewing Editor

  1. Upinder S Bhalla, National Centre for Biological Sciences, India

Ethics

Animal experimentation: All procedures were approved by the Ruhr-Universität Bochum Institutional Animal Use Committee and the LANUV (8.87-51.04.20.09.323)

Version history

  1. Received: September 24, 2015
  2. Accepted: February 9, 2016
  3. Accepted Manuscript published: February 12, 2016 (version 1)
  4. Version of Record published: March 15, 2016 (version 2)

Copyright

© 2016, Lux 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

  • 2,719
    views
  • 725
    downloads
  • 25
    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. Vanessa Lux
  2. Erika Atucha
  3. Takashi Kitsukawa
  4. Magdalena M Sauvage
(2016)
Imaging a memory trace over half a life-time in the medial temporal lobe reveals a time-limited role of CA3 neurons in retrieval
eLife 5:e11862.
https://doi.org/10.7554/eLife.11862

Share this article

https://doi.org/10.7554/eLife.11862

Categories and tags

Research organism

Further reading

    1. Cell Biology
    2. Neuroscience

    Translational regulation enhances distinction of cell types in the nervous system

    Toshiharu Ichinose, Shu Kondo ... Hiromu Tanimoto
    Research Article

    Multicellular organisms are composed of specialized cell types with distinct proteomes. While recent advances in single-cell transcriptome analyses have revealed differential expression of mRNAs, cellular diversity in translational profiles remains underinvestigated. By performing RNA-seq and Ribo-seq in genetically defined cells in the Drosophila brain, we here revealed substantial post-transcriptional regulations that augment the cell-type distinctions at the level of protein expression. Specifically, we found that translational efficiency of proteins fundamental to neuronal functions, such as ion channels and neurotransmitter receptors, was maintained low in glia, leading to their preferential translation in neurons. Notably, distribution of ribosome footprints on these mRNAs exhibited a remarkable bias toward the 5′ leaders in glia. Using transgenic reporter strains, we provide evidence that the small upstream open-reading frames in the 5’ leader confer selective translational suppression in glia. Overall, these findings underscore the profound impact of translational regulation in shaping the proteomics for cell-type distinction and provide new insights into the molecular mechanisms driving cell-type diversity.

    1. Neuroscience

    Differential functions of the dorsal and intermediate regions of the hippocampus for optimal goal-directed navigation in VR space

    Hyeri Hwang, Seung-Woo Jin, Inah Lee
    Research Article

    Goal-directed navigation requires the hippocampus to process spatial information in a value-dependent manner, but its underlying mechanism needs to be better understood. Here, we investigated whether the dorsal (dHP) and intermediate (iHP) regions of the hippocampus differentially function in processing place and its associated value information. Rats were trained in a place-preference task involving reward zones with different values in a visually rich virtual reality environment where two-dimensional navigation was possible. Rats learned to use distal visual scenes effectively to navigate to the reward zone associated with a higher reward. Inactivation of both dHP and iHP with muscimol altered the efficiency and precision of wayfinding behavior, but iHP inactivation induced more severe damage, including impaired place preference. Our findings suggest that the iHP is more critical for value-dependent navigation toward higher-value goal locations.

    1. Neuroscience

    Neural Plasticity: Restoring cerebellar-dependent learning

    Jessica L Verpeut
    Insight

    Behavioral and pharmaceutical interventions reverse defects associated with increased cerebellar long-term depression in a mouse model of Fragile X syndrome.