1. Neuroscience
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Light reintroduction after dark exposure reactivates plasticity in adults via perisynaptic activation of MMP-9

  1. Sachiko Murase  Is a corresponding author
  2. Crystal Lantz
  3. Elizabeth Quinlan  Is a corresponding author
  1. University of Maryland, United States
Research Article
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Cite this article as: eLife 2017;6:e27345 doi: 10.7554/eLife.27345


The sensitivity of ocular dominance to regulation by monocular deprivation is the canonical model of plasticity confined to a critical period. However, we have previously shown that visual deprivation through dark exposure (DE) reactivates critical period plasticity in adults. Previous work assumed that the elimination of visual input was sufficient to enhance plasticity in the adult mouse visual cortex. In contrast, here we show that light reintroduction (LRx) after DE is responsible for the reactivation of plasticity. LRx triggers degradation of the ECM, which is blocked by pharmacological inhibition or genetic ablation of matrix metalloproteinase-9 (MMP-9). LRx induces an increase in MMP-9 activity that is perisynaptic and enriched at thalamo-cortical synapses. The reactivation of plasticity by LRx is absent in Mmp9-/- mice, and is rescued by hyaluronidase, an enzyme that degrades core ECM components. The LRx-induced increase in MMP-9 removes constraints on structural and functional plasticity in the mature cortex.

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Author details

  1. Sachiko Murase

    Department of Biology, University of Maryland, College Park, United States
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
  2. Crystal Lantz

    Department of Biology, University of Maryland, College Park, United States
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0002-9763-4725
  3. Elizabeth Quinlan

    Department of Biology, University of Maryland, College Park, United States
    For correspondence
    Competing interests
    The authors declare that no competing interests exist.
    ORCID icon "This ORCID iD identifies the author of this article:" 0000-0003-3496-6607


National Eye Institute (R01)

  • Elizabeth Quinlan

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


Animal experimentation: All procedures, under Quinlan lab protocol R-16-30, conformed to the guidelines of the University of Maryland Institutional Animal Care and Use Committee and the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health.

Reviewing Editor

  1. Sacha B Nelson, Brandeis University, United States

Publication history

  1. Received: March 31, 2017
  2. Accepted: September 5, 2017
  3. Accepted Manuscript published: September 6, 2017 (version 1)
  4. Version of Record published: October 6, 2017 (version 2)


© 2017, Murase 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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