Brain Structure and Function

, Volume 220, Issue 5, pp 2675–2689

Altered neuronal architecture and plasticity in the visual cortex of adult MMP-3-deficient mice

Authors

  • Jeroen Aerts
    • Laboratory of Neuroplasticity and NeuroproteomicsKU Leuven
  • Julie Nys
    • Laboratory of Neuroplasticity and NeuroproteomicsKU Leuven
  • Lieve Moons
    • Laboratory of Neural Circuit Development and RegenerationKU Leuven
  • Tjing-Tjing Hu
    • Laboratory of Neuroplasticity and NeuroproteomicsKU Leuven
    • Laboratory of Neural Circuit Development and RegenerationKU Leuven
    • Laboratory of Neuroplasticity and NeuroproteomicsKU Leuven
Original Article

DOI: 10.1007/s00429-014-0819-4

Cite this article as:
Aerts, J., Nys, J., Moons, L. et al. Brain Struct Funct (2015) 220: 2675. doi:10.1007/s00429-014-0819-4

Abstract

Matrix metalloproteinases (MMPs) are Zn2+-dependent endopeptidases considered to be essential for normal brain development and neuroplasticity by modulating extracellular matrix proteins, receptors, adhesion molecules, growth factors and cytoskeletal proteins. Specifically, MMP-3 has recently been implicated in synaptic plasticity, hippocampus-dependent learning and neuronal development and migration in the cerebellum. However, the function(s) of this enzyme in the neocortex is understudied. Therefore, we explored the phenotypical characteristics of the neuronal architecture and the capacity for experience-dependent cortical plasticity in the visual cortex of adult MMP-3-deficient (MMP-3−/−) mice. Golgi–Cox stainings revealed a significant reduction in apical dendritic length and an increased number of apical obliques for layer V pyramidal neurons in the visual cortex of adult MMP-3−/− mice compared to wild-type (WT) animals. In addition, a significant upregulation of both phosphorylated and non-phosphorylated neurofilament protein (NF)-high, phosphorylated NF-medium, NF-low and α-internexin was detected in the visual cortex of MMP-3−/− mice. To assess the effect of MMP-3 deficiency on cortical plasticity, we monocularly enucleated adult MMP-3−/− mice and analyzed the reactivation of the contralateral visual cortex 7 weeks post-enucleation. In contrast to previous results in C57Bl/6J adult mice, activity remained confined to the binocular zone and did not expand into the monocular regions indicative for an aberrant open-eye potentiation. Permanent hypoactivity in the monocular cortex lateral and medial to V1 also indicated a lack of cross-modal plasticity. These observations demonstrate that genetic inactivation of MMP-3 has profound effects on the structural integrity and plasticity response of the visual cortex of adult mice.

Keywords

Matrix metalloproteinaseGolgi–CoxApical dendriteNeurofilamentMonocular enucleationMultimodal

Copyright information

© Springer-Verlag Berlin Heidelberg 2014