PreprintCited by 107Memory and Neural MechanismsNeuroscience and Neuropharmacology ResearchProtease and Inhibitor Mechanisms

The extracellular protease matrix metalloproteinase-9 is activated by inhibitory avoidance learning and required for long-term memory

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Nagy, Vanja, Bozdagi, Ozlem, Huntley, George W.·2007·Learning & Memory

Abstract

Matrix metalloproteinases (MMPs) are a family of extracellularly acting proteolytic enzymes with well-recognized roles in plasticity and remodeling of synaptic circuits during brain development and following brain injury. However, it is now becoming increasingly apparent that MMPs also function in normal, nonpathological synaptic plasticity of the kind that may underlie learning and memory. Here, we extend this idea by investigating the role and regulation of MMP-9 in an inhibitory avoidance (IA) learning and memory task. We demonstrate that following IA training, protein levels and proteolytic activity of MMP-9 become elevated in hippocampus by 6 h, peak at 12-24 h, then decline to baseline values by approximately 72 h. When MMP function is abrogated by intrahippocampal infusion of a potent gelatinase (MMP-2 and MMP-9) inhibitor 3.5 h following IA training, a time prior to the onset of training-induced elevation in levels, IA memory retention is significantly diminished when tested 1-3 d later. Animals impaired at 3 d exhibit robust IA memory when retrained, suggesting that such impairment is not likely attributed to toxic or other deleterious effects that permanently disrupt hippocampal function. In anesthetized adult rats, the effective distance over which synaptic plasticity is impaired by a single intrahippocampal infusion of the MMP inhibitor of the kind that blocks IA memory is approximately 1200 microm. Taken together, these data suggest that IA training induces a slowly emerging, but subsequently protracted period of MMP-mediated proteolysis critical for enabling long-lasting synaptic modification that underlies long-term memory consolidation.

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Authors
Nagy, V., Bozdagi, O., & Huntley, G. W.
Affiliations
Icahn School of Medicine at Mount Sinai (US)
Venue
Learning & Memory
Published
2007-09-25
Volume
14
Issue
10
Pages
655-664
ISSN
  • 1072-0502 (ISSN-L)
  • 1549-5485
OpenAlex
W2119591418
Cited by
107
References
91
Citations by year
2026: 2 · 2025: 2 · 2024: 2 · 2023: 7 · 2022: 4 · 2021: 4 · 2020: 6 · 2019: 10 · 2018: 3 · 2017: 9 · 2016: 3 · 2015: 9 · 2014: 5 · 2013: 8 · 2012: 10
Type
posted content
Language
en
Open access
Locations
  • Learning & Memory (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
Funders
  • U.S. Public Health Service
  • National Institute of Mental Health (R01MH075783, MH075783-01)
Topics
  • Life Sciences › Neuroscience › Cognitive Neuroscience › Memory and Neural Mechanisms
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neuropharmacology Research
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Cancer Research › Protease and Inhibitor Mechanisms
Keywords
MMP-9, passive avoidance learning, long-term memory consolidation, hippocampus, synaptic plasticity, matrix metalloproteinase inhibition, gelatinase inhibitors, extracellular proteolysis, memory impairment
MeSH terms
Animals, Avoidance Learning, Electroshock, Enzyme Induction, Hippocampus, Male, Nerve Tissue Proteins, Reaction Time, Retention, Psychology, Time Factors, Rats, Sprague-Dawley, Long-Term Potentiation, Rats, Long-Evans, Matrix Metalloproteinase 9, Rats, Matrix Metalloproteinase Inhibitors

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