Proteolytic regulation of synaptic plasticity in the mouse primary visual cortex: analysis of matrix metalloproteinase 9 deficient mice
| Autor: | Emily A. Kelly, Cassandra E. Lamantia, Amanda S Russo, Ania K. Majewska, Cory D Jackson |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Dendritic spine
primary visual cortex (V1) matrix metalloproteinase 9 (MMP9) Biology MMP9 spine ocular dominance lcsh:RC321-571 dendrite Extracellular matrix 03 medical and health sciences Cellular and Molecular Neuroscience 0302 clinical medicine Excitatory synapse Extracellular medicine Sensory cortex lcsh:Neurosciences. Biological psychiatry. Neuropsychiatry Original Research 030304 developmental biology 0303 health sciences primary sensory cortex (S1) body regions Monocular deprivation medicine.anatomical_structure plasticity Synaptic plasticity Neuroscience 030217 neurology & neurosurgery |
| Zdroj: | Frontiers in Cellular Neuroscience, Vol 9 (2015) Frontiers in Cellular Neuroscience |
| ISSN: | 1662-5102 |
| DOI: | 10.3389/fncel.2015.00369 |
| Popis: | The extracellular matrix (ECM) is known to play important roles in regulating neuronal recovery from injury. The ECM can also impact physiological synaptic plasticity, although this process is less well understood. To understand the impact of the ECM on synaptic function and remodeling in vivo, we examined ECM composition and proteolysis in a well-established model of experience-dependent plasticity in the visual cortex. We describe a rapid change in ECM protein composition during ocular dominance plasticity in adolescent mice, and a loss of ECM remodeling in mice that lack the extracellular protease, matrix metalloproteinase-9 (MMP9). Loss of MMP9 also attenuated functional ocular dominance plasticity following monocular deprivation and reduced excitatory synapse density and spine density in sensory cortex. While we observed no change in the morphology of existing dendritic spines, spine dynamics were altered, and MMP9 knock-out (KO) mice showed increased turnover of dendritic spines over a period of 2 days. We also analyzed the effects of MMP9 loss on microglia, as these cells are involved in extracellular remodeling and have been recently shown to be important for synaptic plasticity. MMP9 KO mice exhibited very limited changes in microglial morphology. Ultrastructural analysis, however, showed that the extracellular space surrounding microglia was increased, with concomitant increases in microglial inclusions, suggesting possible changes in microglial function in the absence of MMP9. Taken together, our results show that MMP9 contributes to ECM degradation, synaptic dynamics and sensory-evoked plasticity in the mouse visual cortex. |
| Databáze: | OpenAIRE |
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