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Updated: Sep 30, 2025
Monocular Visual Deprivation and Ocular Dominance Plasticity Measurement in the Mouse Primary Visual Cortex
Published on: February 8, 2020
Chronic Monocular Deprivation Reveals MMP9-Dependent and -Independent Aspects of Murine Visual System Plasticity
Sachiko Murase1, Sarah E Robertson2, Crystal L Lantz1
1Department of Biology and Neuroscience and Cognitive Sciences Program, University of Maryland, College Park, MD 20740, USA.
Abstract:
The deletion of matrix metalloproteinase MMP9 is combined here with chronic monocular deprivation (cMD) to identify the contributions of this proteinase to plasticity in the visual system. Calcium imaging of supragranular neurons of the binocular region of primary visual cortex (V1b) of wild-type mice revealed that cMD initiated at eye opening significantly decreased the strength of deprived-eye visual responses to all stimulus contrasts and spatial frequencies. cMD did not change the selectivity of V1b neurons for the spatial frequency, but orientation selectivity was higher in low spatial frequency-tuned neurons, and orientation and direction selectivity were lower in high spatial frequency-tuned neurons. Constitutive deletion of MMP9 did not impact the stimulus selectivity of V1b neurons, including ocular preference and tuning for spatial frequency, orientation, and direction. However, MMP9-/- mice were completely insensitive to plasticity engaged by cMD, such that the strength of the visual responses evoked by deprived-eye stimulation was maintained across all stimulus contrasts, orientations, directions, and spatial frequencies. Other forms of experience-dependent plasticity, including stimulus selective response potentiation, were normal in MMP9-/- mice. Thus, MMP9 activity is dispensable for many forms of activity-dependent plasticity in the mouse visual system, but is obligatory for the plasticity engaged by cMD.
Insights
Matrix metalloproteinase MMP9 is essential for visual system plasticity induced by chronic monocular deprivation (cMD) in mice. MMP9 deletion prevents cMD-driven changes in visual responses, highlighting MMP9
Area of Science:
- Neuroscience
- Molecular Biology
- Ophthalmology
Background:
- Visual system plasticity is crucial for developing normal vision.
- Matrix metalloproteinase 9 (MMP9) is implicated in various biological processes, including neural plasticity.
- Chronic monocular deprivation (cMD) is a standard model for studying visual cortex development and plasticity.
Purpose of the Study:
- To investigate the role of MMP9 in visual system plasticity.
- To determine if MMP9 is required for the effects of cMD on visual cortex development.
- To elucidate the specific contributions of MMP9 to experience-dependent visual processing.
Main Methods:
- Utilized calcium imaging in the primary visual cortex (V1b) of wild-type and MMP9 knockout (MMP9-/-) mice.
- Applied chronic monocular deprivation (cMD) starting at eye opening.
- Analyzed neuronal responses to various visual stimuli, including different contrasts, spatial frequencies, orientations, and directions.
Main Results:
- cMD in wild-type mice significantly reduced visual response strength and altered selectivity for orientation and direction.
- MMP9 deletion did not affect baseline visual stimulus selectivity in V1b neurons.
- MMP9-/- mice showed complete insensitivity to cMD-induced plasticity, maintaining normal visual response strength.
- Other forms of experience-dependent plasticity were unaffected in MMP9-/- mice.
Conclusions:
- MMP9 activity is dispensable for normal visual system development and various forms of plasticity.
- MMP9 is obligatory for the plasticity induced by chronic monocular deprivation in the visual cortex.
- Targeting MMP9 may offer therapeutic avenues for visual developmental disorders.
