Inset: experimental paradigm. The MMP biomarker, dye-quenched gelatin (2 mg/ml), was delivered i.c. via cannula at the initiation of LRx. (A) The biomarker reveals punctate staining, and a significant increase in density and intensity following LRx (n=6, 6, 8 subjects for Con, DE, LRx, respectively). One-way ANOVA, F=9.2; p=0.002 for intensity, F=27.74; p<0.0001 for density, F=10.17, p=0.0014 for size; *p<0.05, Tukey-Kramer post hoc. (B) Double labeled confocal micrographs of control, DE and LRx visual cortex labeled with MMP biomarker (green) and marker for cortical axons (top: VGluT1; red) or thalamic axons (bottom: VGluT2; red). Scale bars: 20 μm (insets: 5 μm). Co-localization with VGluT2, but not VGluT1, is significantly increased by LRx. One-way ANOVA, F=0.95, p=0.41 for VGluT1 (n=6, 6, 7 subjects for Con, DE, LRx, respectively). F=16.16, p=0.0003 for VGluT2 (n=5, 5, 6 subjects for Con, DE, LRx, respectively). *p<0.05, Tukey-Kramer post hoc. (C) Increase in co-localization of MMP biomarker/VGluT2 with PV+ and PV- immunoreactive puncta following LRx (n=4 subjects each for Con and LRx). *p<0.005, Student’s T-test. All quantifications were performed 250 – 400 μm from the cortical surface in V1b.