VFX stimulates increased dendritic arbor and PSD-95 levels in WT but not MMP-9-null mice. A, Representative images from Golgi-stained cortex for mouse strains and treatment groups. B, C, Normalized branching data for primary, secondary, and tertiary processes. D-G, Results from PSD-95 quantification in hippocampal lysates. B, C, VFX significantly increases the number of secondary dendrites in WT but not MMP-9-null mice (n = 39-45 neurons from 6-8 mice per group, WT control vs VFX: p = 0.0176, Student's t test; MMP-9-null control vs VFX: not significant). D–G, VFX significantly increased PSD-95 levels in WT mice (p = 0.0388, Student's t test). There was, however, no significant difference in PSD-95 levels between the saline and VFX-treated MMP-9 KOs. Scale bar, 20 μm. *p < 0.05, n.s., non significant.