Figure 5: Correlation between brain tissue mechanics, gliosis, and ECM changes at 9 days PI.

Cf. Supplementary Fig. 4 for a later time point. (a) Rainbow-pallet map showing the relative difference in elastic modulus between injured and uninjured cortical hemisphere. Scale bar, 500 μm. The panels in the bottom rows represent vertical projection profiles (mean±s.d.) of the changes in elasticity determined for the regions i and ii indicated by dashed lines in the map . (b,c) The normalized and down-scaled pixel intensity image of vimentin and GFAP expression. The panels in the bottom rows represent vertical projection profiles (mean±s.d.) of the vimentin and GFAP normalized intensity estimated for the regions i and ii indicated by dashed lines in their respective images. (d,e) The normalized and down-scaled pixel intensity image of collagen IV and laminin expression. The panels in the bottom row represent vertical projection profiles (mean±s.d.) of the collagen and laminin normalized intensity in region i of their respective fluorescence images. In (a–e), grey arrows indicate the direct positive correlation between a drop in elasticity and an increase in protein expression. A positive correlation between tissue softening and vimentin and GFAP expression was also observed in regions located far away from the injury site medial to the scar (white arrows). (f) Shown are the calculated linear correlation coefficients for regions i and ii as well as the 2D correlation coefficients derived by linearly correlating the 2D matrix of the change in elasticity and the 2D maps of fluorescence intensity for each marker. (g) Average (mean±s.d.) correlation coefficients of three brains at 9, 21 and 22 days PI as a function of protein type and correlation region.