Figure 4
Dissociation of time course of mechanical allodynia and dynamic weight bearing (gait) changes following SNI injury. Data are combined from 22 inbred mouse strains (see text). Symbols represent mean ± S.E.M. 50% withdrawal threshold from von Frey filaments (g; in A), and mean ± S.E.M. CatWalk gait parameters including: (B) mean paw print intensity (arbitrary scale from 0-250), (C) stance phase duration (s), (D) paw print area (mm2), (E) paw placement ratio (ipsilateral: contralateral), and (F) regularity index (arbitrary scale from 0-100). For definitions see main text. In all graphs, data from the ipsilateral hindpaw is shown using closed symbols and solid lines; where relevant, data from the contralateral hindpaw is shown using open symbols and dashed lines. No significant changes in forepaw parameters were seen (data not shown). Note that mechanical allodynia peaks at post-operative day 4 and remains statistically unchanged thereafter, whereas CatWalk gait parameters display maximal changes at post operative day 1 and then partially recover. Individual significance levels are not shown for clarity; owing to the very large sample size (n = 122) all statements above are supported at p < 0.001 by repeated measures ANOVA.