Figure 3.

Local perfusion of the injury site in vivo with semaphorin 3A reduces pain behaviors in the SNL model. Baseline behaviors (average of two measurements) are plotted on day 0. Immediately after the ligation and transection of the L5 spinal nerve, fine tubing was led from a 14 d osmotic pump to the cut end of the spinal nerve to deliver either vehicle or semaphorin 3A (16 µg/ml), as indicated by the shaded bar. a, Threshold for withdrawal responses to von Frey filaments (F_(1,10) = 137.58). b, Dynamic allodynia (withdrawal responses to light stroking with a fine cotton wisp; F_(1,10) = 91.08). c, Cold allodynia (withdrawal responses to a drop of acetone; F_(1,10) = 13.77). *p < 0.05; **p < 0.01; ***p < 0.001, significant difference between the two groups at the indicated time points, two-way repeated-measures ANOVA, with Bonferroni’s post-test). n = 6 male rats/group. PWT, paw withdrawal threshold.