Figure 2

Differences in withdrawal latency between left and right hind paws after thermal (A) and mechanical (B) stimulation. There are no significant differences in withdrawal latencies between hindpaws in the sham group (S). Spinal nerve ligation (group L) produced a significant difference in withdrawal latencies between hindpaws. Intra-peritoneal amitriptyline post-injury (group A) alleviated thermal hypersensitivity for one week. Pretreatment intrathecal amitriptyline in combination with post-injury intra-peritoneal amitriptyline (group P) alleviated thermal hypersensitivity for 2 weeks and attenuated mechanical hypersensitivity for 1 week. POD: postoperative day, (red accent diamond: group S, red down-pointing triangle: group L, green circle: group A, olive green square: group P, n = 24/group, 4-5/each time point). L vs. S, ☆: P < 0.001; A vs. L, c: P < 0.001; P vs. L,#: P < 0.001. Group differences were compared by ANOVA followed by Scheffe test of multiple post hoc analyses. Error bars represent SE.