Skin/Muscle Incision and Retraction Induces Evoked and Spontaneous Pain in Mice

Figure 2

Paw withdrawal threshold (PWT) for mechanical stimulation and paw withdrawal latencies (PWLs) to noxious heat stimulation evoked by skin/muscle incision and retraction (SMIR) surgery. (a) The sham treatment group did not demonstrate significant mechanical hypersensitivity as compared to baseline, to von Frey stimulation in the ipsilateral paw. SMIR surgery evoked a persistent significant mechanical hypersensitivity. SMIR-evoked mechanical hypersensitivity in the ipsilateral paw (two-way RM ANOVA, sham versus SMIR: F1; 16 = 50.6, ; time: F6; 96 = 15.42, , interaction: F6; 96 = 15.48, ; n = 9 for the sham group, n = 9 for the SMIR group; , under Sidak’s multiple comparisons test). (b) Paw withdrawal latencies in the sham-operated group were unaltered throughout the time course. SMIR surgery also did not evoke significant heat hypersensitivity. Withdrawal latencies of the ipsilateral paws in the SMIR-operated mice were not significantly altered up to postoperative day 18 (two-way RM ANOVA, sham versus SMIR: F1; 17 = 0.013, ; time: F6; 102 = 0.07, , interaction: F6; 102 = 0.23, ; n = 9 for the sham group, n = 10 for the SMIR group, under Sidak’s multiple comparisons test). ANOVA, analysis of variance; RM, repeated measures; BL, presurgery baseline.

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