Fig. 1.
Spared nerve injury (SNI) induces long-lasting mechanical and cold allodynia and increases immobility during forced swim tests in rats. (A) Animals that underwent SNI surgery developed mechanical allodynia that lasted at least 14 days. Mechanical allodynia was tested using von Frey filaments. In comparison, sham-treated rats (control) did not demonstrate mechanical allodynia. A 50% withdrawal threshold was calculated (see Methods for details). ****P < 0.0001, two-way ANOVA with repeated measures and post hoc Bonferroni multiple comparison tests. Sham group, n = 6. SNI group, n = 10 (B) SNI-treated animals, in contrast to control rats, developed cold allodynia that lasted at least 14 days. ****P < 0.0001, two-way ANOVA with repeated measures and post hoc Bonferroni multiple comparison tests. Sham group, n = 6. SNI group, n = 10 (C) SNI-treated rats demonstrated increased immobility during the forced swim test compared to controls. *P < 0.05, unpaired two-tailed Student test. Sham group, n = 12. SNI group, n = 10. (D) Locomotion was unaffected by SNI surgery. P > 0.05, two-way ANOVA with repeated measures and post hoc Bonferroni tests. n = 6 for both Sham and SNI groups. Error bars represent standard error mean (SEM).