Ipsilateral but not contralateral mechanical allodynia in CD-1 mice given CCI (red). No significant changes from baseline von Frey thresholds were seen in either hind paw after sham surgery (blue) or simple repeated testing in unoperated mice (green). Symbols represent mean ± S.E.M. withdrawal threshold (average of two determinations per hind paw) from a nylon filament applying slowly increasing force (Ugo Basile Dynamic Plantar Aesthesiometer) to the plantar surface of the hind paws, measured before surgery (baseline; BL), and 1, 7, 14 and 28 days postoperatively. *p < 0.05 compared to baseline and contralateral side; ***p < 0.001 compared to baseline and contralateral side.