Fig. 4.

The SNI condition produced mechanical allodynia 11 days after surgery. Time 0 represents mechanosensitivity results on day 11 before treatment. Results of a baseline measurement before surgery demonstrated no significant difference between groups (data not shown, average baseline before surgery for all groups was 4.3 ± 1.10 g f). Panel A: The experimental paradigm comprised once-daily treatment of three days and mechanosensitivity testing before daily treatment. Panel B: (2R,6R)-HNK reversed mechanical allodynia associated with the neuropathic pain condition within 4 hours of treatment, and the effect persisted for at least 24 hours. Repeat dosing did not appear to lessen the pain reduction-like effect. Gabapentin reversed mechanical allodynia 4 hours following treatment but did not produce a significant effect 24 hours following the first or third treatment. Vertical bars represent the group means ± S.D. Drug doses are compared with saline at the same time point, **P < 0.01, ***P < 0.001, ****P < 0.0001, N = 9-10 (N = 9 for saline and gabapentin 30 mg/kg groups, N = 10 for all other groups).