Effect of the TrkA-Fc chimera on the analgesic effect of ropivacaine in CCI rats. The latencies for paw withdrawal on the ipsilateral (left panel) and contralateral (right panel) sides in response to thermal stimuli in CCI rats were evaluated. Ropivacaine and the TrkA-Fc chimera (open circles) or control IgG1-Fc protein (closed circles) were epidurally administered once daily from days 7 to 9, as indicated by the horizontal bars. **p < 0.01 compared with the values in CCI rats treated with the IgG1-Fc protein on the corresponding days by an unpaired t-test (n = 5). ##
p < 0.01 and ###
p < 0.001 compared with the values on the preoperative day by Dunnett's multiple comparison test (n = 5).