Disruption of persistent nociceptive behavior by cycloheximide.

<p><b>A</b>, <b>C</b>) Thermal hyperalgesia (A) and mechanical allodynia (C) were developed on the ipsilateral hind paw of the rats with ankle inflammation when tested over a 5-day period (designated as day -1 to -5). The statistical significance (ANOVA, P< 0.05; compared to the baseline) was not marked in the figure for the first five days in order to simplify the presentation. Subsequently, rats treated with cycloheximide showed a swift recovery of both thermal hyperalgesia and mechanical allodynia beginning on day 1 after cycloheximide injection. <b>B</b>, <b>D</b>) No differences in the nociceptive threshold were detected between cycloheximide and vehicle groups on the contralateral hind paw of these same rats over the entire experimental period. * <i>P</i><0.05, ** <i>P</i><0.01, as compared with baseline threshold of the same group. #<i>P</i><0.05, # # P<0.01, as compared with the cycloheximide group at the same time point. FWL: foot-withdrawal latency. White arrow: injection of CFA into an ankle; Black arrows: injection of saline (1% DMSO in saline) or cycloheximide into the hippocampus.