Figure 1. The time course of changes of the mean tail withdrawal latency (+/- SEM) and median motor score after epidural and intrathecal administration of various doses of n-butyl-p-aminobenzoate (upper, closed symbols) and bupivacaine (lower, open symbols). All groups contained five rats. Significant difference of the mean tail withdrawal latency and median motor score determined in an active treatment group versus the control group are indicated by *P < 0.05 and **P < 0.01.