Figure 3. The time course of effects on percentage maximum possible effect in the tail flick test (left) and the colorectal distension test (right) during intrathecal infusion of morphine (Mor) at 0.3 [micro sign]g [middle dot] kg-1[middle dot] h-1(n = 6), lidocaine (Lid) at 200 [micro sign]g [middle dot] kg-1[middle dot] h-1(n = 6), or the combination of those (n = 6) for 6 days. Data are presented as the mean +/− SD. *Significantly different from 0.3 Mor. #Significantly different from 200 Lid.