Figure 4

Effect of protein kinase C inhibitor bisindolylmaleimide I (BIM) on morphine modulation of [³H]GABA release. BIM is reported to reduce receptor desensitization and was used here to test whether morphine would elicit a bigger effect on [³H]GABA release in the presence of BIM. BIM is initially dissolved in DMSO whose effect on [³H]GABA release was also tested. BIM (1 μM) was present throughout the perfusion where indicated. Data represent averages ± SEM. Labels on the x-axis indicate concentration of morphine present during S2. The data show that morphine caused a reduction of [³H]GABA release as shown in Figure 2 but there was no statistical difference between experiments with or without BIM (One way ANOVA).