Modulatory Effects of Eschscholzia californica Alkaloids on Recombinant GABA_A Receptors

Figure 5

Effect of a benzodiazepine antagonist on the potentiation of α₅β₂γ₂ GABA_A receptors by (S)-reticuline. Application of 0.5 μM GABA was followed by application of 0.5 μM GABA/10 μM (S)-reticuline and subsequently by 0.5 μM GABA/10 μM (S)-reticuline/1 μM Ro15-1788. Providing (S)-reticuline would act at the benzodiazepine site elicited currents would be expected to go back to the size elicited by GABA alone. Instead, a potentiation was observed. Similar observations were made in two additional experiments.