Figure 1.

GABA current rundown in oocytes expressing different GABA_AR subunit combinations. (A) Time course of GABA current rundown relative to α1β2γ2(●), α1β1(●), α1β2(●), α1β3(○) GABA_ARs. GABA currents are normalized to that elicited by the first GABA application (I_GABA: ●, 2720 ± 280 nA, n = 24; ●, 1264 ± 106 nA, n = 25; ●, 749±130 nA, n = 95; ○, 875 ± 139 nA, n = 30). (B) Representative evoked GABA currents at first, sixth GABA application of the rundown protocol and relative washout (black bars) (C) The bars represent mean ± SEM of GABA current rundown values in groups of oocytes expressing different GABA receptor subunit combinations as indicated. GABA current (%) has been calculated as the reduction in peak amplitude of the 6th GABA-evoked current as percent of the 1st current after the rundown protocol (six 10-s applications of 500 μM GABA at 40-s intervals). Statistical significance among the four groups was assessed with Kruskal-Wallis One Way Analysis of Variance on ranks with pairwise multiple comparison procedures (Dunn’s Method). * p < 0.05.