Activation of GABA_A receptors attenuated the peak current amplitude and enhanced the sustained current of ASIC1a.

<p>A, Example traces of a fast-inactivating transient current and a sustained current of ASIC1a activated by pH 3.5. GABA (100 μM) attenuated a fast-inactivating transient current and enhanced the sustained current of ASIC1a in HEK293 cells co-transfected with GABA_A receptor subunits (α₁ and β₂) and ASIC1a, which can totally abolished by co-application of picrotoxin (100 μM) with GABA. ASIC1a current traces were superimposed to the right (inset) (B). C, GABA had no effect on ASIC1a currents in HEK293 cells transfected with ASIC1a cDNA only. ASIC1a current traces were superimposed to the right (inset).