The pentameric a type γ-aminobutyric acid receptors (GABAARs) are the major inhibitory neurotransmitter receptors in the nervous system and have long been considered as important pharmaceutical targets for the treatment of multiple neurological or psychological disorders.Here, we show that 2-guanidine-4-methylquinazoline (GMQ), a recently identified acid-sensing ion channel (ASIC) modulator, strongly and preferentially inhibits GABAAR.