We examined GABA-activated single-channel currents in cell-attached patches on dentate gyrus granule neurons in rat hippocampal slices. We found that GABA activated three different types of extrasynaptic GABAA receptors (GABARex I, II and III). These receptors were activated with a delay, varied in their affinity for GABA and maximal conductance and were differentially modulated by drugs. The channel conductance of GABARex I was enhanced by 1 μM diazepam or 200 nM zolpidem. GABARex II was modulated by 1 μM flumazenil and the channel conductance of GABARex III increased in 50 nM THDOC. The receptors’ apparent affinity for GABA (EC50) were in the nanomolar range. It was 27 nM, 4 nM and 43 nM for GABARex I, II and III, respectively. In 1 μM diazepam, the GABA EC50 of GABARex I was shifted to 2 nM. The maximal conductance obtained in 1 μM or higher GABA concentration was receptor-type specific. It was 61±3 pS, 85±8 pS and 43±3 pS for GABARex I, II and III, respectively. Diazepam did not increase the maximal conductance of GABARex I. The results show how the tonic inhibition can be graded and precisely set by the different types of receptors, the GABA concentration and other drugs that may be present.