Figure 1. The effect of NPPB and FFA on GABA_CR currents.

A, Example experiments and mean data (2.5 mM Ca²⁺ n = 4, Ca²⁺-free n = 4) showing the effects of NPPB (50–100 µM) and FFA (100–200 µM) on the holding current in recordings from axon-severed BCTs, with subsequent addition of picrotoxin (PTX; 200 µM). NPPB/FFA(1) was measured 5–10 mins after drug application; NPPB/FFA(2) was measured 10–20 mins after application. B, Example GABA_CR responses evoked by local application of GABA (100 µM, 100 ms) and the charge of GABA-evoked responses against time for the recording in Ca²⁺-free conditions in A, with mean data (2.5 mM Ca²⁺ n = 2, Ca²⁺-free n = 4) showing the effect of NPPB and/or FFA on the charge of GABA-evoked responses. C, Example responses and mean data (n = 6) showing the effect of the GAT-1 inhibitor NO-711 (3 µM) on GABA-evoked responses (100 µM, 50–100 ms), and the associated increase in the tonic GABA_CR current. D, An example experiment in Ca²⁺-free extracellular solution and mean data (2.5 mM Ca²⁺ n = 3, Ca²⁺-free n = 4) showing the effect of NPPB (50 µM) and/or FFA (100–200 µM) on the holding current in recordings from the terminals of intact BCs, with subsequent addition of picrotoxin (200 µM). E, Mean data showing the effect of NPPB (50 µM) and/or FFA (100-200 µM) on the charge of GABA-evoked responses (2.5 mM Ca²⁺ n = 2, Ca²⁺-free n = 3) in recordings from the terminals of intact BCs. All experiments in this and subsequent figures were performed with CsCl-based intracellular solution at a holding potential of -60 mV in the presence of bicuculline (50 µM), unless stated otherwise. Example evoked currents show the average of 2–5 responses in each condition. Error bars represent SEM; * denotes P<0.05.