A, cumulative plots indicating that the distribution of sIPSC amplitude was reversibly increased by 5-MT (20 μm). B, sIPSCs recorded under control conditions, during bath application of 5-MT and after washing off the agonist. C, Current clamp recording showing the changes of membrane potentials under control conditions, during bath application of KCl (15 mm) and after washing off KCl. KCl-induced depolarization triggered trains of action potentials in the recorded neuron. D, expanded view of AP spikes during KCl treatment. E, cumulative plots after KCl treatment indicating that the distribution of sIPSC amplitude was reversibly decreased by 5-MT (20 μm). F, sIPSCs recorded after KCl treatment under control conditions, during bath application of 5-MT and after washing off the agonist.