Effects of 5-HT on mIPSCs. (A) Effect of 5-HT (50 μM) on mIPSCs in the presence of TTX (0.5 μM). Frequency, but not amplitude of mIPSCs increased following 5-HT application. Lower typical traces of mIPSCs were taken before (control) and after the onset of 5-HT application in the presence of TTX. (B, C) Cumulative probability of the inter-event interval and amplitude of mIPSCs were obtained from the neuron (A). (D) The change in frequency during 5-HT was significantly different from control (**P < 0.01, K-S test), the amplitude during 5-HT was not different from the control (K-S test, P > 0.05, n = 5).