PHE induces an inward current and a long-lasting depression of AMPAR-EPSCs in DRn 5-HT neurons. A, Illustration of a typical inward current induced by bath application of PHE (100 μm) in putative DRn 5-HT neurons. B, Depiction of the effect of bath application of PHE (100 μm) on the amplitude of AMPAR-EPSCs. C, Left, Summary graph of the effect of PHE (100 μm) on the amplitude of AMPAR-EPSCs (n = 15). Right, Superimposed EPSC traces taken at time points indicated by numbers in C. D, Illustration of the average amplitude of EPSCs measured during bath application of PHE (PHE acute) and after washout of PHE (PHE-LTD). PHE induces an LTD of AMPAR-EPSCs. Calibration: 50 pA, 10 ms.