Figure 4.

AMPAR-mediated currents are inwardly rectifying throughout development in a subset of 5-HT neurons. A: representative traces of evoked excitatory synaptic currents recorded from 5-HT neurons at holding potentials of −70 mV to +40 mV. B: average peak current-voltage curves with slight deviation from a linear relationship. C: rectification index of AMPAR currents, calculated as the ratio of peak amplitude at +40 mV divided by the peak amplitude at −70 mV for each cell. D: correlation between AMPAR EPSC τ decay and rectification index for each time point. P6, n = 14 cells (7 mice); P15, n = 8 cells (7 mice); P21–23, n = 11 cells (6 mice); P33–37, n = 10 cells (5 mice); P45–47, n = 10 cells (7 mice); P60–80, n = 12 cells (7 mice). Bar graphs represent means ± SE. *P < 0.05, one-way ANOVA followed by Tukey’s multiple comparison test.