Motor-related frequency-selective synaptic responses of L5 Fezf2+CTB+ M1 IT-PNs. A, Representative EPSPs evoked by commissural stimulation at 10 and 25 Hz. B, Summary of the ratio of first and second EPSP amplitudes at 10 and 25 Hz stimulation. C, Response to current steps showing the membrane potential sag before (dark green and red) and after bath application of the Ih blocker ZD7288 (light green and red). D, Representative EPSP waveforms (top) before and after ZD7288 and changes in EPSP decay time constant, tau (bottom). ***p < 0.001 (paired t test).