Figure 2.
Effect of Ih on single sEPSP waveforms. A, Somatic sEPSP traces from a simultaneous dendritic and somatic current-clamp recording (see inset). sEPSPs were evoked by injection of an EPSC-like double-exponential waveform (τrise = 0.3 ms; τdecay = 3 ms; 500 pA). Control and ZD 7288 traces from the same experiment are overlaid to allow for a direct comparison of the shape of the sEPSPs with and without Ih. The thin and thick lines represent responses to somatic and dendritic current injections, respectively. B, The propagated sEPSP from injection at the dendritic location (134 μm) was superimposed and scaled to the peak of the sEPSP from injection at the soma to show the effect of distance on the PSPs. Waveforms in both the control situation (open) and after application of ZD 7288 (red) are presented. The rise time (C) and integral (D) of somatic sEPSPs are plotted as a function of distance from the injection site. The data points at the soma are the mean ± SEM of 7–20 recordings including 3–5 double somatic recordings.