Ih modulates firing properties in SGNs. (A) Representative traces (P1, apex) showing AP firing in WT SGNs in two different conditions. An initial spike was evoked from resting membrane potential (I = 0) by injecting depolarizing currents in 2-pA increments until threshold was reached (current-clamp protocol below). (B) Representative rebound spikes (P1, apex) were evoked after hyperpolarization of the membrane to potentials within the physiological range (at least −100 mV). Both initial spikes and rebound spikes were examined in the same cell. For each condition, representative recordings obtained in control (black traces) and in the presence of 100 µM ZD7288 (red traces) were superimposed for comparison. The insets show the same spike pairs on an expanded time scale. (C) Comparison of spike latency for initial spikes and rebound spikes (P1–3) before (black) and after 100 µM ZD7288 application (red). Error bars equal +1 SD. *, P < 0.05.
