HCN1 contributes to membrane properties in adult SGNs. (A) Mean resting potentials recorded from 14 adult SGNs of the indicated genotypes. Number of cells for each genotype is indicated below. *, P < 0.05. (B) Representative membrane responses to hyperpolarizing currents steps recorded from adult WT and Hcn1^−/− SGNs. The inset shows the rebound spike on an expanded time scale. (C) Sag potential was significantly (**, P < 0.01) diminished in adult Hcn1^−/− SGNs. (D) Mean rebound spike latency for adult Hcn1^−/− SGNs showed a significant delay relative to WT SGNs (*, P < 0.05). Error bars equal +1 SD.