Figure 7.
The persistent sodium current (INaP) increases during postnatal development in ChIs. A, Sample voltage clamp recording demonstrating INaP. Voltage clamp recordings were conducted in CdCl2 to eliminate calcium currents (Bennett et al., 2000). Treatment with ranolazine (1 μm) reveals the INaP current. B, Aggregate subtracted currents show a significant increase in INaP between P10 and P28 or adult (P120) ChIs. P10: n = 17 cells (3 mice), P28: n = 15(7), adult: n = 10(6). Data analyzed by two-way repeated measure ANOVA followed by Bonferroni post hoc test. Age × voltage: F(10,195) = 2.529, p = 0.0069. C–E, IV curves in ACSF or in the presence of ranolazine at (C) P10, (D) P28, or (E) adult (P120). Data analyzed by two-way repeated measure ANOVA followed by Bonferroni post hoc test. P10: age × voltage: F(5,135) = 0.3352, p = 0.8909; P28: age × voltage: F(5,160) = 4.998, p = 0.0003; adult: age × voltage: F(5,9) = 11.33, p < 0.0001. *p < 0.05, **p < 0.01, ***p < 0.001, ****p < 0.0001, ns is not significant, p > 0.05.