Figure 1.

Age dependence of firing properties of IB4+ and IB4− dorsal root ganglia (DRG) neurons. (a) Average number of action potentials (APs) fired in response to incremental 500 ms current steps. Left panel: Data for IB4+ neurons. The effect of age is statistically significant (F = 12, p < 0.001, one‐way repeated‐measures ANOVA; n: 1 m = 11, 3 m = 13, 5 m = 11, 8 m = 22, 12 m = 6, 18 m = 13) with neurons from 8‐month‐old mice firing more APs than neurons from the youngest (p = 0.0001) and oldest (p = 0.02) mice (Bonferroni post hoc test). Right panel: Data for IB4− neurons. The effect of age is not statistically significant (F = 0.9, p = 0.5, one‐way repeated‐measures ANOVA; n: 1 m = 10, 3 m = 10, 5 m = 11, 8 m = 24, 12 m = 6, 18 m = 20). (b) Example traces show voltage responses to 500 ms 300 pA current injections for IB4+ and IB4− DRG neurons from mice of different ages