Fig. 4.

Correlations between neuronal Ca²⁺ conductance (G_max) and action potential (AP) parameters. (A) Decreased G_max after injury correlated with prolonged AP duration (AP₅₀) in L5 dorsal root ganglia neurons of small cells (Pearson correlation r = −0.7, P = 0.0006), whereas G_max and AP duration among neurons from control rats were not related (r = 0.3, P = 0.232). (B) AP duration positively correlated with G_max in large cells from L4 and L5 dorsal root ganglia before injury (r = 0.78 ± 0.2, P = 0.0011), and this positive effect of increased G_max on AP duration was not affected by injury in neurons from L5 ganglia (r = 0.8 ± 0.2, P = 0.0055). (C) Decreased G_max after injury correlated to decreased afterhyperpolarization amplitude (AHP_ampl) in large neurons (r = −0.6, P = 0.0259), whereas changes in G_max did not predict changes in AHP_ampl in neurons from control rats (r = −0.09, P = 0.7249). SNL = spinal nerve ligation.