Figure 4.

Excitability changes of DRG neurons by dorsal root stimulation. (a-b) Dorsal root current threshold was defined by the chronaxie curve (threshold-duration), which was determined as the minimum stimulus current to the dorsal root sufficient to evoke a soma AP with pulses of 0.2, 1, 2, 4 and 6 ms duration. A reduction in the rheobase in DRG neurons is shown in the NEP and CIP models. MS (B) neurons showed significant reduction with a 0.2 ms pulse. (c–e). Representative examples of MS neurons raw recordings to demonstrate the greater number of APs evoked by dorsal root stimulation in control (c) versus NEP model (d) and CIP model rats (e). *P < 0.05, **P < 0.01; Kruskal–Wallis tests with post hoc Dunn’s multiple comparison tests were used to compare SD rat groups. Other abbreviations are as indicated in Figure 1.