A comparison the repetitive discharge characteristics of DRG cells produced by intracellular current injection. The discharge was evoked by injecting a series of depolarizing current pulses into DRG soma through the recording electrode. Differences in the discharges of the 3 categories of Aβ-fiber neuron are summarized. A. Colum bars showing the number of APs evoked by different magnitudes of intracellular depolarizing current injection. Left, 1 nA, 20 ms. Mid, 1.5 nA, 20 ms. Right, 2 nA, 20 ms. B. Representative examples of raw recordings to show the greater number of APs evoked by intracellular current injection in MS neurons. APs were evoked by current pulses of 2 nA, 20 ms. Left, control rat. Mid, neuropathic rat. Right, neuropathic rat. Details of the abbreviation are as indicated in Figures 2 and 4. Asterisks above the graph indicate a significant difference between control and neuropathic animals. *p < 0.05, **P < 0.01; ***p < 0.001.