Figure 4

CFA injection increases the number of action potentials evoked by ramp current stimulation. (A) Examples of APs evoked by 300 pA (left) and 500 pA (right) ramp current stimulation from NS (top) and CFA-injected (bottom) rats. (B) Bar graph showed a significant increase in numbers of APs evoked by 300 pA (left) and 500 pA (right) ramp current stimulation in NS- or CFA-injected rats (**p < 0.01, compared with NS, Mann-Whitney test). (C) Bar graph representing the mean time to first spike (TTFS) in response to a 300 pA (left) or 500 pA (right) ramp current injection from NS or CFA-injected rats (*p < 0.05, compared with NS, Mann-Whitney test). (D) Mean interspike interval (ISI) in a spike train of TMJ neurons responding to a 300 pA ramp current stimulation from NS- or CFA-injected rats (*p < 0.05 compared with NS, Mann-Whitney test). (E) Mean ISI in a spike train of TMJ neurons responding to a 500 pA ramp current stimulation from NS- or CFA-injected rats (*p < 0.05 compared with NS, Mann-Whitney test).