A. Effect of lidocaine or aCSF microinjected into the lateral PB on latency to heat-evoked withdrawal. Latency was significantly increased during lidocaine block of PB (t25 = 2.17, p = 0.040, n = 26), but unaffected by injection of aCSF (t14 = 0.43, p = 0.68, n = 15). B. Effect of lidocaine microinjected into the lateral PB on withdrawal evoked by VF probes (26, 60 and 100 g, n = 22, number of animals not responding within 8 s cut-off time shown within each bar). Latency was increased for stimuli in the noxious range (60 g: W = 243, p < 0.0001, n = 22; 100 g: W = 203, p = 0.0004, n = 22) but not for the 26 g stimulus (W = 31, p = 0.13, n = 22). PB injections were contralateral to the peripheral stimulus. (Data shown as mean + SEM, *p < 0.05, **p < 0.01 compared to baseline using t-test for correlated means or Wilcoxon’s signed ranks test.)