Figure 2

Normal pain behaviors and locomotor activity in P311^-/- mice. A. Acute pain measured by mechanical threshold was comparable between wild-type (n = 8; white bars) and P311^-/- mice (n = 9; black bars). B-D. Responses to noxious thermal stimuli were measured by the paw withdrawal latency to Hargreaves test (B), hotplate (C) and the water immersion tail-flick latency (D). Thermal pain in all tests did not differ between wild-type (n = 8; white bars) and P311^-/- mice (n = 9; black bars). Student's t-test, P > 0.05. E. Motor function assessed by the rotarod test was not affected in P311^-/- mice (n = 9; filled circles) compared with wild-type mice (n = 8; open circles). Repeated measures analysis of variance; P > 0.05. F. Spontaneous pain responses induced by formalin were comparable between wild-type (n = 9; open circles) and P311^-/- mice (n = 10; filled circles). Repeated measures analysis of variance; P > 0.05, Phase I (0–10 min); P > 0.05, Phase II (10–60 min). G. Travel distance was monitored during the pre-test (day 1) and post-test day (day 5) of experiment by the ANYMAZE software. There was no significant difference between wild-type and P311^-/- mice on both the pre-test and post-test day. And the travel distance was not affected by formalin injection in either wild-type or P311^-/- mice. n = 16 for each group. Student's t-test, P > 0.05.