FIGURE 4.

Scn10a^G1663S male mice show enhanced pain sensitivity to heat stimuli. (A) Male mutants show increased heat sensitivity in the Hargreaves test. Females n = 18–21/group; males n = 18–22/group. One-way ANOVA indicated a genotype difference in males and Sidak’s multiple-comparison test showed a significant difference in wt vs. homozygous males. The bar and p value represent the genotype effect in wt vs. homozygous males. (B) Mutant females had increased latency in the tail flick test. Females n = 19–20/group; males n = 16–20/group. The one-way ANOVA showed an overall genotype difference in females. The bar and p value represent the global genotype effect in females. No genotype effect could be seen in wt vs. heterozygous or wt vs. heterozygous females. (C-E) Hot plate test. The latency to the first hindpaw reaction is shown in left panels and the number of coping reactions in right panels. (C) Mutant mice showed no phenotype on the 47°C hot plate. n = 17–22/group; males n = 14–19/group. Kruskal–Wallis analysis on sex-separated or grouped animals showed no genotype difference for first hindpaw sign latency and a trend for coping reactions. The bar and p value represent the global genotype effect for coping reaction in sex-grouped animals. (D) Mutant males or females showed no genotype difference on the 50°C hot plate. Females n = 19–21/group; males n = 16–20/group. One-way ANOVA on sex-separated or grouped animals. (E) The male mutants were more sensitive than their wt counterparts on the 54°C hot plate. Females n = 17–22/group; males n = 16–20/group. Kruskal–Wallis analysis showed a global genotype effect in males. The bar and p value represent the global genotype effect in males. Data are expressed as means ± SEM in all panels. See Supplementary Table S7 for detailed statistical analysis.