DRG sensory neurons expressing Nav1.7‐I234T mutant channels display increased firing. (A–F) Heatmap of representative MEA recordings from DRG sensory neurons expressing Nav1.7‐I234T (A–C) or WT channels (D–F). The firing frequency of each active electrode is colour‐coded: white/red represents high firing frequency; blue/black represents low firing frequency. Each circle represents an active electrode within an 8 × 8 electrode array. (G) Mean firing frequency of neurons expressing Nav1.7‐WT channels and Nav1.7‐I234T mutant channels at 33, 37 and 40°C. *P <0.05, significantly different from WT; I234T, n = 4 experiments with eight rats; WT, n = 5 experiments with 10 rats. (H) Averaged number of active electrodes from neurons expressing Nav1.7‐WT or Nav1.7‐I234T channels at these three temperatures. *P <0.05, significantly different from WT.