FIGURE 6.

The elevation of mechanical pain thresholds in Slack^–/– mice after the compensatory expression of the Slack channel in spinal SOM⁺ neurons. (A) Experimental timeline design for adult behavior test (upper). The GFP expression in the SOM⁺ neurons in the spinal cord dorsal horn after ITH (left), no GFP signal in the DRG after ITH (right). (B) Mechanical pain thresholds estimated by von Frey tests in different mice groups: SOM⁺-tomato⁺-WT mice (n = 9), SOM⁺-tomato⁺-Slack^–/– mice (n = 18), SOM⁺-tomato⁺-WT + GFP mice (n = 9), and SOM⁺-tomato⁺-Slack^–/– + KCNT1 mice (n = 9). The significant difference of mechanical pain threshold was shown between SOM⁺-tomato⁺-WT and SOM⁺-tomato⁺-Slack^–/– mice (One-way ANOVA, Q-value = 3.296, P = 0.01). The significant difference of mechanical pain thresholds between SOM⁺-tomato⁺-Slack^–/– + KCNT1 mice and SOM⁺- tomato⁺- Slack^–/– + GFP mice (One-way ANOVA, Q = 2.157, P = 0.008) or SOM⁺-tomato⁺-WT mice (Q = 1.506, P = 0.023) were also shown. *P < 0.05, ^**P < 0.01, ^***P < 0.001. (C) Mechanical pain thresholds were assessed by the Randall-Sellito test in different groups of mice as indicated. Significant difference of mechanical pain threshold was shown between SOM⁺-tomato⁺-WT (n = 9) and SOM⁺-tomato⁺-Slack^–/– mice (n = 18, One-way ANOVA, P = 0.014); The significant difference of mechanical pain thresholds between SOM⁺-tomato⁺-WT + GFP mice (n = 9) and SOM⁺- tomato⁺- Slack^–/– + GFP mice (n = 9, P = 0.01); between SOM⁺-tomato⁺-Slack^–/– + GFP mice (n = 9) and SOM⁺- tomato⁺- Slack^–/– + KCNT1 mice (n = 9, P = 0.04) were also shown. (D,E) No significant difference of thermal pain (D) and cold pain (E) sensitivity between SOM⁺-tomato⁺-WT mice and SOM⁺-tomato⁺-Slack^–/– mice before and after ITH (unpaired itT-test, P = 0.58 and P = 0.4, respectively).