Fig. 4

Inhibition of CaMKII-positive neurons in the ACC alleviates the CFA-induced decrease of the mechanical threshold. a Results of the eNpHR-CFA group. There was no effect of yellow light before CFA (off: 4.94 ± 0.22 g, on: 4.90 ± 0.36 g; n = 9). However, the mechanical threshold was increased when light was given after CFA injection (off: 3.05 ± 0.19 g, on: 4.16 ± 0.24 g; n = 9) [p = 0.011 in CFA and laser interaction, two-way repeated measures ANOVA]. b Result of eNpHR-Saline group. There was no light effect before (4.88 ± 0.21 g, on: 4.71 ± 0.24 g; n = 7) and after saline (off: 4.98 ± 0.23 g, on: 4.93 ± 0.27 g; n = 7). c Comparison of the post-test light ‘on’ period in all four groups. There was statistically significant difference between groups (p < 0.001, one-way ANOVA)