Figure 7.

MCC Cg1^Glu play a facilitating role in pain modulation and neuropathic pain. A, Schematic drawing of the sites for virus injection and optical stimulation (left) and the expression of ChR2-eYFP in MCC Cg1 (right). Scale bar, 500 μm. B, Optical activation of unilateral MCC Cg1^Glu reduced PWT in intact mice and deteriorated allodynia contralaterally in neuropathic mice. Before PSL, n = 10/group, two-tailed unpaired t test, laser on once versus laser off, p < 0.001, t = 7.574, df = 18. After PSL, laser off n = 10, laser on once and laser on daily n = 9/group, one-way ANOVA with Tukey's post hoc; D7: F_(2,25) = 4.478, p = 0.0218, laser on daily versus laser off, p = 0.0235; D14: F_(2,25) = 9.294, p = 0.001, laser on daily versus laser off, p < 0.001. C, Optical activation of unilateral MCC Cg1^Glu induced place aversiveness in neuropathic mice. Sham n = 7, PSL n = 6, two-way ANOVA with repeated measures and Bonferroni's post-test (F_(2,46) = 3.352, p = 0.0438). PSL group, test versus preconditioning, p = 0.0407. D, Optical inhibition of unilateral MCC Cg1^Glu elevated PWT in intact mice and alleviated allodynia contralaterally in neuropathic mice. Before PSL, n = 10/group, two-tailed unpaired t test, laser on versus laser off, p = 0.0277, t = 2.395, df = 18. After PSL, laser off n = 10, laser on once n = 9, laser on daily n = 8, one-way ANOVA with Tukey's post hoc. D7: F_(2,24) = 4.759, p = 0.0182, laser on daily versus laser off, p = 0.0241; D14: F_(2,24) = 13.08, p < 0.001, laser on daily versus laser off, p < 0.001. E, Optical inhibition of unilateral MCC Cg1^Glu did not induce place preference in neuropathic mice. Sham n = 6, PSL n = 10, two-way ANOVA with repeated measures and Bonferroni's post-test (F_(2,58) = 0.2498, p = 0.7798). *p < 0.05, ***p < 0.001.