Fig. 2.
Effects of the ventral tegmental area (VTA) miR-219-5p manipulation on affective aspects of nociception. (A) Rats receiving intraplantar injections of complete Freund’s adjuvant (CFA) spent less time in the pain-paired chamber (one-way ANOVA, F3, 16 = 7.29; post hoc test, **P < 0.01 vs. sham + vector group; n = 4 rats in sham + vector and sham + miR-219-5p-O/E groups and n = 6 rats in CFA + vector and CFA + miR-219-5p-O/E groups). MiR-219-5p-O/E treatment did not attenuate this negative affective state (P > 0.05 vs. CFA + vector group). (B–D) There were no differences among the groups in (B) the sucrose preference (SP) test (one-way ANOVA, F3, 20 = 0.31; n = 6 rats/group), (C) novelty suppressed feeding (NSF) test (one-way ANOVA, F3, 14 = 0.72; n = 4 rats in sham + vector and CFA + vector groups and n = 5 rats in sham + miR-219-5p-O/E and CFA + miR-219-5p-O/E groups), or (D) locomotion activity (LA) test (one-way ANOVA, F3, 15 = 0.65; n = 4 rats in sham + vector group and n = 5 rats in other groups). (E) Rats receiving intra-VTA injections of miR-219-5p-sponge spent less time in the pain-paired chamber (unpaired t test, t6 = 2.51, *P < 0.05 vs. vector group; n = 4 rats/group). (F–H) There were no differences among the groups in (F) the SP test (unpaired t test, t8 = 0.52; n = 5 rats/group), (G) NSF test (unpaired t test, t7 = 0.67; n = 4 rats in vector group and n = 5 rats in miR-219-5p-sponge group), or (H) LA test (unpaired t test, t7 = 0.59; n = 4 rats in vector group and n = 5 rats in miR-219-5p-sponge group). CPA = conditioned place aversion.