Fig. 1

Analgesia of established MIA-OA pain by DRG-AAV6-3.2iPA2 in male rats. Animal protocol is schematically outlined (A). The time courses for the group averages of sensitivity to vF, Pin, Heat, Cold, and weight bearing (Wb) before and after DRG injection of either AAV6-3.2iPA2 or AAV6-3.2NP (B–F); *p < 0.05, **p < 0.01, and ***p < 0.001 for comparisons to tBL within the group and ^#p < 0.05, ^##p < 0.01, and ^###p < 0.001 for comparisons between the groups post-AAV injection. Repeated measures parametric two-way ANOVA for vF, Heat, and Wb followed by Tukey post hoc, and non-parametric Friedman ANOVA for pin and cold tests and Dunn’s post hoc. Right panels of B–F show tAUCs calculated using the measures 14-day post-MIA and immediate before vector injection as tBL; **p < 0.01 and ***p < 0.001, comparisons of tAUCs between the groups (unpaired, two-tailed Student’s t tests for vF, Heat, and Wb and Mann–Whitney U tests for pin and cold). G The time courses (3 h) of sensitivity to vF and Pin after GBP (100 mg/kg, i.p.) in MIA+AAV-3.2PN rats, performed at the time point as indicated in A–C; **p < 0.01 and ***p < 0.001 vs. before GBP, repeated measures one-way ANOVA for vF with Tukey post hoc, and ^###p < 0.001 for pin Friedman and Dunn’s post hoc. H Comparison of the efficacy between AAV-3.2iPA2 analgesia in MIA and GBP (i.p.) in 3.2NP rats by vF and pin tests, ***p < 0.001, and unpaired two-tailed Student’s t test for vF and Mann–Whitney U test for Pin. I Results of the CPP difference scores (seconds) of saline-paired chamber and the GBP-paired chamber between AAV-3.2iPA2 and AAV-3.2NP, ***p < 0.001 (unpaired, two-tailed Student’s t test)