The D1DR/D2DR antagonists-induced antinociception in TCI rats was mediated by NMDAR. (a, b) The mechanical thresholds of TCI rats after coadministration of SCH 23390/L-741,626 with NMDA (0.05 μg/20 μL, i.t.) (NMDA was administered 30 min before SCH 23390/L-741,626 treatment). (c, d) The mechanical thresholds of TCI rats after coadministration of SCH 23390/L-741,626 SCH 23,390 with LY359549 (n = 6, # P < 0.05, ## P < 0.01, compared with TCI + SCH 23390/L-741,626 group, * P < 0.05, ** P < 0.01, compared with 0 h, &P < 0.05, &&P < 0.01, compared with Sham + Vehicle group, D1DR antagonist SCH 23390, D2DR antagonist L-741,626, NMDAR antagonist LY 359549, and NMDAR agonist NMDA, Vehicle: 25% DMSO).