Reductions in baseline D2/D3R BPND in the CNBP sample | Right ventral striatum, (4,16, 0), Z = 3.7, 400 mm3, 21% | Positive affect at baseline (PANAS) | r = −0.59; p = 0.02* | r = −0.17; p = 0.54 | r = −0.25; p = 0.16 |
Total volume of hypertonic saline infused (mL) | r = −0.66; p = 0.007** | r = −0.10; p = 0.71 | r = −0.20; p = 0.28 |
Pain sensitivity (VAS/total volume) | r = 0.54; p = 0.048* | r = 0.32; p = 0.25 | r = 0.39; p = 0.04* |
| | Baseline MOR BPND in the right amygdala, (24, −2, −24), Z = 2.6, 1472 mm3 | r = 0.65; p = 0.009** | | |
| | Baseline MOR BPND in the left amygdala, (−22, −6, −24), Z = 2.6, 592 mm3 | r = 0.55; p = 0.03* | | |
| | Pain-induced MOR activation in the left amygdala, (−20, −6, −20), Z = 3.4, 912 mm3 | r = −0.57; p = 0.03* | | |
Pain-induced D2/D3R activation across all subjects (HC, CNBP) | Left caudate nucleus, (−18, 20, 2), Z = 4.8, 1600 mm3, 6% | Pain unpleasantness (VAS) | r = −0.35; p = 0.25 | r = 0.65; p = 0.02* | r = −0.04; p = 0.87 |
| Left putamen, (−30, 4, 4), Z = 4.7, 648 mm3, 6% | | | | |
| Right nucleus accumbens, (16, 12, −4), Z = 4.1, 2072 mm3, 5% | | | | |
Reductions in pain-induced D2/D3R activation in the CNBP sample | Right ventral striatum, (6, 14, 2), Z = 3.4, 328 mm3, 130% | | | | |