Behavioral manifestations of neuropathic pain after transplantation of bone marrow cells lacking CB2 receptors in irradiated CB2 +/+ mice
| Basal | Day 3 | Day 6 | Day 8 | Day 10 | Day 15 | |
|---|---|---|---|---|---|---|
| Contralateral side | ||||||
| PNL | ||||||
| Chimera-CB2 | 6.8 ± 0.52 | 5.7 ± 0.52 | 6.1 ± 0.58 | 5.3 ± 0.52* | 5.8 ± 0.8 | 5.1 ± 0.55* |
| CB2 −/− | 4.1 ± 0.2 | 4 ± 0.26 | 3.5 ± 0.26 | 3.2 ± 0.26* | 3.26 ± 0.26* | 3.3 ± 0.26* |
| CB2 +/+ | 4.7 ± 0.3 | 4.4 ± 0.32 | 4.1 ± 0.33 | 4.9 ± 0.3 | 5.2 ± 0.3 | 4.7 ± 0.3 |
| Chimera-WT | 5.6 ± 0.48 | 4.2 ± 0.48 | 5.2 ± 0.48 | 5.4 ± 0.48 | 5.4 ± 0.47 | 4.2 ± 0.48 |
| Sham | ||||||
| Chimera-CB2 | 6.2 ± 0.69 | 6.2 ± 0.69 | 6.9 ± 0.7 | 6.1 ± 0.36 | 7.2 ± 0.66 | 6.5 ± 0.46 |
| CB2 −/− | 4.2 ± 0.68 | 3.8 ± 0.8 | 4.4 ± 0.83 | 4.22 ± 0.44 | 4.45 ± 0.78 | 4.68 ± 0.54 |
| CB2 +/+ | 5.35 ± 0.76 | 4.2 ± 0.91 | 5.4 ± 0.92 | 4.3 ± 0.48 | 4.7 ± 0.88 | 4.5 ± 0.6 |
| Chimera-WT | 4.4 ± 0.62 | 4.2 ± 0.91 | 5.15 ± 0.75 | 5.4 ± 0.39 | 5.4 ± 0.72 | 5.1 ± 0.49 |
| Ipsilateral side | ||||||
| PNL | ||||||
| Chimera-CB2 | 6.5 ± 0.43 | 5.15 ± 0.42* | 5.6 ± 0.39* | 4.01 ± 0.28* | 4.1 ± 0.37* | 3.47 ± 0.29* |
| CB2 −/− | 3.74 ± 0.5 | 2.8 ± 0.4* | 2.03 ± 0.46* | 2.4 ± 0.321* | 2.54 ± 0.43* | 2.88 ± 0.34* |
| CB2 +/+ | 5 ± 0.45 | 2.58 ± 0.44* | 2.3 ± 0.42* | 2.84 ± 0.29* | 2.55 ± 0.38* | 2.59 ± 0.3* |
| Chimera-WT | 5.66 ± 0.5 | 3.23 ± 0.49* | 3.6 ± 0.46* | 3.6 ± 0.32* | 3.32 ± 0.43* | 2.6 ± 0.34* |
| Sham | ||||||
| Chimera-CB2 | 6.3 ± 0.53 | 5.6 ± 0.52 | 6 ± 0.34 | 6.1 ± 0.34 | 7.1 ± 0.47 | 6.2 ± 0.37 |
| CB2 −/− | 4.1 ± 0.63 | 3.8 ± 0.62 | 4.03 ± 0.59 | 4.44 ± 0.41 | 4.33 ± 0.54 | 4.5 ± 0.43 |
| CB2 +/+ | 4.8 ± 0.71 | 3.8 ± 0.69 | 4.02 ± 0.66 | 4.08 ± 0.46 | 4.51 ± 0.63 | 3.9 ± 0.48 |
| Chimera-WT | 4.6 ± 0.58 | 4.1 ± 0.56 | 5.5 ± 0.53 | 5.1 ± 0.38 | 5.4 ± 0.5 | 5.4 ± 0.39 |
Development of neuropathic pain in male CB2 +/+ (n = 10), CB2 −/− (n = 10), chimera-WT (n = 8), and chimera-CB2 (n = 12) mice. Thermal hyperalgesia after partial sciatic nerve ligation (PNL) was tested in the ipsilateral and contralateral paws on days 3, 6, 8, 10, and 15 after the surgery. Data were compared separately at the ipsilateral and contralateral side by ANOVA. CB2 −/− and chimera-CB2 mice developed allodynia on the contralateral side, but not CB2 +/+ or chimera-WT. The asterisks represent comparison between base values and the values measured at different time points.