Table 1. Behavioral testing.
| A. Paw-withdrawal test for mechanical allodynia | ||||||
| Days after SNI | Paw-withdrawal threshold (g) | Adjusted P-value | ||||
| Sham | SNI | SNI + siRNA IGF2 | 1 | 2 | 3 | |
| BL | 45.4±3.2 | 41.8±2.6 | 43.5±2.3 | 0.112 | 0.893 | 0.739 |
| D2 | 45.0±2.1 | 23.7±3.0 | 28.6±5.5 | <0.001 | 0.128 | <0.001 |
| D4 | 41.7±3.4 | 20.4±2.6 | 25.7±3.4 | <0.001 | 0.031 | <0.001 |
| D6 | 43.2±4.0 | 15.3±2.2 | 25.1±5.2 | <0.001 | 0.002 | <0.001 |
| D8 | 40.8±2.5 | 15.6±1.6 | 26.5±4.8 | <0.001 | <0.001 | <0.001 |
| D10 | 44.8±3.3 | 16.0±0.7 | 22.3±3.5 | <0.001 | 0.004 | <0.001 |
| B. Response duration following cold stimuli | ||||||
| Days after SNI | Painful behavior time (sec) | Adjusted P-value | ||||
| Sham | SNI | SNI + siRNA IGF2 | 1 | 2 | 3 | |
| BL | 0 | 1.2±0.6 | 1.3±0.9 | 0.018 | 1.000 | 0.006 |
| D2 | 1.0±0.8 | 6.7±0.9 | 3.4±0.6 | <0.001 | <0.001 | <0.001 |
| D4 | 1.4±0.8 | 15.0±2.0 | 8.9±3.5 | <0.001 | 0.001 | <0.01 |
| D6 | 2.0±0.7 | 13.6±1.2 | 9.2±1.1 | <0.001 | <0.001 | <0.001 |
| D8 | 1.2±0.7 | 14.5±1.3 | 11.1±1.6 | <0.001 | 0.001 | <0.001 |
| D10 | 1.2±0.6 | 17.5±1.5 | 14.3±0.7 | <0.001 | 0.004 | <0.001 |
SNI, spared nerve injury; siRNA, small-interfering RNA; IGF2, insulin-like growth factor-2; BL, baseline; D, day; Values are mean ± standard deviation; n = 6; adjusted P-value 1: sham group compared with SNI group; adjusted P-value 2: SNI + siRNA IGF2 group compared with SNI group; adjusted P-value 3: SNI + siRNA IGF2 group compared with sham group; The data presented above were examined by ANOVA followed by Bonferroni post hoc comparisons. P<0.05: statistically significant.