Baseline nociceptive sensitivity and inflammatory and neuropathic hyperalgesia in wild-type and sns-α2−/− mice
| Acute nociception | Inflammatory hyperalgesia/paw swelling | Neuropathic hyperalgesia | Capsaicin-induced sensitization Mechanical (AUC, g×h) | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Thermal (PWL, s) | Mechanical (PWT, g) | Chemical (flinches/5 min) | Thermal (AUC, s×d) | Mechanical (AUC, g×d) | Paw swelling (AUC, ml×h) | Thermal (AUC, s×d) | Mechanical (AUC, g×d) | ||
| α2fl/fl | 15.0 ± 0.6 | 3.0 ± 0.1 | 49.5 ± 6.6 | 33.3 ± 4.6 | 9.1 ± 0.3 | 3.62 ± 0.42 | 224 ± 9 | 47.3 ± 1.5 | 4.6 ± 0.24 |
| (n = 6) | (n = 6) | (n = 6) | (n = 6) | (n = 6) | (n = 6) | (n = 6) | (n = 6) | (n = 5) | |
| sns-α2−/− | 14.5 ± 0.8 | 3.1 ± 0.1 | 49.0 ± 7.1 | 33.0 ± 4.6 | 10.6 ± 0.7 | 3.25 ± 0.31 | 230 ± 8 | 44.8 ± 1.4 | 4.5 ± 0.22 |
| (n = 10) | (n = 10) | (n = 6) | (n = 10) | (n = 10) | (n = 10) | (n = 6) | (n = 6) | (n = 6) | |
Paw withdrawal latencies (PWL; s) in response to stimulation with defined radiant heat, mechanical thresholds (PWT; g) in response to stimulation with electronic von Frey filaments, and numbers of flinches within 5 min after subcutaneous injection of capsaicin (1.6 μg in 10 μl) in sns-α2−/− mice and in wild-type (α2fl/fl) littermates. Hyperalgesia was quantified as the area under the curve (AUC) of the change from baseline sensitivity plotted versus time. p > 0.1 (unpaired t test) for all comparisons between genotypes. All values mean ± SEM.