Figure 2.

Time course of mechanical, cold, and heat sensitivity following spared nerve injury. (a) Schematic representation of the spared nerve injury model showing ligation of the tibial and common peroneal nerves distal to the trifurcation. Spared nerve injury resulted in immediate mechanical (b) and cold (c) hypersensitivity. Latencies to heat stimulation at 50 and 55 °C decreased gradually and were significantly lower at 3 weeks after nerve injury than at (d and e) baseline. (f) Quantitative reverse transcription polymerase chain reaction analysis showed that trpv1 expression at 3 weeks after nerve injury was 179 ± 23% (P < 0.05) in the DRG and 147 ± 10% (P < 0.05) in the spinal cord relative to tissues from uninjured mice. Data are presented as means ± SEM (n = 6–18 mice per group; P < 0.05). trpv1, transient receptor potential vanilloid 1.