Figure 2.

Cold allodynia and cold hyperalgesia in the Spared Nerve Injury and Spinal Nerve Ligation models of neuropathic pain. At 15°C both the SNI and SNL have significantly reduced latencies to withdrawal (A and B) compared to both naïve controls (n = 6). At 10°C the SNI model shows a significantly reduced latency (C), but the SNL model does not (D). The SNI shows cold allodynia (a significantly reduced response to a non-noxious temperature) at both 10°C and 15°C. The SNL model only displays this at 15°C. At -5°C, a temperature known to be painful in the naïve rat, the SNI model displays a further reduction in withdrawal latency (E); the SNL does not show any further reduction (F). Data are mean ± S.E.M.