Neuropathic pain after peripheral nerve injury in rats: a model using sciatic nerve clamping.

Various preclinical rodent models have been established and utilized to elucidate the mechanisms underlying neuropathic pain. However, the utility of existing major models faces challenges, such as reproducibility and surgical complexity. Here, we introduce a new rat model of neuropathic pain created by simply clamping the sciatic nerve for 10 min. First, we investigated pain-related behavior in 12 male Wistar rats after surgery to clamp the sciatic nerve that induced mechanical allodynia for 21 days and thermal hyperalgesia for 7 days (2-way ANOVA compared with sham-operated rats, p < 0.01). We observed only small interindividual differences in response to stimuli among the rats after sciatic nerve clamp surgery. The L5 dorsal root ganglion and spinal dorsal horn of the other 14 rats were subsequently sectioned and stained for Atf3 and Iba-1 immunoreactivity, respectively. Compared with sham surgery, nerve clamping induced peripheral and central sensitization (Mann-Whitney U test, p < 0.01). This new preclinical rat model of neuropathic pain offers procedural simplicity and high reproducibility.