Neuropathic pain model

Neuropathic pain was induced by segmental spinal nerve ligation (SNL). Animals were anesthetized with isoflurane. After the loss of righting reflex, the animal was fixed in the prone position. The SNL model was prepared as described previously ²⁷: a median skin incision with about 3-5 cm length in L4-S2 level of the mouse back was made, the muscles next to the vertebrae till the sixth lumbar protruding were separated, the L5/L6 joint protruding on the right side was exposed and excised, and L6 processus transversus was partially split so that the L4-L6 spinal nerves on the right side were exposed. L5 nerve was gently isolated and tightly ligated with 5-0 silk thread. The wound was closed with 4-0 silk thread suture and covered with iodine solution. After nerve ligation, animals with signs of paw clonus or autotomy were excluded from further experiments.