Can be used to induce pain to test analgesics.

The sciatic nerve is exposed by blunt dissection and injured with four loose chromic gut ligatures.  In control animals the sciatic nerve is exposed without manipulations (sham procedure). Rodents with chronic constriction injury show changes in the posture of the ipsilateral hind paw and sensitivity to cold and mechanical (Von Frey) allodynia and thermal hyperalgesia. These signs of neuropathic pain remain up to several months.