Inducing Orofacial Neuropathic Pain in a Rat Model via Infraorbital Nerve Ligations

Begin with an anesthetized rat restrained on a surgical bench.

Apply an ointment to the eyes to prevent dryness.

Use retractors to open the mouth and retract the lip.

Next, make an incision between the dorsal gum and lip, and remove the soft tissue to expose a branch of the infraorbital nerve.

This nerve transmits the orofacial signals from the face and mouth to the brain.

Place two ligatures around the infraorbital nerve to constrict it, which results in nerve injury and axonal damage.

The injured nerve triggers the release of pro-inflammatory molecules by the immune cells. These molecules attract more immune cells and lead to an exaggerated immune response.

This increases the excitability of the damaged nerve and generates intense signals that travel to the brain. These intense signals are interpreted as neuropathic pain.

Apply an adhesive to close the wound. The rat is now ready for the orofacial pain assay.