Effect of plantar local anesthetic injection on dorsal horn neuron activity and pain behaviors caused by incision.

Hypersensitivity after tissue injury is an expression of neuronal plasticity in the central nervous system. This has been explored most extensively using in vitro preparations and animal models of inflammatory pain and chemical irritation. For pain after surgery, a similar process has been proposed.

Characterization of a rat model of incisional pain.

In this study, we developed a rat model of incisional pain. A 1-cm longitudinal incision was made through skin, fascia and muscle of the plantar aspect of the hindpaw in halothane-anesthetized rats. Withdrawal responses were measured using von Frey filaments at different areas around the wound before surgery and for the next 6 days.