Spinal Nerve Ligation (Chung’s)

The International Association for the Study of Pain (IASP) defines neuropathic pain states as disorders that are characterized by lesions or dysfunction of the neural system that under normal condition transmit noxious information to the central nervous system. Neuropathic pain is produced by damage to, or pathological changes in the peripheral or central nervous systems. Neuropathic pain is a chronic pain. In contrast to nociceptive pain, it is described as "burning", "electric", "tingling", and "shooting" in nature. The hallmarks of neuropathic pain are chronic allodynia, hyperalgesia and paresthesia. Allodynia means that the pain comes on, or gets worse, with a touch or stimulus that will not normally cause pain.

Hyperalgesia means that patient gets severe pain from a stimulus or touch that will normally cause only slight discomfort. Paresthesia means that patient gets unpleasant or painful feelings even when there is nothing touching, or no stimulus. Neuropathic pain is less likely than nociceptive pain to be helped by traditional painkillers. However, antidepressant or anticonvulsant medications often work well to ease neuropathic pain.

Spinal nerve ligation (Kim and Chung, Pain (50) 1992: 355-363) model is a validated and widely used neuropathic model. We’ve successfully established and verified this model in our lab. The purpose of this experiment is preparing a rat neuropathic pain model of L5/L6 spinal nerve ligation, and using to study and screen drug candidates of antiallodynia for potential treatment of human neuropathy.