RESUMEN
BACKGROUND: Many animal models can be used to study the underlying pathophysiological mechanisms of neuropathic pain. Most of these models rely on a partial denervation of the limb of the animal by ligating a selected nerve. In this study, we performed nerve lesions on three peripheral nerves supplying the plantar side of the rat hindpaw by differentially transecting the saphenous, the tibial, and the sural nerves alone or in paired combinations. METHODS: The development of neuropathic pain symptoms at three different anatomical areas (medial, central, and lateral) of the glabrous skin of the hindpaw was evaluated by sensory testing over a 12-wk period. Mechanical hyperalgesia (pinprick), cold allodynia (acetone), and abnormalities of hindpaw posture were continuously present in animals with tibial and tibial and saphenous nerve transection. RESULTS: Transection of the tibial and sural nerves induced cold allodynia and moderate mechanical hyperalgesia. Transection of the sural, the saphenous, or both nerves simultaneously induced no signs of specific neuropathic pain behavior and no abnormalities in posture of the affected hindpaw were noted after adequate stimulation. CONCLUSIONS: The overlapping innervation of nerve distribution can complicate the interpretation of nerve ligation studies of peripheral neuropathies.