Responses of spinal dorsal horn neurons to foot movements in rats with a sprained ankle

摘要: Acute ankle injuries are common problems and often lead to persistent pain. To investigate the underlying mechanism of sprain pain, response properties spinal dorsal horn neurons were examined after sprain. was induced manually by overextending a rat hindlimb in direction plantarflexion inversion. The weight-bearing ratio (WBR) affected foot used as an indicator Single unit activities inversion or compression recorded from medial part deep horn, laminae IV-VI, normal ankle-sprained rats. One day sprain, rats showed significantly reduced WBRs on foot, this reduction partially restored systemic morphine. majority responded single stimulus modality. After mean evoked rates increased, afterdischarges developed neurons. sprain-induced enhanced responses morphine, which reversed naltrexone. data indicate that movement-specific neuron morphine-dependent manner, thus suggesting hyperactivity is pain