Superficial dorsal horn neuronal responses and the emergence of behavioural hyperalgesia in a rat model of cancer-induced bone pain

Animal models of cancer-induced bone pain have revealed a unique neurochemical reorganisation of segments of dorsal horn of the spinal cord receiving nociceptive input from the affected bone, and altered spinal neuronal response patterns. The aim of this investigation was determine correlations between the behavioural hyperalgesia and allodynia observed in these animals and the dorsal horn neuronal changes. The results show that in this rat model of cancer-induced bone pain, behavioural manifestations of pain emerge in parallel with the altered superficial dorsal horn neuronal response. Thus, in this model, the alterations in neuronal responses are a viable substrate for pharmacological studies on suprathreshold stimuli. In addition the clear temporal link between behavioural hyperalgesia and altered neuronal responses may provide an opportunity to investigate changes in dorsal horn gene expression in hyperalgesia. (C) 2004 Elsevier Ireland Ltd. All rights reserved.