Contribution of spinal glia activation to mechanical hyperalgesia induced by spared nerve injury in rats

Objective: To investigate the role of spinal glial cells activation in neuropathic pain in a recently developed spared nerve injury (SNI) animal model by Decosterd and Woolf. Methods: A lesion was made to two of the three terminal branches of the sciatic nerve of rats (tibial and common peroneal nerves) leaving the sural nerve intact. Continuous intrathecal administration of propentofylline, a glial modulating agent, 1d before and 5 d after operation, was performed to disrupt spinal cord glia function. The vehicle was intrathecally administrated as control. The paw withdrawal threshold to mechanical stimulation (paw withdrawal mechaical threshold PWMT), body mass and motor function were determined pre- and post-surgery. Results: It produced a prolonged mechanical allodynia in the medial and lateral part of the ipsilateral hind paw in SNL models. The treatment with propentofylline significantly prevented the development of mechanical allodynia located in either medial or lateral plantar surface. Rats in two groups showed normal motor function and body weight increase. Conclusion: SNI model can be applied as a useful method with little variance in searching the mechanism of neuropathic pain. These study suggest that spinal gha activation may contribute to mechanical allodynia induced by SNI.

Contribution of spinal glia activation to mechanical hyperalgesia induced by spared nerve injury in rats

Objective: To investigate the role of spinal glial cells activation in neuropathic pain in a recently developed spared nerve injury (SNI) animal model by Decosterd and Woolf. Methods: A lesion was made to two of the three terminal branches of the sciatic nerve of rats (tibial and common peroneal nerves) leaving the sural nerve intact. Continuous intrathe-cal administration of propentofylline, a glial modulating agent, 1 d before and 5 d after operation, was performed to disrupt spinal cord glia function. The vehicle was intrathecally administrated as control. The paw withdrawal threshold to mechanical stimulation (paw withdrawal mechaical threshold PWMT), body mass and motor function were determined pre- and post-surgery. Results: It produced a prolonged mechanical allodynia in the medial and lateral part of the ipsilateral hind paw in SNL models. The treatment with propentofylline significantly prevented the development of mechanical allodynia located in either medial or lateral plantar surface. Rats in two groups showed normal motor function and body weight increase. Conclusion: SNI model can be applied as a useful method with little variance in searching the mechanism of neuropathic pain. These study suggest that spinal glia activation may contribute to mechanical allodynia induced by SNI.