Effects of gabapentin on thermal sensitivity following spinal nerve ligation or spinal cord compression

Neuropathic pain challenges healthcare professionals and researchers to develop new strategies of treatment and experimental models to better understand the pathophysiology of this condition. In the present study, the efficacy of gabapentin on thermal sensitivity following spinal nerve ligation and spinal cord compression was evaluated. The method of behavioral assessment was a well-validated cortically dependent operant escape task. Spinal nerve ligation produced peripheral neuropathic pain whereas spinal cord compression, achieved with an expanding polymer placed extradurally, produced a condition of central neuropathic pain. Changes in thermal sensitivity were also observed in animals undergoing nerve ligation surgery without nerve injury. Gabapentin (50 and 100 mg/kg) significantly reduced thermal sensitivity to 10 and 44.5 °C in surgically naive animals as well as those undergoing spinal nerve ligation and spinal cord compression. In conclusion, an operant method of behavioral assessment was used to show that spinal nerve ligation and spinal cord compression produced increases in sensitivity to noxious cold and heat stimuli. A decrease in thermal sensitivity was observed following administration of gabapentin. The results achieved with these methods are consistent with the clinical profile of gabapentin in treating conditions of neuropathic pain.