Regional changes in spinal cord glucose metabolism in a rat model of painful neuropathy

Spinal cord patterns of metabolic activity in a model of neuropathic pain were assessed in unanesthtized rats by the [ 14C]-2-deoxyglucose (2-DG) technique. Rats used in this procedure had demonstrable thermal hyperalgesia ipsilateral to sciatic nerve ligation and ipsilateral hind-paws that were lifted in a guarded position. The latter indicated possible spontaneous pain. Sciatic nerve ligation produced significant increases in glucose utilization in the dorsal and ventral horns of both sides, with greater activity present on the ipsilateral as compared to the contralateral side. Peak activity was in laminae V–VI, a region involved in nociceptive processing. Thus, a chronic increase in neuronal activity in these regions may reflect spontaneous neuropathic pain.