Fluoro-Gold tracing after chronic constriction injury of rat sciatic nerve

In the present study we have used Fluoro-Gold (FG) to retrogradely label primary sensory neurons in dorsal root ganglia (DRG) and motoneurons in ventral horn following chronic constriction injury of sciatic nerve (CCI). The neuropathic animals with fully developed tactile allodynia revealed a significant decrease of FG-labeled neurons in DRG L4-L5, three weeks after nerve-ligation. No such changes were detected in the DRG of sham-operated rats. The FG labeling in the motoneurons throughout L4-L6 spinal cord segments remained unchanged in both sham-operated and neuropathic groups. These data suggest that remodeling processes induced by CCI affect first of all the sensory pathways throughout the corresponding DRG.