Cell body remodeling during dying-back axonopathy: DRG changes during advanced disease.

Although the neuronal cell body functions critically in maintaining and repairing the axon, little attention has been focused on the soma during neurotoxin-induced dying-back of the axon. To help elucidate changes in the perikarya during axonal dying-back, this study employed the hexacarbon model of axonal neuropathy in a setting designed to maximize the chances of detecting structural alterations. A spectrum of cell body modifications occurred in the fifth lumbar dorsal root ganglia (DRG) of rats chronically exposed to 2,5-hexanedione. These included distinctive cytoplasmic remodeling, a perineuronal cell reaction, and evidence of neuronal death with neuronophagia. These findings suggest the importance of the cell body in the pathogenesis of neurotoxin-induced axonal degeneration and imply that complex soma-axon interactions may help determine the fate of intoxicated neurons.