SHORT-TERM AXOTOMY-INDUCED CHANGES IN THE RAT LUMBAR DORSAL-ROOT GANGLIA - AN IMMUNOHISTOCHEMICAL STUDY

The short-term axotomy induced changes in both neurofilament triplet protein (NFP) and neuron-specific enolase (NSE) immunoreactivites (IR) were studied in the rat lumber (L4-L6) dorsal root ganglia (DRG) 1, 3, 7 and 14 days after sciatic nerve transection. Control DRG showed NFP IR only in the axons whereas perikarya were unlabeled. The axotomy causes the presence of NFP IR in a subpopulation (mainly large and intermediate) of primary sensory neurons and increase in a time-dependent manner in both the number (1.3% at 3 days to 11.8% at 14 days) and the intensity of IR (188.8+/-26.4 at 3 days to 153.9+/-33.8 at 14 days) for NFP IR. However, no morphological evidence of chromatolysis was observed in NFP IR perikarya. On the other hand, all the primary sensory neurons from control DRG were NSE IR with a variable intensity of staining which was not related to the neuron size. No significant changes were observed in NSE IR of the large and intermediate sized neurons, and a non significant decrease in IR intensity of the small sized ones was noticeable for all the axotomized DRG. These results suggest that short-term axotomy induces perikaryal accumulation of NFP in a subpopulation of primary sensory neurons (mainly large and intermediate in size while it did not modify a apparently the NSE-IR.