AXONAL NEUROFILAMENTOUS ACCUMULATIONS - A COMPARISON BETWEEN HUMAN AND CANINE GIANT AXONAL NEUROPATHY AND 2,5-HD NEUROPATHY

The neuropathy produced by the hexacarbon 2,5-hexanedione (2,5-HD) res embles human and canine inherited giant axonal neuropathy (GAN) in the presence of giant axonal swellings that contain accumulations of neur ofilaments. The accumulations are both paranodal and internodal in GAN and 2,5-HD induced neuropathy. Detailed morphometry on the neurofilam ents reveals that the changes in human and canine GAN are closely simi lar and differ from those of 2,5-HD neuropathy, suggesting that the me chanisms underlying the formation of the axonal neurofilamentous accum ulations differ between the two conditions. In both human and canine G AN, the neurofilaments are more closely spaced and are of greater diam eter than in 2,5-HD neuropathy. The changes in the NF in GAN may be th e consequence of flattening of the side-arms of the neurofilaments aga inst the axis of the filaments