ABSTRACT
Axoplasmic transport has been shown to have at least three anterograde and two retrograde transport systems, however, only three major transport systems are fast anterograde transport, slow anterograde transport, and retrograde transport. Axonal transport is essential for the maintenance of neuronal integrity. The term neurotoxins include biological toxins, such as curari, diphtheria toxin, tetanous toxin, saxitoxin and a large number of new chemicals and drugs that are introduced every year. A number of chemically unrelated toxic compounds cause nerve fiber degeneration and inhibit fast and/or slow axonal transport. Spindle inhibitors such as colchicine and vinca alkaloids were probably the first neurotoxic compounds shown to disrupt axonal transport and cause axonal degeneration. n-Hexane and its metabolites, methyl n-butyl ketone, 2,5-hexanedione (HD), and its 3,4-dimethyl derivative, 3,4-Dimethyl-2,5-hexanedione, produce a common pattern of axonal degeneration in the central and peripheral nervous system, referred to as gamma-diketone neuropathy.
