Neurotoxic action of 2,5-hexanedione on the autonomic nervous system: ultrastructural and functional alterations in the rat sympathetic superior cervical ganglion.

In rats treated for 14 days with 2,5-hexanedione, the efficiency of ganglionic transmission was markedly reduced whereas only faint ultrastructural changes occurred in a few preganglionic fibers; evident signs of axonal pathology were observed on the 30th day of treatment. Choline acetyltransferase activity and acetylcholine formation showed no alteration at any time. The autonomic system is affected early during 2,5-hexanedione neuropathy, functional changes being more marked than morphological lesions.