Human amyloid-beta1-42 has been suggested to be a pathogenetic factor in Alzheimer's disease. The precise mechanism by which this peptide causes the degeneration of neurons in the affected brain is not yet fully understood. By using immunohistochemistry we explored the inhibitory effects of human amyloid-beta1-42 applied in vivo on the fast axonal transport of acetylcholinesterase, the amyloid precursor protein, the vesicular acetylcholine transporter and synaptophysin in the sciatic nerve of rat. Our findings provide evidence for the in vivo neurotoxic effect of human amyloid-beta peptide.