Neurofibrillary axonal pathology in aluminum intoxication

Aluminum chloride injected into the cisterna magna of 3‐to 4‐week‐old rabbits is known to produce neurofibrillary changes in the perikarya and dendrites of neurons of the spinal cord and brainstem. This report calls attention to the early appearance and prominence of neurofibrillary swellings in proximal axons of affected neurons. One and 2 days after intoxication, large axonal swellings containing maloriented neurofilaments were present in the ventral horns. Over the next days and weeks, neurofilaments accumulated in the neuronal perikarya and dendrites. Two months after injection, abnormalities in the cell bodies were less apparent but occasional giant axonal swellings persisted in the ventral horn. This sequence of pathological changes, reflecting disorganization of the neuronal cytoskeleton, may result from an increase in synthesis of neurofilament polypeptides, and impairment in integration of these constituents into the neuronal cytoskeleton, or a defect in the intracellular transport of neurofilaments.