Abnormal distribution of phosphorylated neurofilaments in neuronal degeneration induced by kainic acid.

An abnormal distribution of phosphorylated neurofilaments is present in some human neurodegenerative disorders including Parkinson's disease, Alzheimer's disease, and amyotrophic lateral sclerosis. This study reports the changes of phosphorylated neurofilaments observed in rat spinal cord after intrathecal injection of kainic acid. This receptor agonist of excitatory amino acid produces abnormal phosphorylation of neurofilaments in the cell body and proximal neurites of degenerating neurons. These immunocytochemical modifications observed 2 and 10 days after injections are predominantly located in ventral horn neurons. This study indicates that one of the neuronal responses to excitatory amino acid toxicity is the pathological distribution of phosphorylated neurofilaments in affected neurons. Pathological findings are comparable to those observed in neurodegenerative diseases such as amyotrophic lateral sclerosis.