Immunohistochemical studies with antibodies to neurofilament proteins on axonal damage in experimental focal lesions in rat.

Immunohistochemistry with monoclonal antibodies against neurofilament (NF) proteins of middle and high molecular weight class, NF-M and NF-H, was used to study axonal injury in the borderzone of focal lesions in rats. Focal injury in the cortex was produced by infusion of lactate at acid pH or by stab caused by needle insertion. Infarcts in substantia nigra pars reticulata were evoked by prolonged pilocarpine-induced status epilepticus. Immunohistochemical staining for NFs showed characteristic terminal clubs of axons in the borderzone of lesions. Differences in the labelling pattern occurred with different antibodies which apparently depended on molecular weight class of NFs and phosphorylation state. These immunohistochemical changes of NFs can serve as a marker for axonal damage in various experimental traumatic or ischemic lesions.