Immunohistochemical analysis of spinal cord lesions in amyotrophic lateral sclerosis using microtubule-associated protein 2 (MAP2) antibodies

We have studied microtubule-associated protein 2 (MAP2) expression in anterior horn neurons in the cervical and lumbar spinal cords of 19 cases of adult-onset sporadic amyotrophic lateral scerlosis (ALS) using immunohistochemistry. Specimens from 7 patients without neurological disease served as controls. MAP expression decreased in the anterior gray horn of all ALS cases and in the intermediate gray of several ALS cases. Such reduction correlated with the degree of degeneration or neuronal loss in anterior horn cells and with the clinical symptoms of limb weakness. Cytopathologically, the MAP2 immunoreactivity decreased corresponding to the occurrence of individual signs of neuronal degeneration, such as chromatolytic neurons, shrunken neurons and pigmented neurons. MAP2 expression was relatively well preserved in the specimens in which spheroids are conspicuous. The findings of this study demonstrate MAP2 to be an excellent market for the detection and quantification of anterior horn degeneration in ALS.