Abstract
Immunohistochemistry with antisera against tyrosine hydroxylase was performed on neurons with Alzheimer's neurofibrillary changes in the substantia nigra and locus ceruleus. These specimens were obtained from brains with Alzheimer's disease, Pick's disease, progressive supranuclear palsy, Alzheimer's type parkinsonism, parkinsonism-dementia complex on Guam, and normal aging. Under these neurologic conditions the affected cate-cholamine neurons with Alzheimer's neurofibrillary changes were stained positively with antisera against tyrosine hydroxylase. The results suggested that in these neurons, Alzheimer's neurofibrillary changes seemed to develop independently before the reduction of tyrosine hydroxylase protein synthesis.