Cytoskeletal immunohistochemistry of Alzheimer's disease

The first half of this paper is devoted to a review on the cytoskeletal immunocytochemistry of the various morphological changes in Alzheimer's disease (AD), i.e. neurofibrillary tangles (NFT), senile plaques (SP), granulovacuolar degeneration (GV) and Hirano bodies (HB). In the second half it is demonstrated that sera raised against the paired helical filaments (PHF) in NFT, and monoclonal antibodies to phosphorylated epitopes on neurofilament proteins, also stain structures within neuronal perikarya without PHFs in some diseases. These include Pick bodies and swollen cells in Pick's disease, neurons in old dogs without NFTs, and occasional neurons without NFT in AD. We conclude that PHF constituent proteins can be accumulated in neuronal perikarya of cases with these diseases without being actually assembled to PHFs. In AD and in the old dogs, such accumulations occurring without the formation of PHFs might represent a precursor state of the latter.