ARGYROPHILIC STRUCTURES STIMULATE GLIAL REACTIONS IN NEUROFIBRILLARY TANGLES AND SENILE PLAQUES

Neurofibrillary tangles (NFT) and senile plaques (SP) contain various pathological structures, and the majority of these pathological struct ures are argyrophilic. To investigate the glial reactions of the argyr ophilic substance, we performed immunohistochemistry fbr microglia or for astroglia after Gallyas-Braak staining, which is one of the most s ensitive silver impregnation techniques detecting argyrophilic structu res in NFT and SP. We found that extracellular argyrophilic structures in NFT and SP showed glial reactions, and we observed reactive microg lia in the center of NFT and SP in contrast to astroglia, which were s ituated in the periphery. These findings suggest that the exposed argy rophilic components in the extracellular space stimulate both glial re actions, but that there is a striking difference in localization betwe en microglia and astroglia.