Alzheimer’s disease is a progressive neuro- degenerative disorder characterized by the presence of senile plaques primarily composed of amyloid β in brain. Abnor- mal secretion and aggregation of amyloid β are the key events in pathogenesis of Alzheimer’s disease. Reduction of amyloid β production and inhibition of amyloid β aggrega- tion to form senile plaques are hopeful strategies for the treatment and prevention of Alzheimer’s disease. In the pre- sent study, the silver and immunohistochemical staining methods were applied to discover senile plaques in the hip- pocampus of Alzheimer’s disease patients, and then images were processed and three-dimensionally reconstructed by Matlab and AVS software. The structure characteristics of senile plaques were measured through correlation function calculation and fractal dimension by a computer-aided method. Diffuse plaque had no amyloid center, but classic plaque presented compact central core structure; two types of plaques were both of porous structure, but the sizes of their pores were significantly different. Furthermore, there was difference in fractal dimension value between the diffuse plaque and classic plaque in the two staining methods. The comparison of structure characteristics between two types of plaques indicated that they developed independently. Estab- lishment of the methods for reconstructing the three-dimen- sional structure of senile plaque and analyzing their struc- ture characteristics is helpful for further study on the aggre- gation mechanism of senile plaque.
