AMYLOID-BETA PROTEIN-1-42 43 (A-BETA-1-42/43) IN CEREBELLAR DIFFUSE PLAQUES - ENZYME-LINKED-IMMUNOSORBENT-ASSAY AND IMMUNOCYTOCHEMICAL STUDY/

Diffuse plaques are immature and amorphous senile plaques and believed to be in the initial phase of plaque formation. In contrast to amyloi d angiopathy and the plaque core amyloid, diffuse plaques failed to be purified in preserved forms from the brain. Here, we studied the diff use plaques in the cerebellar region of the Alzheimer's disease brain based on immunocytochemistry and ELISA using two different monoclonal antibodies specifically recognizing the carboxyl termini of A beta mol ecules (BA27 for A beta 1-40 and BC05 for A beta 1-42/43). We found th at the amount of A beta 1-40 was in proportion to the staining degree on amyloid angiopathy by immunohistochemistry. We found that A beta 1- 42/43 comprised diffuse plaques as the major component in the cerebell a of AD brains. Taking these findings into consideration, diffuse plaq ues, the earliest pathological change in the brain with AD, are conclu ded to be composed mainly of A beta 1-42/43, implicating the critical importance of this kind of A beta species deposition in the pathogenes is of AD.