OBJECTIVETo examine cerebral pathologies in cerebral amyloid angiopathy in a rat model of Alzheimer's disease.

METHODSRat models of Alzheimer's disease was established by stereotactic Aβ1-42 fiber injection in the bilateral hippocampus. The cognitive function of the rats was evaluated with water maze test. HE staining, Congo red staining and double-labeling indirect immunofluorescence were used to examine the dynamic distribution of Aβ fiber deposit in the brain.

RESULTSThe model rats showed significant differences from the control rats in the escape latency and the times of crossing platform in waster maze test. HE staining revealed a decreased number and degeneration of the granular cells with increased glial cells in the model rats. Congo Red staining showed that the Aβ fiber was deposited gradually in the small vessels in the brain parenchyma to cause thickening, stenosis or occlusion of the small vessels. Immunofluorescence staining detected Aβ fiber migration from the parenchyma to the walls of the small arteries in the rat models.

CONCLUSIONCerebral amyloid angiopathy is a major pathological feature in Alzheimer's disease.