【Animal modeling】-Pathological changes of amyloidosis and cerebrovascular disease in Alzheimer's disease rats

  Objective: To investigate the pathological changes of brain tissue of amyloidosis cerebrovascular lesions on the basis of establishing an experimental rat model of Alzheimer's disease.

  Methods: Aβ1-42 fibers were injected into the bilateral hippocampus of rats under the guidance of a stereotaxic instrument to establish an animal model of Alzheimer's disease. The water maze test was used to evaluate the higher cognitive function of the rats. Staining and α-actin, Aβ double-labeled immunofluorescence staining were used to observe the dynamic changes of amyloid deposition in the rat brain and amyloidosis cerebrovascular lesions.

  RESULTS: Compared with the sham-operated control group, the escape latency time and the number of platform explorations were significantly different between the model group and the sham-operated control group. HE staining showed that the granulosa cells in the hippocampus of the model group were reduced, cell degeneration, gliocyte proliferation, and degeneration of the small blood vessel walls in the hippocampus. Congo red staining showed that Aβ fibers gradually deposited in the walls of small blood vessels, the walls were thickened, and the small blood vessels were narrowed or occluded; immunofluorescence staining showed that Aβ fibers in the brain tissue of the model group gradually migrated to small arteries.

  Conclusion: Amyloid cerebrovascular lesions are the main pathological changes of Alzheimer's disease.