Objective To identify the genetype of the PS1/APP double transgenic mouse model, then to analyse the histopathological changes in the brain and compare the differences between the transgenic mice models and Aβ_(1-40)-injected rats models of Alzheimer disease. Methods The modified congo red staining, Nissl's staining and immunohistology staining was used to observe the Aβ deposits, activation of astrocyte respectively. Results ①The PS1/APP transgenic mouse extensively displayed Aβ deposits in the cortex and hippocampal structures, and GFAP positive cells were aggregated in mass and surrounded the congo red-positive plaque. ②The Aβ_(1-40)-intrahippocampal-injected rat model showed the Aβ plaque deposits in the dentate gyrus of the hippocampus, with the astrocyte surrounded. The neurons loss was significant in the injection point and pin hole of injection with Nissl's staining methods. GFAP-positive cells increased significantly compared with the uninjected lateral of the hippocampus. Conclusion Although Aβ_(1-40)-injected rat models could simulate some characteristic pathological features of human Alzheimer diseases, Aβ deposits and neurons loss in partial hippocampal, it would not simulate the progressive degenenration in the brain of AD. The double transgenie PS1/APP mice could simulate the specific pathogenesis and progressive changes of AD, mainly is Aβ deposits and the spongiocyte response, while no neurons loss were observed in this model.
Da-Bing LIJun TANGXiao-Tang FANMin SONGHai-Wei XUYun BAI
