Abstract: Objective Tg2576 transgenic mice with C57BL/6 and SJL hybridization background, which are commonly used in research of Alzheimer’s disease (AD), were used to investigate the potential effect of long-term breeding on the phenotype of AD. Methods Utilizing Morris water maze, immunohistochemistry, ELISA and immunofluorescence, the behavior and pathological phenotype of AD were studied in these Tg2576 mice which were introduced and bred in our laboratory for a long time. Results With the age increase, the learning and memory ability of in these Tg2576 mice was still significantly decreased. The typical beta amyloid (Aβ) deposition was also found in the cerebral cortex of these mice by immunohistochemistry. The content of Aβ in brain tissue was significantly higher than that in control mice. In addtion, the immunofluorescence analysis indicated that a large number of astrocytes gathered around Aβ plaques in the cerebral cortex. Conclusion The long-term bred of Tg2576 mice still have the typical clinical and pathological characteristics of AD mice.

Key words: Tg2576 mice, Alzheimer's disease (AD), Genetic background, Aβ plaque, Astrocyte