The results of the Y-maze spontaneous alternation task showed that compared to C57BL/6 J mice, APP/PS1 mice had significantly decreased latency to find the novel arm, meanwhile the spontaneous alternation rate in the AD-S group was significantly lower than that in the WT-S group, indicating impaired learning and memory abilities in APP/PS1 mice, leading to prolonged time to find the novel arm and decreased alternation between arms. The gene discussed is PSEN1; the disease is Alzheimer disease.