Effects of long term high cholesterol diet on spatial learning in aged rats

Aims: The present study aimed to determine the effect of a long-term cholesterol enriched diet on spatial learning performance in middle to old aged rats. Materials and methods: Based on initial Morris water maze results, 40 female SD rats aged 12-month were screened and randomly divided into 2 groups. Two groups of female SD rats were fed either a balanced diet or a high cholesterol diet for 6 months on their 12-month aged of life (n=20 per group). At the end of the dietary intervention, behavioral testing by the Morris water maze task was applied again at 18 months to evaluate the spatial learning of aged rats by measuring latency, compared to controls. Results: Consumption of a long term high cholesterol diet for 6 months significantly elevated serum cholesterol levels reported to controls. During the transition period from middle age to old age, rats fed with cholesterol enriched diet exhibited a longer escape latency than that of control group. Conclusion: Our findings provided evidence that a long-term cholesterol-treated rats impaired aged rats’ spatial learning.