Our present study demonstrated that, following a 21-day sleep restriction, the wild-type 12-month-old C57BL/6 female mice developed AD accompanied by cognitive deficiency, Aβ deposition and tau hyper-phosphorylation in the hippocampus, but these phenomenons can be reversed when treated with KD, indicating the prophylactic effect of KD on SD induced AD. The gene discussed is MAPT; the disease is Alzheimer disease.