AD models were established by using Aβ(1-42), Aβ(25-35) or Aβ(1-40) cerebral ventricle infusion (n = 7), using D-galactose (D-gal, n = 6), scopolamine (n = 6), sodium nitrite (n = 4), aluminium chloride (AlCl3, n = 2) or quinolinic acid (n = 1) intraperitoneal injection, or using SAMP8 mice (n = 2) and APP/PS1 transgenic mice (n = 1) directly. The gene discussed is PSEN1; the disease is Alzheimer disease.