MAPT and Alzheimer disease: In the current study, oral administration of AlCl3 for 4 successive weeks resulted in a prominent elevation (p < 0.0001) in the hippocampal levels of tau (163.80 ± 4.26) and β-secretase (1.75 ± 0.03), the hallmarks of AD, with a significant (p < 0.0001) downregulation of CREB (0.57 ± 0.04) in comparison with the normal group (38.70 ± 2.97, 0.55 ± 0.1, 1.97 ± 0.12) for tau, β-secretase, and CREB, respectively.