The tau gene is one of the target genes regulated by CREB, and downregulation of the PKA/CREB signalling pathway can lead to learning and memory defects in patients with AD and in mice (Puzzo et al. 2005; Yamamoto-Sasaki et al. 1999; Matsuzaki et al. 2006; Liang et al. 2007). This evidence concerns the gene MAPT and Alzheimer disease.