BDNF and Cognitive impairment: Interestingly, by utilizing a murine transgenic model of DS carrying an extra copy of DYRK1A (a candidate gene for DS), which displays both brain abnormalities and learning impairment, Guedj et al. [89] demonstrated that the overexpression of DYRK1A was responsible for the decrease in BDNF: transgenic mice fed with the DYRK1A inhibitor epigallocatechin gallate (EGCG)—a member of a natural polyphenols family from green tea—increased BDNF expression and partially rescued cognitive deficits.