CREB1 and Parkinson disease: Recently, it was demonstrated that quercetin improved mitochondrial biogenesis and induced the activation of two major cell survival kinases, PKD1, and Akt and also enhanced CREB and BDNF (a CREB target gene) in MN9D cells against 6-OHDA-induced neurotoxicity, and in the MitoPark transgenic mouse model of PD, quercetin improved behavioural deficits and reduced TH cell loss [47].