APP and Dravet syndrome: The Ts65Dn mouse model of DS exhibits raised App mRNA levels in the brain from 4-months (Holtzman et al., 1996), but raised levels of full-length APP (FL-APP) and Aβ have been primarily detected in the older Ts65Dn brain in an aging dependant manner, with increases in the hippocampus and cortex seen from 10-months of age (Hunter et al., 2003b; Choi et al., 2009; Illouz et al., 2019; Tallino et al., 2022).