AD C+S: Alzheimer's context + shock: Alzheimer's mice were 50% C57BL/6, 50% SJL. Alzheimers animals were the double transgenic models reported by Dineley et al., (2002) J Biol Chem 277(25):22768-22780. Alzheimer's mice were exposed to a contextual fear conditioning paradigm that consisted of: Placement into a novel spatial context for 2 min. After 2 min, a 1 sec (0.5 mA) shock was administered through a floor grid. The 2 min-1 sec shock paradigm was repeated for a total of 3 shocks. 1 min after the last shock, animals were removed to their homecage. RNA was extracted was extracted 2 hours after the last shock treatment.