Impaired Pavlovian cued fear conditioning in Tg2576 mice expressing a human mutant amyloid precursor protein gene

The processing of emotional and/or fear-related events is abnormal in patients with Alzheimer's disease. AD is accompanied by a number of neuropathological features, one of which is the deposition of amyloid plaques. The main aim of the present study was to examine the effects of a human amyloid precursor protein mutation on both the acquisition and expression of fear conditioning in Tg2576 mice. Sixteen-month-old, but not 4-month-old, transgenic mice showed aberrations in post-shock freezing during training. In a retention test carried out 241 It after training, Tg2576 mice showed comparable levels of conditioned fear elicited by contextual cues. However. freezing elicited by a tone conditioned stimulus was impaired in 16-month-old but not 4-month-old Tg2576 truce. The results are discussed with reference to the role of Cue competition (overshadowing) in revealing fear conditioning deficits in Tg2576 mice. (C) 2004 Elsevier B.V. All rights reserved.