Acquisition of conditioned taste aversion is impaired in the amyloid precursor protein/presenilin 1 mouse model of Alzheimer's disease.

Research into the underlying mechanisms of cognitive dysfunction in Alzheimer's disease (AD) has relied traditionally on tasks such as the water maze which evaluate spatial learning and memory. Since non-spatial forms of memory are also disrupted by AD, it is critical to establish other paradigms capable of investigating these deficits. Utilizing a non-spatial learning task, acquisition of conditioned taste aversion (CTA) was evaluated in a mouse model of AD. This line of transgenic mice encode a mutated allele of the human amyloid precursor protein (APP) and presenilin 1 (PS1) genes and exhibit extensive amyloid plaque deposition in the brain by 6-7 mo of age. Compared with wild-type mice, 10-17 month old APP/PS1 mice failed to acquire CTA to saccharin. Mice that only possessed one of the two mutations were able to acquire CTA to the saccharin. In 2-5 month old APP/PS1 mice acquisition of CTA was disrupted despite the lack of extensive plaque deposition. However, further analysis indicated a potential gender difference in both the CTA deficit and onset of plaque deposition with females showing greater conditioned aversion.