Finally, while previous studies have frequently reported spontaneous seizures and epileptiform activity in AD mice (Lalonde et al., 2005; Minkeviciene et al., 2009), and EEG recordings confirm increased epileptiform activity in our APP/PS1 mouse strain as well (unpublished data), our current study lacks direct observational data to support this claim. This evidence concerns the gene PSEN1 and Alzheimer disease.