APP and Alzheimer disease: This finding is also consistent with the observation that the presence of APP is likely to contribute to hippocampal hyperactivity, which has been suggested as a key mechanism of disease etiopathogenesis both in AD animal models and patients (Bakker et al., 2012; Busche et al., 2012; Palop et al., 2007; Verret et al., 2012; Vossel et al., 2013).