Since the hippocampus is among the earliest brain areas to be affected in AD (Braak and Braak, 1991) and is a key brain region in episodic learning and memory consolidation (McClelland et al., 1995), we assessed the impact of primary-preventive BACE1-inhibition on hippocampal dendritic spine dynamics in an amyloid mouse model. This evidence concerns the gene BACE1 and Alzheimer disease.