A synapse perspective on the function of the amyloid precursor protein.

The amyloid precursor protein (APP) is a transmembrane protein widely expressed throughout the brain, where it plays critical roles in both physiological and pathological states. APP undergoes complex post-translational processing by various secretases, a process that can lead to amyloid plaque formation via its amyloidogenic pathway. Consequently, APP has been extensively studied in the context of Alzheimer's disease (AD). However, emerging evidence highlights its physiological functions and the diverse roles of its cleavage fragments. This review explores the dual role of APP and its fragments, focusing on their contributions to synaptic structure, function, and plasticity. We summarize the mechanisms by which APP and its fragments influence synaptic dynamics and plasticity in the hippocampal CA1 region. These insights underline the importance of APP beyond amyloidogenesis, emphasizing its role in fundamental neurobiological processes and potential implications for understanding early AD-related synaptic dysfunction.