Physiological Roles of beta-amyloid in Regulating Synaptic Function: Implications for AD Pathophysiology

The physiological functions of endogenous amyloid-beta (A beta), which plays important role in the pathology of Alzheimer's disease (AD), have not been paid enough attention. Here, we review the multiple physiological effects of A beta, particularly in regulating synaptic transmission, and the possible mechanisms, in order to decipher the real characters of A beta under both physiological and pathological conditions. Some worthy studies have shown that the deprivation of endogenous A beta gives rise to synaptic dysfunction and cognitive deficiency, while the moderate elevation of this peptide enhances long term potentiation and leads to neuronal hyperexcitability. In this review, we provide a new view for understanding the role of A beta in AD pathophysiology from the perspective of physiological meaning.