Fig. 1. The physiological roles of amyloid-β (Aβ). (a) Aβ has an antimicrobial property: Aβ induces agglutination and inhibits the adhesion of pathogens to host cells. (b) Aβ regulates synaptic functions: picomolar concentrations of Aβ42 increase the concentration of acetylcholine (ACh), by acting as an allosteric enhancer of choline acetyltransferase (ChAT), causing an influx of Ca2+ through α7-nicotinic acetylcholine receptors (α7-nAChRs), which eventually lead to an increase in long-term potentiation (LTP). (c) Aβ promotes recovery from brain injury: during the recovery of traumatic brain injury (TBI), the levels of Aβ elevate, hinting a protective role of Aβ against brain injury. (d) Aβ serves as a sealant of blood-brain barrier (BBB) leakages. (e) Monomeric forms of Aβ dose-dependently promote angiogenesis. (f) Aβ suppresses tumor growth by promoting apoptosis.
© Exp Neurobiol
