Amyloid beta-peptide: Biphasic dose responses

This article summarizes recent findings indicating that amyloid beta -pepti de displays neurotoxic and neurotrophic effects, depending on concentration . Mechanistic findings revealed that reactive oxygen species mediate both t he toxic and neurotropic responses as a function of concentration with low doses being neutotrophic,while higher doses were toxic. The data reveal a p otential biological function for amyloid beta -peptide within an optimal co ncentration zone. These findings suggest the critical role of dose in under standing disease causation and clinical therapeutics for Alzheimer's diseas e.