Amyloid beta mediates memory formation

The amyloid precursor protein (APP) undergoes sequential cleavages to generate various polypeptides, including the amyloid beta (1-42) peptide (A beta[1-42]), which is believed to play a major role in amyloid plaque formation in Alzheimer's disease (AD). Here we provide evidence that, in contrast with its pathological role when accumulated, endogenous Ab in normal hippocampi mediates learning and memory formation. Furthermore, hippocampal injection of picomolar concentrations of exogenous A beta(1-42) enhances memory consolidation. Correlative data suggest that Ab peptides may exert their function via nicotinic acethylcoline receptors. Hence, Ab peptides, including A beta(1-42), play an important physiological role in hippocampal memory formation.