Acute effect of β amyloid on synchronized spontaneous Ca2+ oscillations in cultured hippocampal networks

The effects of beta amyloid (A beta) on cytoplasmic Ca2+ ([Ca2+](c)) have been studied extensively, but the current literature on this aspect is confusing. We reported that 20 mu M A beta(25-35) significantly inhibited the synchronized spontaneous cytoplasmic Ca2+ transients immediately after application, whereas it had little effect on the baseline [Ca2+](c) concentration in neurons. A beta(1-42) had a similar effect on the Ca2+ transients as A beta(25-35), while it increased baseline [Ca2+](c) concentration gradually. However, A beta(1-40) had little effect on either Ca2+ transients or baseline [Ca2+](c). Such differential effects of A beta on Ca2+ signals might explain, at least partially, the confusing observations from the previous studies and provide important therapeutic implications for preventing or reversing early neuron damage in Alzheimer's disease. (c) 2006 International Federation for Cell Biology. Published by Elsevier Ltd. All rights reserved.