Fluctuations in nuclear envelope's potential mediate synchronization of early neural activity

Neural progenitor cells and developing neurons show periodic, synchronous Ca(2+) rises even before synapse formation, and the origin of the synchronous activity remains unknown. Here, fluorescence measurement revealed that the membrane potential of the nuclear envelope, which forms an intracellular Ca(2+) store, changed with a release of Ca(2+) and generated spontaneous, periodic bursts of fluctuations in potential. Furthermore, changes in the nuclear envelope's potential underlay spike burst generations. These results support the model that voltage fluctuations of the nuclear envelope synchronize Ca(2+) release between cells and also function as a current noise generator to cause synchronous burst discharges. (C) 2011 Elsevier Inc. All rights reserved.