Magnetic field exposure saves rat cerebellar granule neurons from apoptosis in vitro

Accumulating evidence demonstrates that extremely low frequency magnetic fields (ELF-MFs) are capable of modifying neuronal function. Here we examine the effect of ELF-MF exposure on neuronal apoptosis. For this purpose cerebellar granule neurons (CGNs) from postnatal rats were employed, which are known to undergo apoptosis under normal condition (5.4 mM K+) in vitro. Exposure to a rotating (50 Hz) ELF-MF for 5 days saved immature CGNs from apoptosis and promoted survival at the flux density of 300 mT, whereas virtually no neuronal survival was observed without exposure (sham). The survival-promoting effect of ELF-MFs occurred in a manner that depended on the size of culture flasks, suggesting that induced current plays a role in this phenomenon. A maximal survival-promoting effect was comparable to that of membrane depolarization (25 mM K+) and greater than that of brain-derived neurotrophic factor (BDNF). These results imply that ELF-MFs may serve as a potential tool for manipulating neuronal death and/or survival.