Cytosolic, synthetic chemical calcium indicators are typically used to visualise the rapid increase in intracellular calcium ion concentration that follows nanosecond pulsed electric field (nsPEF) application. This study looks at the application of genetically encoded calcium indicators (GECIs) to investigate the spatiotemporal nature of nsPEF-induced calcium signals using fluorescent live cell imaging. Calcium responses to 44 kV/cm, 10 ns pulses were observed in U87-MG cells expressing either a plasma membrane targeted GECI (GCaMP5-G), or one cytosolically expressed (GCaMP6-S), and compared to the response of cells loaded with cytosolic or plasma membrane targeted chemical calcium indicators. Application of 100 pulses, to cells containing plasma membrane targeted indicators, revealed a wave of calcium across the cell initiating at the cathode side. A similar spatial wave was not observed with cytosolic indicators with mobile calcium buffering properties. The speed of the wave was related to pulse application frequency and it was not propagated by calcium induced calcium release.

胞质合成化学钙指示剂通常用于观察纳秒脉冲电场（nsPEF）应用后细胞内钙离子浓度的迅速增加。这项研究着眼于遗传编码钙指示剂（GECI）在使用荧光活细胞成像研究nsPEF诱导钙信号时空性质方面的应用。在表达质膜靶向GECI（GCaMP5-G）或一种细胞质表达（GCaMP6-S）的U87-MG细胞中，观察到钙对44 kV / cm，10 ns脉冲的响应，并将其与载有GFP的细胞的响应进行比较胞质或质膜靶向化学钙指标。向含有质膜靶向指示剂的细胞施加100个脉冲，揭示了从阴极侧开始穿过细胞的钙波。具有可移动钙缓冲特性的胞质指示剂未观察到类似的空间波。波的速度与脉冲的施加频率有关，并且不因钙诱导的钙释放而传播。