Objective       To investigate the function of GCaMP (a genetically encoded calcium indicator) engineered C17.2 neural stem cells in calcium imaging.       Methods       C17.2-GCaMP cells were generated from C17.2 cells by infection of the lentivirus carrying GCaMP gene. Real-time PCR was applied to test the expression of nestin (the marker of neural stem cells) between C17.2 cells and C17.2-GCaMP cells. The calcium imaging of C17.2 cells loaded with Fluo-4 AM and C17.2-GCaMP cells was recorded under customerized digital fluorescence microscope.       Results       Real-time PCR results revealed that there was no significant difference in the expression of nestin between C17.2 cells and C17.2-GCaMP cells (P0.05). The calcium spikes in the C17.2-GCaMP cells had longer duration and higher intensity than those in C17.2 cells loaded with Fluo-4 AM (P0.05). In addition

typical calcium waves were observed in Fluo-4 AM-loaded C17.2 cells but not in C17.2-GCaMP cells.       Conclusion       C17.2-GCaMP cells maintain their stemness of neural stem cells after gene modification

and are able to instantly monitor the intracellular calcium dynamics

which could be applied to investigate the functional integration of transplanted neural stem cells in vivo.