GECIquant: Semi-automated Detection and Quantification of Astrocyte Intracellular Ca 2+ Signals Monitored with GCaMP6f

Astrocytes display diverse and frequent intracellular Ca2+ fluctuations that are separable by virtue of their location within the cells, their magnitude, and their duration. Recently, the study of astrocyte Ca2+ signaling has rapidly advanced by the availability of genetically encoded Ca2+ indicators (GECIs) such as GCaMP3 and GCaMP6. The systematic use of GECIs is beginning to reveal the rules for astrocyte engagement within neural circuits in brain slices and in vivo. However, the richness and high numbers of Ca2+ signals that have been observed necessitate their routine detection within the complex morphology of astrocytes. To this end, in this chapter, we describe the development and features of GECIquant software that permits the semi-automated detection and quantification of astrocyte Ca2+ signals. Biological insights afforded by the use of GECIs and GECIquant are also described.