GCaMP, a Family of Single-Fluorophore Genetically Encoded Calcium Indicators

Single-fluorophore genetically encoded calcium indicators (GECIs), such as GCaMP, are widely used tools to investigate neuronal activity. Their primary advantage lies in their capability to provide real-time and highly sensitive responses to fluctuations in intracellular Ca2+ concentrations. This property is of particular importance when studying neuronal processes and ensembles wherein calcium signals play a crucial role in information transmission. This comprehensive review focuses on the GCaMP family, encompassing an analysis of their various types, distinctive features, and potential applications for visualizing neuronal activity. Special attention is given to the ongoing advancements in GCaMP technology, specifically, the endeavors to expand their spectral properties and enhance their capability to detect high-frequency spike activity.