GCaMP6

GCaMP6 is a genetically encoded calcium indicator. It is a fusion protein consisting of a circularly permuted enhanced green fluorescent protein (cpEGFP) and a calmodulin-M13 peptide domain. When calcium ions bind to the calmodulin-M13 domain, it causes a conformational change that alters the fluorescence properties of the cpEGFP, leading to an increase in fluorescence intensity. This allows researchers to visualize and measure changes in intracellular calcium concentration in living cells and organisms.

Developed by the lab of Douglas Kim, GCaMP6 is a family of indicators that were engineered for improved performance compared to earlier GCaMP versions. The GCaMP6 family includes several variants, such as GCaMP6f, GCaMP6s, and GCaMP6m, which differ in their response kinetics, sensitivity, and brightness. These indicators can be expressed in specific cell types or across entire tissues using various genetic tools, including viral vectors and transgenic animal models.

GCaMP6 has become a widely adopted tool in neuroscience and other fields. Its applications include studying neuronal activity in real-time, mapping neural circuits, and investigating calcium signaling in a variety of biological processes. The indicators' ability to report on calcium dynamics with high temporal and spatial resolution has greatly advanced our understanding of cellular function and complex biological systems. Researchers often express GCaMP6 in neurons to monitor action potentials and synaptic activity.