Overview of GCaMP calcium indictors (IMAGE) Howard Hughes Medical Institute Caption Overview of GCaMP calcium indictors for neuronal imaging. When they sense calcium, GCaMP indicators cause neurons to produce green fluorescent light, allowing scientists to see which neurons and synapses are activated in living animals as they perform a task. Credit Yan Zhang Usage Restrictions Please use caption and credit provided License Original content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.