Neuronal calcium imaging technology is an important tool in current neuroscience research. The technology is based on the tight relationship between calcium ion concentration and neuronal activity, and converts changes in calcium ion concentration into changes in fluorescence intensity using special fluorescent dyes or protein fluorescent probes.

To characterize the development of neuronal activity, intracellular calcium levels were measured using Fluo-4 AM and Fura-2 AM. This was done to assess the changes in intracellular calcium transients during in vitro development.