Intracellular Calcium Measurements for Functional Characterization of Neuronal Phenotypes

The central and peripheral nervous system is built by a network of many different neuronal phenotypes together with glial and other supporting cells. The repertoire of expressed receptors and secreted neurotransmitters and neuromodulators are unique for each single neuron leading to intracellular signaling cascades, many of them involving intracellular calcium signaling. Here we suggest the use of calcium signaling analysis upon specific agonist application to reliably identify neuronal phenotypes, being important not only for basic science, but also providing a reliable tool for functional characterization of cells prior to transplantation. Calcium imaging provides various cellular information including signaling amplitudes, cell localization, duration, and frequency. Microfluorimetry reveals a signal summarizing the entire population, and its use is indicated for high-throughput screening purposes.