Entropy: A way to quantify complexity in calcium dynamics

Abstract

Ca2+ is an intracellular signal that can regulate many cellular functions. It is at the basis of the communication of different cellular populations, as astrocytes. Astrocytes are cells of the brain endowed with supportive functions towards neurons. They also regulate and control neuronal activity. In this paper, we employed Shannon entropy to quantify the complexity of calcium dynamics in astrocyte cultures. We exploited astrocyte fluorescence recordings, reporting calcium activity before and after Ionomycin stimulation. The use of an original algorithm for the construction of Entropy Maps al-lowed us to infer the non-linear characteristics of calcium dynamics. The implemented method highlights a different level of complexity in the behavior of the nucleus, if compared to the surrounding compartments. Moreover the wave spreading modifies the unpredictability of calcium activity in the culture. © 2010 International Federation for Medical and Biological Engineering.