CaSA software flow chart. The chart resumes the main computational tasks performed by CaSA software. The required input data sets are the control and treatment time series files (see Supplementary Materials). All data are filtered for noise and a first analysis of the treatment series is made to detect putative peaks. Similarly, false positive peaks are identified in the control and used to characterize low-level oscillations that will be considered as noise. Putative peaks with such characteristics are then removed from the treatment time series. The software then computes the number of remaining peaks in each sample and measures the waiting times between adjacent peaks. All output data are presented in a text file that also contains basic statistical analyses, including the average peak number, the average waiting time and the number of samples where spiking can be detected. Lastly, PNG image files are generated presenting the plots of the original ratiometric data, the filtered trace, and indications of the detected peaks.