The amplitude of spontaneous calcium transients was calculated by measuring the change in total pixel intensity for each normalized calcium transient trace. The rate was determined by dividing the total number of spontaneous calcium transients for any ROI by the total length of the movie (90 seconds). The synchronicity of spontaneous calcium transients was determined by two independent calculations. First, to determine the percentage synchronicity per calcium transient, the total number of synchronized calcium transients, defined as three or more simultaneous peaks, was divided by the total number of spontaneous calcium transients identified. Second, to calculate the maximum percentage synchronicity, the maximum number of ROIs involved in a single synchronized event was divided by the total number of ROIs identified.
