Analysis of AChR and α-DG label correlations for the stimulus protocols. The stimulus protocols for all panels are shown at the bottom: C control (no stimulus), A agrin, L laminin-1, AL agrin and laminin. Red bars, raw data correlation. Green bars, high frequency correlation (see Figure 7, Materials and Methods). Blue bars, above threshold correlation. The latter two metrics (green and blue) are the most relevant to the question of molecular aggregation, and show little if any correlation under control conditions. All metrics show progressive and significant increases as the stimulus protocol is changed to agrin, LN1, and agrin with LN1.