Histograms of distance measurements of labels for Shank 1 and Shank 2 under different experimental conditions.

Sister cultures were labeled with antibodies against either Shank 1 (left) or Shank 2 (right) after identical experimental manipulations and processed in parallel. For each Shank isoform, the differences between control and high K⁺ or control and EGTA are statistically significant (Wilcoxon ran-sum test; same data set as exp 3 in Table 4).