The distances of labels to the postsynaptic membrane were plotted as histograms. Under control conditions, the vertical distribution within the PSD complex is similar for Homer 1 (A), Homer 2 (B), and pan Shank (D). Upon high K+ depolarization, the distribution of Homer 1 did not change within the PSD complex (C). Statistical analysis was carried out with Kruskal-Wallis rank sum test (KaleidaGraph, Synergy Software, Reading, PA) with significance level set at P<0.05. None of the histograms was significantly different from each other.