Calcium is involved in NRG1-induced migration. A: Representative images of migrated ErbB4-transfected cells in the presence/absence of 15 μM BAPTA-AM, showing that both NRG1- and (NRG1+NMDA)-induced migrations are reduced by buffering of intracellular Ca2+. Cells were treated for 18 hrs with 8 μM NMDA, 5 nM NRG1 or both. B: Histogram of the same migration assay. Migration was calculated as percentage of total migrated cells as described in Material and Methods. Biological triplicate experiments were carried out in technical triplicate. Data are presented as means + SD. Statistical analysis was performed by applying two-way ANOVA, followed by Tukey's posthoc test (see text for details) * = p < 0.05; ** = p < 0.01; *** = p < 0.001.