Conditional dendritic targeting dependent on influx of Ca2+ through VDCCs. (A and B) ID4-chimeric α-tubulin mRNA was delivered to dendrites of sympathetic neurons after β-adrenergic activation. (C–F) Dendritic transport was significantly reduced if β-adrenergic activation occurred in the presence of L-type VDCC blocker nimodipine (C and D) or nifedipine (E and F). Number of cells analyzed: (A and B) 16 cells, 57 dendrites; (C and D) 19 cells, 80 dendrites; (E and F) 20 cells, 78 dendrites. Bar, 50 µm. (G) Quantitative analysis. One-way ANOVA, Dunnett’s post hoc analysis (comparison of RNA levels after β-adrenergic activation with RNA levels after β-adrenergic activation in the presence of nimodipine or nifedipine): comparison with nimodipine (C and D), P < 0.001 for all interval points; comparison with nifedipine (E and F), P < 0.01 for all interval points. Error bars indicate SEM.
