FIG. 3.

Involvement of SK1 in depolarization-evoked secretion. (A) Rat hippocampal neurons were transfected either with control or rSK1-siRNA together with expression vectors encoding rSK1, hSK1, or hSK1G82D. Two days after transfection neurons were analyzed for SK1 expression by immunoblot analysis. Endogenous SK1 mRNA and protein were quantitated in neurons transfected with either control or rSK1-siRNA by real-time quantitative PCR (B) or by immunoblot analysis using anti-SK1 antibody (C). Neurons transfected with either control or rSK1-siRNA together with vectors encoding hSK1, hSK1G82D, or an empty vector (mock) were prelabeled with FM4-64 and treated with 50 mM KCl (D) or 100 μM glutamate (E), and the fluorescence of the dye at each punctum of interest was sequentially monitored. The arrow indicates the addition of glutamate. Data are means ± standard errors of the means of three independent experiments carried out in triplicate (D and E). For F(t), fluorescence at the selected region at time t, see text.