FIG. 4.

Translocation of SK1 during depolarization. Hippocampal neurons were transiently transfected with expression vectors encoding GFP-SK1, free GFP, or SynPhy-GFP as indicated. Two days after transfection living cells were subjected to FRAP analysis using confocal laser scanning microscopy. After depolarization induced either by 50 mM KCl (A) or 100 μM glutamate (B), axonal puncta expressing GFP-fused proteins were photobleached. Subsequently, images were collected at the indicated time points. For the graphs the fluorescence recovery immediately after photobleaching (lowest fluorescence intensity, 0 s) at each punctum of interest was measured and is given as percent fluorescence recovery based on the initial value before bleaching. Data are means ± standard errors of the means of three independent experiments carried out in triplicate.