FIGURE 4.

NMDAR stimulation increases PICK1 dimerization in neurons. DIV17-18 neurons expressing ^mGFPPICK1 alone, ^mGFPPICK1 and free mCherry, or ^mGFPPICK1 and ^mCherryPICK1 were stimulated with 30 μM NMDA or vehicle for 3 min, followed by fixation immediately after stimulation or 5 min after removal of NMDA. The lifetime decay of GFP was fitted (see the “Materials and methods” section) and the representative intensity merged, fluorescence lifetime images of neuronal dendrites are shown. Red color corresponds to short lifetime, therefore high FRET and increased PICK1 dimerization. The colored bar on the right-hand side represents the lifetime of mGFP ranging from 2,240 ps (red) to 2,700 ps (blue). The lifetime signal is intensity-adjusted and the scale bar is consistent between panels at 5 μm. The graph shows mean recorded lifetimes; n = 15 cells from five independent experiments, *p < 0.05, one-way ANOVA.