Figure 5. Single D1 receptor tracking in acute brain slices.

(a–b) Rats were electroporated in utero with D1-CFP and EGFP constructs and electroporated pups were injected with QD to recognize the CFP epitope in transfected neurons. Acute brain slices of electroporated animals injected with functionalized QD were imaged in a spinning disk confocal microscope (b) (scale bar, 15 μm). (c) Fast two-dimensional imaging was performed over transfected neurons with coupled QD and subsequently QD were identified and trajectories reconstructed (scale bar, 10 μm). (d) Example trajectories with the calculated mean squared displacement. (e) A comparison between the diffusion of QD in spines and dendrites shows that the calculated coefficients are slower for spines (n=212 trajectories along spines, n=2,193 trajectories along dendrites).