Figure 1.
(A) Example dendritic segment with spines. Time-lapse images (every 2 min) of nearby spines showing different kinds of motility – (1) change in position and shape (2) increase in length, (3) decrease in length, and (4) change in position. (B) Image acquisition protocol to study dynamics at two timescales. Each timepoint consists of five stacks, each separated from the next by 1 min. Timepoints themselves are T0, T1…, separated by hours. (C) Time-lapse images of example spine showing instantaneous length (Lt), average length (slow dynamics), and length motility (fast dynamics) measured at two timepoints. (D) Estimating the contribution of various sources of treatment-independent noise to the measurement of center-of-mass motility (CM motility, D1), change in average length (D2), and the contribution of treatment-dependent noise (D3). FRAP is fluorescence recovery after photobleaching. T0 (baseline) = −10 min, T1 = 75 min, and T2 = 180 min. The pseudo-coloring of dendrites and spines in all panels indicates the intensity of over-expressed EGFP, with white being the highest pixel intensity and black the lowest. All panels modified from Mysore et al. (2007).