Images were collected at 15 Hz (512 × 512 pixels, 250 μm × 250 μm; Fig. 2) or 60 Hz (256 × 256 pixels, 30 μm × 30 μm; Fig. 3), or 15 Hz (512 × 512 pixels, 30 μm × 30 μm; Fig. 4-5), or 15 Hz (512 × 512 pixels, 30 μm × 30 μm - 100 μm × 100 μm; Fig. 6). For dendritic imaging experiments (Fig. 4-6), fields of view were chosen so that extended dendritic segments were in one focal plane. At the end of each imaging session, z-stacks (1 μm step size) of the recorded cells were acquired. The coordinates of the imaged dendrites relative to the parent somata were recorded. The orientation, curvature, and the branching pattern of the dendrites together with the constellation of spines, helped to precisely identify the same field of view in long-term imaging experiments.
