On each section, the striatum was entirely scanned through multiple Z-stacks using a 40x objective (NA 1.4, oil immersion, Plan-Apochromat, Zeiss) and the 488 and 568 diode lasers at 2% of power. Optical resolution of the Z-stacks was 512 × 512 pixel (pixel size = 0.10 μm2), with Z-steps of 3 μm corresponding to the optical slice determined by the pinhole. The thickness of Z-stacks was fixed at 30 μm and the gain setting for each channel was kept constant during the entire acquisition process.
