The 250 μm-tick sections containing injected striatal neurons were mounted on glass slides and coverslipped with a fluorescence mounting medium (S3023; Dako, Mississauga, Ontario, Canada). Z-stack of Lucifer yellow-filled neurons were obtained from the confocal microscope using a 405 nm diode laser and a 63x oil immersion objective (NA 1.4, Plan-Apochromat, Zeiss). The pixel size was 0.001 μm2 whereas the optical slicing was 0.3 μm. A tiling process was used when dendritic arborization extend beyond the field of view.
