Fifty-six days after the 6-OHDA lesion, animals were deeply anesthetized with a mixture of ketamine (100 mg/kg) and xylazine (10 mg/kg). They were transcardially perfused with an initial wash of 40 mL of ice-cold sodium phosphate-buffered saline (PBS, 0.1 M; pH 7.4), followed by 150 mL of paraformaldehyde (PFA, 4% diluted in phosphate buffer). Brains were dissected out, post-fixed for 24 h in a 4% PFA solution and cut with a vibratome (model VT1200; Leica, Germany) into 50 μm-thick coronal sections, which were serially collected in sodium phosphate-buffered saline (PBS, 0.1 M, pH 7.4). The pre and post-commissural parts of the striatum were cut at 50 μm and used for immunohistochemistry and stereology whereas the commissural part was cut at 250 μm for intracellular injections.
