Animals and study approval

Procedures involving animals and their care were conducted in conformity with the Italian Guidelines for Laboratory Animals, which conform to the European Communities Directive of September 2010 (2010/63/UE) and the Review Committee of the University of Milan gave its approval to the study (N° 778/2017). Male C57BL/6 mice (Charles River, Milan, Italy), 12-16 weeks old and weighing 20-24 g were kept for at least 7 days before the experiments in standard conditions (22 ± 2 °C, 65% humidity, and a 12h light-dark cycle) with food and water ad libitum. Moreover, in order to make them amenable the animals were accustomed to the behavioral tests (horizontal and vertical, see below for details) daily for one week prior to 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) i.p. injection.