2.1. Subjects
Male Swiss CD-1 mice (Charles River, Lyon, France) weighing 25–30 g (8 weeks-old) were randomly assigned to an experimental group and used for the behavioural experiments. The CD1 mouse strain was selected for its optimal sensitivity to the psychostimulant effects of cocaine (McKerchar et al., 2005). For the synaptosomal preparation, male Sprague-Dawley rats (Janvier, Le Genest, France) weighing 225–250 g (2-3 months-old) were used. This rat strain has been used widely to obtain pure rat brain synaptosomes (Kolanos et al., 2015; Gannon et al., 2018; Lopez-Arnau et al., 2019; Saha et al., 2019). The animals were housed in temperature-controlled conditions (22 ± 1°C) under a 12 h light/dark cycle and had free access to food (standard laboratory diet, Panlab SL, Barcelona, Spain) and drinking water. All animal care and experimental protocols in this study complied with the guidelines of the European Community Council (2010/62/EU) and were approved by the Animal Ethics Committee of the University of Barcelona under the supervision of the Autonomous Government of Catalonia. Efforts were made to minimize suffering and reduce the number of used animals. All studies involving animals are reported in accordance with the ARRIVE and BJP guidelines for reporting experiments involving animals (McGrath and Lilley, 2015).