Collection of nucleus accumbens tissue
Twenty-four hours after the last ShA or LgA session, rats were decapitated without anesthesia, brains were collected, freshly frozen and stored at -80°C. Nucleus accumbens core (cNAc) and shell (sNAc) punches were collected from 220 um brain slices, as previously described (Giannotti et al., 2016). The punches were collected according to coordinates as described by Paxinos and Watson (from Bregma +2.76 to Bregma +0.84 mm) (Paxinos and Watson, 2007), using a punching needle with a diameter of 1 mm (Fig 1c). For both regions, the two hemispheres were pooled. Punches were stored at -80°C.