Under isofluorane anaesthesia, mice were implanted with microdialysis probes as previously described 38, aimed at the nucleus accumbens (NAc), and secured to the skull using a skull screw and cement. Histologically verified placement within the NAc for each subject is shown in Figure 3A. During a 12h postsurgical recovery period, probes were slowly perfused with artificial cerebrospinal fluid. The perfusion flow rate was then increased to 0.6µL/min for 2h to reach an interstitial equilibrium before sample collection. Dialysate fractions were subsequently collected, during the dark cycle, at 10min intervals during a 60min baseline period and, after an injection of EtOH (2g/kg, ip), during a 120min post-injection period. Samples were analyzed for DA and 5-HT using high-performance liquid chromatography coupled with electrochemical detection (HPLC-ECD).
