2.4.2 In vivo microdialysis

Rats were deeply anesthetized with isoflurane (Vaporizer Drager model 19.3, Germany, and pump air, model HAILEA ACO-208, China). Animals were anesthetized for surgery and during the microdialysis procedure, using 3% isoflurane and 1.5 mL/min of air for 10 min were used for induction. During microdialysis, maintenance was done in 1.5% isoflurane and 1.5 mL/min air for males and in 1.2% isoflurane and 1.5 mL/min air for females. The animals were placed in a stereotaxic apparatus, and their body temperature was maintained at 37°C with an electric blanket controlled by a thermostat. According to the experiment, a concentric cerebral microdialysis probe (Microdialysis Probe, Stockholm, Sweden; CMA-12, 20,000 Da limit, membrane length 2 mm, membrane diameter 0.5 mm) was implanted in the right LS or NAc. Microdialysis probes were perfused with aCSF at a 2 μL/min flow rate using an infusion pump (Model 210 RWD, RWD Life Science Co., Ltd., China). After a stabilization period of 90 min, when similar neurotransmitter concentrations were observed between samples, baseline perfusion samples were recollected (the percentage of variability between collected samples accepted is 10%). The protocol used is according to each experiment. At the end of each experiment, animals were sacrificed, and brains were quickly removed and stored in 4% PFA. Brain sections of 50 μm were stained with methylene blue, and the cannula or probe placement was examined microscopically.