Vt1000s vibratome

Mice were decapitated following isoflurane anesthesia the day after the last extinction session. Brains were dissected and coronal slices (300 μm) containing the NAc were cut with a Vibratome (VT1000S, Leica Microsystems) in an ice-cold artificial cerebrospinal fluid solution (ACSF), in which NaCl was replaced by an equiosmolar concentration of sucrose. ACSF consisted of (in mM): 130 NaCl, 3 KCl, 1.25 NaH2PO4, 26 NaHCO₃, 10 glucose, 1 MgCl₂ and 2 CaCl₂ (pH 7.2–7.4 when saturated with 95% O₂/5% CO₂). Slices were incubated in ACSF at 32–34 °C for 45 mi n and kept at 22–25 °C thereafter, until transfer t o the recording chamber. For all electrophysiology experiments, aCSF in the recording chamber was supplemented with 0.075 mM dopamine and 0.05 mM Na-metabisulfite to prevent dopamine oxidation (see Results). Slices were viewed using infrared differential interference contrast optics under an upright microscope (Eclipse FN1, Nikon Instruments Inc.) with a 40x water-immersion objective.

C57Bl/6J mice were decapitated following cervical dislocation. The brain was removed and coronal slices (250 μm) containing the nucleus accumbens, the ventral hippocampus, and the amygdala were cut with a Vibratome (VT1000S, Leica Microsystems) in an ice-cold artificial cerebrospinal fluid solution (ACSF), in which NaCl was replaced by an equiosmolar concentration of sucrose. ACSF consisted of 130 mM NaCl, 3 mM KCl, 1.25 mM NaH2PO4, 26 mM NaHCO3, 10 mM glucose, 1 mM MgCl2, and 2 mM CaCl2 (pH 7.2–7.4 when saturated with 95% O2/5% CO2). Slices were incubated in ACSF at 32–34°C for 25 min and kept at 22–25°C thereafter, until transfer to the recording chamber. The osmolarity of all solutions was 300–315 mOsm. Slices were viewed using infrared 270 differential interference contrast optics under an upright microscope (Slice Scope Pro, 271 Scientifica) with a 40 × water-immersion objective.

Following prefrontal injection of AAV-Cre or GFP, naïve mice were cervically dislocated and decapitated. The brain was removed and coronal slices of prefrontal cortex and nucleus accumbens were cut with a Vibratome (VT1000S, Leica Microsystems) in an ice-cold artificial cerebrospinal fluid solution (ACSF), in which NaCl was replaced by an equiosmolar concentration of sucrose. ACSF consisted of 130 mM NaCl, 3 mM KCl, 1.25 mM NaH2PO4, 26 mM NaHCO3, 10 mM glucose, 1 mM MgCl2, and 2 mM CaCl2 (pH 7.2–7.4 when saturated with 95% O2/5% CO2). Slices were incubated in ACSF at 32–34 °C for 25 min and kept at 22–25 °C thereafter, until transfer to the recording chamber. The osmolarity of all extracellular solutions was 300–315 mOsm. Slices were viewed using infrared differential interference contrast optics under an upright microscope (Slice Scope Pro, Scientifica) with a 40 × water-immersion objective.