Mice were killed by rapid cervical dislocation and decapitated and a 3-mm coronal block containing the amygdala was cut using a coronal brain matrix kept on ice. Coronal slices (300 μm) were made on a Leica VT1000S vibratome (Leica Microsystems, Bannockburn, IL, USA) in a 1−4 °C, oxygenated (95% O2, 5% CO2), low Na+ artificial cerebral spinal fluid (ACSF) containing (in mm): 194 sucrose, 20 NaCl, 2.5 KCl, 2 CaCl2, 1 MgSO4, 1.2 NaH2PO4, 10 glucose and 26 NaHCO3. Once cut, sections were transferred to a holding chamber containing oxygenated ACSF (in mm): 124 NaCl, 2.5 KCl, 2 CaCl2, 1.2 MgSO4, 1 NaH2PO4, 10 glucose and 26 NaHCO3 at 24 °C. After 1–4 h, sections were placed in the recording chamber superfused with oxygenated ACSF at a flow rate of 2 ml/min. To isolate pharmacologically IPSCs, ACSF was supplemented with a combination of 20 μm CNQX and 50 μm d/l AP-5. For field recordings, ACSF was supplemented with 25 μm picrotoxin. All experiments were carried out at 23–25 °C. ACSF was supplemented with 0.5 g/l fatty acid free bovine serum albumin. Slices were incubated in AM3506 (2 μm) or vehicle for at least 20–30 min before the start of recording.
