We recorded neurons in the medial subdivision of the CeA with sharp micropipettes filled with 3M KCl (impedance range of 60–90 MΩ) using current-clamp mode. We held most neurons near their resting membrane potential (RMP), and the RMP observed in control conditions was maintained throughout the experiment. Data were acquired with an Axoclamp-2 preamplifier (Axon Instruments, Foster City, CA) and stored for later analysis using pClamp software (Axon Instruments). Pharmacologically-isolated GABA receptor-mediated inhibitory postsynaptic currents (IPSPs) were evoked by stimulating locally within the CeA through a bipolar stimulating electrode while superfusing the slices with the glutamate receptor blockers 6-cyano-7-nitroquinoxaline-2,3-dione (DNQX, 20 μM) and DL-2-amino-5-phosphonovalerate (APV, 30 μM). We also applied the GABAB receptor antagonist CGP 55845 (1 μM) to isolate the GABAA receptor-mediated component of the IPSP.
