mM Na2-phosphocreatine, 4 mM Mg-ATP, and 0.3 mM Na2-GTP adjusted to pH 7.35 and osmolality of 285–290 mMol/Kg. Recordings were obtained with a Multiclamp 700B amplifier and Digidata 1550 digitizer using pClamp10 data acquisition software (Molecular Devices). Action potential firing behavior was examined in current clamp mode by injecting a series of 1 sec step current waveforms (from hyperpolarizing to depolarizing) in 5 pA increments until the full dynamic range of the neuron was probed. To standardize measurements for these experiments, a hyperpolarizing bias current was applied as needed to adjust baseline membrane potential to approximately −65 mV. Spontaneous synaptic events were recorded in voltage clamp mode with the holding potential set to −50 mV to facilitate distinction of excitatory (inward) versus inhibitory (outward) events. The GABA-A receptor antagonist picrotoxin was bath applied at 50 uM in the aCSF to block sIPSCs.
