2.5.1. mEPSC recording

Recording pipettes filled with an internal solution containing (in mM): 135 cesium methanesulfonate, 10 HEPES, 0.2 EGTA, 5 QX314, 5 NaCl, 2 MgATP, 0.3 NaGTP, 5 phosphocreatine; pH 7.3; ~295 mOsm were used to patch onto BLA principal neurons. The cells were held at −70 mV (V_Hold) and miniature excitatory post-synaptic currents (mEPSCs) were isolated using gabazine (10 μm, HelloBio, UK) and tetrodotoxin (TTX, 1 μm, HelloBio, UK) in the perfusate. Once the whole-cell configuration had been achieved, the cells were allowed to stabilize for 5 min followed by data acquisition. A total of 5 min of mEPSC recordings were analyzed for each cell. Mini Analysis Program (Synaptosoft Inc., USA) was used for the analysis and the threshold amplitude for each event was set at 5 pA. All cells included in the frequency and amplitude bar graph plots were included in the inter-event interval (IEI) cumulative plots. The frequency graph plotted at the cell level while the IEI plots were constructed using individual IEI values from the entire 5 min recording from all cells.