Representative whole-cell voltage-clamp recording of spontaneous activity of a neocortical pyramidal cell. A) Current recording of spontaneous IPSCs from a single cell with asterisks indicating a representative slow and fast isolated IPSC and the slow IPSC highlighted in gray. B) Overlay view of the isolated IPSCs indicated by asterisks in A. The horizontal dashed line represents the baseline current. C) Representative large amplitude spontaneous currents, showing both slow and fast events with matched amplitudes from the same cell. Dashed horizontal line represents the baseline current. The dashed line along the decaying slope represents empirical fits to the data. D) IPSC isolated events were quantified by estimating the peak amplitude from baseline, as well as the rise time and decay time constant (τ1). Rise times were estimated as the time between 10 and 90% of the peak amplitude (t1 and t2 respectively). Decay time constants were estimated from empirical fits with a double exponential equation. The exponential time constants (τ1 and τ2) were used as estimates of the decay time (τ2 > τ1).