Figure 1

Intensive activity at hippocampal GABAergic neurons induces spontaneous spikes, i.e., activity-induced spontaneous spikes (AISS), under current-clamp and voltage-clamp. A sequential depolarization pulses (150 pA or 200 pA/3 seconds with 7 seconds of intervals) were injected into the neurons to evoke the spikes. A) shows spikes induced by depolarization currents (150 pA; blue trace) and AISS (red trace) under current-clamp recording. Calibration bars are 10 mV and 10 seconds. B) shows spikes induced by depolarization voltages (15 mV; blue trace) and AISS (red trace) under voltage-clamp. Calibration bars are 200 pA and 10 seconds. C) illustrates the expanded waveforms of evoked spikes (blue trace), evoked spikes just before AISS (green trace) and AISS (red trace) from panel A. D) shows the expanded waveforms of evoked spikes (blue trace), evoked spikes just before AISS (green trace) and AISS (red trace) from panel B. E) shows the dynamical change in threshold potential (Vts) during AISS induction. F) shows the dynamical change in the coefficient variation (CV) of Vts during AISS induction. G) shows the dynamical change in energetic barrier (ΔV) during AISS induction. H) shows the dynamical change in the CV of ΔV during AISS induction (n = 23).