IκBαM/M KI neurons exhibit increased spontaneous burst firing and hyperexcitability in culture. A) Example traces of spontaneous action potential (AP) firing from WT and KI hippocampal neurons recorded under whole cell patch in current clamp mode. Scale bar = 20 mV/10 sec (top), 20 mV/1 sec (bottom). B) Quantification of the frequency of spontaneous AP firing and frequency of burst firing normalized to WT levels. N = 28-32 traces, ** = p < 0.01, *** = p < 0.001. C) Example traces of evoked AP firing from WT and KI hippocampal neurons following a series of current injections. Scale bar = 20 mV/50 msec. D) Quantification of number of AP fired during indicated magnitude of current injection. N = 20-21 neurons, *** = p < 0.001.