Figure 1

Chronic blockade of neuronal activity induces a homeostatic increase in intrinsic excitability. (A,B) Whole-cell patch clamp recording of rat dissociated hippocampal neurons cultured in a high density (DIV 12–14) that were treated for 48 h with vehicle control (CTL-H₂O, 0.1% H₂O), TTX (0.5-1 μM), or BC (20 μM). Following treatment removal, spike trains were evoked in pyramidal neurons by delivering constant somatic current pulses for 500 ms duration at a resting potential of −60 mV. (A) Representative spike trains. (B) Average AP firing rates (Hz) measured in pyramidal neurons treated for 48 h with CTL-H₂O (n = 13), TTX (n = 10), or BC (n = 9). TTX but not BC treatment for 48 h significantly increased AP firing frequency compared to CTL-H₂O treatment. Mean ± SEM (*p < 0.05, **p < 0.01).