Burst/Pause responses (BPR) in the PC model (A) Distribution of the excitatory and inhibitory synapses used for the simulation. The synapses were distributed randomly in the specific dendritic branches. (B) Type I, II, III responses in the Z+ and Z− PC models. Type I responses were elicited by a 500 Hz—10 spikes burst in 100 pfs. This elicited a ~250 Hz burst, that was followed by a pause in Z+ but not in Z− PC models. Type II responses were elicited by a 500 Hz—10 spikes burst in 100 pfs followed by a 130 Hz—three spikes burst in 25 SCs. This elicited a ~250 Hz burst, that was followed by a pause in Z+ but not in Z− PC models. The pause occurred in the Z− model only when the number of SC synapses was increased to 100. Type III responses were elicited by a 130 Hz—three spikes burst in either 25 SCs. This elicited a pause in Z+ but not in Z− PC models. The pause occurred in the Z− model only when the number of SC synapses was increased from 25 to 100. The Z− behaved similarly to Z+ model when the Z− was equalized to Z+ basal firing rate with somatic injection of a constant negative current. (C) Left, Sensitivity of the burst to the number of inhibitory synapses. The interspike interval (ISI) for each spike is reported. Increasing the number of inhibitory synapses does not change the burst but generates progressively longer pauses with a sharper burst/pause transition. Right, using the example with 25 SC synapses for comparison, the impact of ascending axons (aa) stimulation is evaluated. When aa are made identical to pf synapses, there is no clear pause generation. However, this occurs when the aa synapses are potentiated by increasing their postsynaptic maximum conductance and presynaptic release probability (Sims and Hartell, 2005, 2006) demonstrating “functional equivalence” with pf synapses (Walter et al., 2009) in BPR.