The mechanisms differentiating BPRs among dendritic sectors. In these simulations on a Z+ PC model, type II BPRs were elicited by 500 Hz—10 spikes pf bursts in dendritic sectors I and II and SC synapses were activated by 130 Hz—three spikes trains in the corresponding pf sectors (see Figure 6A). (A) Local generation of minimal EPSPs in one of the terminal compartments of dendritic sectors I (~140 μm from soma) and II (~270 μm from soma). Note the larger and faster EPSP in sector II than I. In the same dendritic compartments, Zin is about twice as large in sector II than I at 10, 100 and 500 Hz. Correspondingly, attenuation follows different profiles in sector I and II. (B) Local currents in one of the terminal compartments of sectors I and II. Note that, in sector 2, the EPSPs trigger a local Ca spike along with a strong activation of Ca currents (Cav3.1, Cav3.2, Cav3.3, Cav2.1) and KCa currents (KCa1.1, KCa 2.2, KCa3.1) and a large [Ca2+]i increase. In sector I, the depolarization is too weak to activate the Ca spike so that ionic currents and [Ca2+]i changes are correspondingly much smaller.