These model responses were robust to changes in the densities of all of the ionic channels. For most of the channels, modifying their densities by factors of ≥2 resulted only in left or right shifts of the frequency-current curve. However, changes of >20 % to the amount of P-type Ca2+ channels or of one of the Ca2+-activated K+ channels in the model either suppressed dendritic spikes or caused the model to always fire Ca2+ spikes. Modeling results were also robust to variations in Purkinje cell morphology. We simulated models of two other anatomically reconstructed Purkinje cells with the same channel distributions and got similar responses to current injections.