Paired intracellular somatic and dendritic recordings in slice have demonstrated that somatic action potentials do not propagate far into the dendrite. Thus recordings of the main dendrites of Purkinje cells often reveal somatic action potentials as only small wavelets. When the membrane potentials in the soma and large proximal dendrites were compared in the model, a similar result was observed (Figs. 3, 4, and 7). Further, using the model it was possible to demonstrate that the action potential did not propagate into spiny dendrites (a location that electrophysiologists cannot record from), even those relatively close to the soma (Figs. 3, 4, and 10A). Paired intracellular somatic and dendritic recordings have also suggested that the Ca2+ spiking, responsible for the depolarizing spike bursts observed in the soma during higher-amplitude current injections, has a dendritic origin. As shown in Figs. 3B and C, and 4C and D, this was also the case in the model.