Figure 11.

Stochastic calcium bursts in a dendrite model show large spatiotemporal variation of membrane potentials. This figure shows voltage during five different runs of the stochastic well-mixed model of a PC dendrite (A–E). A, B, In the first two runs, the burst consisted of 2 calcium spikes; in the other runs, only 1 calcium spike was generated. A, First 8 ms of the voltage traces recorded from all compartments of the dendritic tree are overlaid. Inset, Complete burst. Gray vertical lines indicate the time points for which the spatial maps are shown. B, Spatial maps of membrane potential throughout the dendrite for each time point marked with gray lines in A. Each time point has its own linear color scale to emphasize differences within single maps. C, Voltage range for all compartments (difference of maximum V and minimum V at each time point across 50 trials). Gray represents compartments with diameter ≥0.7 μm; red represents smaller-diameter ones; black represents mean. D, Spatial correlation of voltage of first 5 time points across 50 trials. Different shades of gray are used in sidebars to highlight subtrees as shown in E. Dendrites with diameter <0.7 μm are marked with red dots. E, Dendritic tree plotted in different shades of gray to highlight two subtrees stemming out of the primary dendritic branch plotted in black. Red circles represent dendrites with diameter <0.7 μm.