Figure 4. Neuronal geometry shapes dendrites to nucleus signalling.

(a–c) Effects of the diameter of the dendrite. All neurons have a small soma. (d–f) Effects of branching. All neurons have a small soma and a thin dendrite (tertiary dendritic diameter). (g–i) Effects of the soma size combined with the other factors. (a,d,g) Geometry variations with their symbol. (b,e,h) Plots of the areas under the curve of the time courses of nuclear pT34-DARPP-32 concentration (as in Fig. 3e) following the release of cAMP at nine dendritic locations, as a function of the distance to the soma. (c,f,i) Same plot as in b,e,h normalized to the dendrite indicated in ordinates title. All soma and nuclei are ellipsoids. Semi-principal axes: small soma, 5.5, 5 and 5 μm; big soma: 10, 5 and 5 μm; nucleus: 4.5, 4 and 4 μm. All dendrites and branches are modelled as cylinders. Diameter of the primary dendrite (solid line): 2.25 μm; secondary dendrite (dashed line): 1.75 μm; tertiary dendrite (dotted line): 1.25 μm. Length of the dendrite at the primary location: 25 μm; secondary location: 50 μm; tertiary location: 60 μm; secondary branch location: 40 μm; tertiary branch location: 50 μm.