Table 1.

Model parameters

Diameter d (μm) Length L (μm) Segments
Geometric
Axon initial segment 1.5 20 10
Axon hillock 1.5-15 5 10
Soma 15 25 1
d0: 3, 2; λT: 200,
Dendrite: proximal 150 200 200
Dendrite: distal λT: 200, 150 200, 450 200, 450
Electronic
Ri: intracellular resistivity (Ω cm) 70
Cm: specific membrane capacitance (μF cm−2) 1.2
Rm: specific membrane resistance (Ω cm2) 30,000
Na (S cm−2) K (S cm−2) Pca (cm sec−1) Ca-Orange (μm) Endogenous buffer (mm)
Mechanism densities
Axon initial segment 1 0.015 0 0 0
Axon hillock 0.026 0.0336 0 0 0
Soma 0.026 0.0336 0 0 0
Dendrite: proximal 0.026 0.0336 1.8 × 10−4 150, 82.5-135 1.4
Dendrite: distal 0.026, 0 0.0336, 0 1.8 × 10−4 150, 82.5-135 1.4
  • Values of parameters used in the model cell for numerical simulation of action potential backpropagation into the apical dendrite. Na and K, Densities of Na+ and K+ conductance; PCa, permeability of high threshold Ca2+ channels. d0, initial dendritic diameter, at soma; λT, exponential decay length of dendritic taper. The length of the distal dendritic section was 200 μm in all modeling, except for the generation of the rise time ratio curves in Fig. 7H, where it was 450 μm. Dendritic diameter and taper was d0 = 3, λT = 200 for a standard dendrite, and d0 = 2, λT = 150 for a thin dendrite.