The location of the axon initial segment affects the bandwidth of spike initiation dynamics
Fig 3
Performance of a rat cortical pyramidal neuron model. We repeated the analysis of Fig 2 for a model of rat neocortical layer 5 pyramidal cells. As in the “ball-and-stick” model, when the AIS moved away from the soma (A), the somatic AP became steeper (A), while its threshold potential decreased (B,C) and its rapidity at onset increased (B,D). The magnitude of the dynamical transfer gain of the model was plotted in the Fourier domain, across increasing soma-AIS distances, normalized to its value at 1 cycle/s (E). The “cut-off” frequency was then studied against the soma-AIS distance (D) and fitted by a logistic function. Color coding as in Fig 2 and error bars (C-F) representing the standard deviation over 100 independent repeated simulations.