In order for the axon to initiate an action potential, we know that the axon initial segment must be brought to threshold. So my question is as follows:
Say we have the minimum charge input, "X", necessary to depolarize the axon initial segment of Neuron 1.
Now, we have Neuron 2, which has a larger soma. Will this same input X be sufficient to depolarize the axon initial segment of Neuron 2?
I am trying to explore how physical concepts like capacitance manifest in biological systems. Neuron 1's soma (approximated as a sphere) presumably has a lower capacitance than Neuron 2's soma (approximated as a sphere), due to the difference in cross sectional area of the somas. Therefore, I would assume that Neuron 2's axon initial segment requires greater input to depolarize than Neuron 1's axon initial segment.
Is this simplistic idealization of somas actually observed in experiments?