I'm reading Kandel. Chapter 3 states the following:
Because the initial segment of the axon has the highest density of voltage-sensitive Na+ channels and therefore the lowest threshold for generating an action potential, an input signal spreading passively along the cell membrane is more likely to give rise to an action potential at the initial segment than at other sites in the cell.
I know it is possible to have dendritic spikes, which is an action potential given a much stronger input to open enough Na+ channels. But can there be a different action potential, not axonic nor dendritc, given that enough Na+ channels locally open in the cell membrane?
I've seen some papers talk about "somatic action potential", but its meaning and how it works I don't understand.