Here we address the following questions:
- Where are action potentials initiated in cortical pyramidal cells? (Answer: axon initial segment!)
- How does intitiation of spikes in the axon influence the variability and reliability of spike intiation in these cells?
- How does initiation of spikes in the axon influence the appearance of spikes in the cell body and dendrite?
- What are the functional consequences of axonal initiation of action potentials?
Why address these questions? Recently, Nature published a paper, News and Views and editorial that questioned whether or not the fundamental properties established by Hodgkin and Huxley in 1952 for action potential generation apply completely to cortical neurons, because of so-called "unique" properties of spike generation in these cells. In this seminar, we show that cortical neurons behave as predicted by Hodgkin and Huxley theory, thus vindicating this classic theory.