Here we address the following questions:
1) Where are action potentials initiated in
cortical pyramidal cells? (Answer: axon initial segment!)
2) How does intitiation of spikes in the axon
influence the variability and reliability of spike intiation in these
3) How does initiation of spikes in the axon
influence the appearance of spikes in the cell body and dendrite?
4) 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.
Movie Explaining This Seminar:
(its 32 megabytes, so please be patient)