If depolarizing membrane potentials open voltage-gated sodium channels, what closes them?
Actually, EPSP's push the membrane potential to threshold, which initiates an action potential.
The action potential is "created" when the positively-charged
Then, they nearly instantaneously inactivate via an inactivation gate closing the channel intracellularly.
Contemporaneously, voltage-gated potassium channels (mainly the delayed rectifiers) open as a result of
I like cellular-molecular neuroscience. :)