> What I should have said is that the action of the ionotropic channels
> (or, indeed, of metabotropic receptors on ion channels) can lead to
> the entry of enough positive charge to lead to an action potential.
> The AP, when it reaches the terminal, can precipitate a series of
> events which lead to the release of transmitter.
BINGO! Your two latest replies answered the single main question I had.
Thank you very much for this exchange. All of it was important and enabled
me to understand how to ask the final questions.
Thank you again. This was very enjoyable, interesting, and will be useful.
With all good wishes,