Neuron function question

[David Todtman]

Kal,
It is very helpful to have your response.

I think you are correct about my need to get a more explicit text.

Can you note for me how a receptor is caused to be up-regulated or
down-regulated?  I would think that molecule/receptor binding is a 'digital'
function.  I.e., if the ligand molecule encounters a fitting receptor it
either binds or does not.  One cannot have a partial bind or a 'bigger
bind.'  Eh?  Does the internal portion of the receptor, in up-regulation,
release more of its chemical?

Also, back to the question of ionotropic vs metabotropic functions, is
dopamine an example of a ligand that causes (mostly) metabotropic change?

Again, the responses to my questions are very helpful to me.  (This is
interesting stuff.)

Ciao,
David