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