Hello,
well, basically, I am looking of an answer to this question:
http://www.longecity...nism-of-action/
That is, nootropics utilise various mechanisms of action. I haven't found a comprehensive list. The onyl one I know is rising acetylcholine levels (by either supplying precursors, or blocking destruction of it).
What are the other mechanisms? Answering this question can help us build more effective stacks.