You should read the BL ADD Neuropharmacology e-text for a good start.
People would be more likely to want to help you if you took the time to write a request like the above in a more careful way that doesn't look rushed or sloppy, because they will take you more seriously.

(just a tip for a possible next time)
Here are some search terms you may wish to research on Wikipedia or other information source:
agonist, antagonist, ligand, receptor, reuptake transporter, SAR, VMAT, neuron, G-protein, dopamine, norepinephrine, serotonin, NMDA, GABA, BBB.
Those in combination with the Neuropharmcol. text will give you some background once you've read about all of them.