Which statement best describes the normal dopamine-driven process of neural communication at a synapse and how cocaine interferes with it?

• A. Normal: presynaptic release activates postsynaptic receptors; dopamine cleared by transporter; cocaine blocks transporter, prolonging dopamine.
• B. Normal: dopamine cleared mainly by extracellular enzymes; cocaine increases vesicle release, not reuptake.
• C. Normal: dopamine is taken up by postsynaptic cells; cocaine acts as a direct postsynaptic dopamine agonist.
• D. Normal: dopamine is rapidly metabolized in the cleft; cocaine inhibits those enzymes, causing accumulation.

Answer: (A)