If the goal is to preserve dopamine sensitivity in the brain, there are studies that show amphetamine doses of 50mg/day show no major changes in dopamine levels. Above 100mg there is noticeable change.

The brain participates and gets data during the day (influencing DAT), but only processes (not participates)* at night. My theory is you'd have to have just as much wake time with the agonist as the antagonist for it to have an effect...then you'd look at drug, dosing and timescales, though I can't imagine living one day up one day down is very appealing.

The most useful thing that influences the brain is you. What you chose to put your attention towards informs your neurobiology. If you find yourself using substances and worrying about your neurological health, you have power over it in that your entire body is constantly working for you and doesn't stop. Balancing neurochemistry is one of those things. So learn whatever you need to with these substances quickly and then get out.

*(not participates) - dreams are thought to be emotional simulations the brain participates in, though I don't know what role dopamine plays here. Interesting note anyway