Would one simply keep there finger down on the endorphins, dopamine and oxytocin buttons until they die of an overdose of bliss. — Benj96

We already have plenty of real world experience. We don't need a magic conveyor belt. Any run of the mill pharmaceutical will do. Your local chain drugstore and your local drug dealer both have plenty of options. On the legal side are the SSRIs (selective seratonin reuptake inhibitors) and on the illegal side are cocaine. In fact in terms of neurochemistry, a Prozac or other SSRI is nothing more than a cleaner version of cocaine, simply being more specific in which neurotransmitters it affects. It's merely a matter of degree. Prescription opiates are another example of a legal and highly habituating drug that some people indulge in to their doom.

This brings up another issue. Regulating subjective mental/emotional states (and even behavior, in the case of the heavier-duty psych and recreational drugs) isn't only about delivering neurotransmitters to various areas of the brain. The idea of reuptake is fascinating. What cocaine (and Prozac, Zoloft, etc.) do is sneak into the synapses between two neurons and simply prevent the neurotransmitters from being reabsorbed into their respective neurons. Instead, they flood the synaptic junction. In other words the effect is second order: there's not more of the neurotransmitter; there's an inhibition of the mechanism that reabsorbs it from the synapse. So the same given amount of neurotransmitter stays in the synapse longer hence produces an enhanced effect.

Don't know if any of this was helpful but it's everything I know about neurotransmitters.

The direct answer to your question is that rats love to press the cocaine lever and will do so to their death. Some humans too.

Thank you. Very interesting info. I'm going to look up this rat experiment