Dopamine acts as the final common pathway for all reinforcing substances and behaviors, leading to its release in the brain's reward circuitry.

“but dopamine has become uh kind of the common currency for measuring pleasure reward and motivation it's not the only neurotransmitter involved in that process obviously but it is the final common pathway for all reinforcing substances and behaviors so whether the substance is primarily you know modulating our serotonergic system or norepinephrine or the nicotinic system or the endogenous opioid system or the endogenous canabo system the final common pathway for all of those chemical Cascades is to release dopamine in a dedicated part of the brain called the reward circuitry which consists of the prefrontal cortex that's that large gray matter area right behind our foreheads and then these deeper lyic or emotion brain structures like the nucleus accumbens and the vental tegmental area”