An important observation is that in behavioral studies, rodents would consistently self-administer selective norepinephrine and dopamine releasing agents such as d-amphetamine, yet compounds that also release serotonin like naphthylisopropylamine would not be self-administered.
A notable finding is that in behavioral studies, rodents consistently engage with selective agents that increase norepinephrine and dopamine levels, whereas compounds that also elevate serotonin levels, such as naphthylisopropylamine, are not self-administered.