Dopamine: The Reward and Reinforcement
Neurotransmitter
Like serotonin, dopamine is considered a “feel-good”
neurotransmitter. It is most famously associated with
motivation and reward, and it gets released when we do
things like have sex, listen to our favorite music, eat, or
watch our favorite sports team succeed. It also spikes when
a new work opportunity or promotion presents itself, when
we spot someone from across the bar that we find attractive,
or when we get a notification of “likes” on social media
posts. When goals are set and met, our dopamine system
lights up, helping to motivate us to do things that evolution
has deemed good for us and the species. But this system,
like many others, can become dysfunctional in the modern
world.
Because of dopamine’s role in motivation, it is heavily
involved in aspects of executive function, where it mediates
motor control, arousal, and reinforcement. Its presence is
reduced in addicts, who attempt to normalize their levels
with substances or actions. This is one of the reasons
“uppers” are so addictive, as they commonly increase levels
of dopamine in the brain, via a variety of mechanisms.
Cocaine, for example, inhibits dopamine reuptake, resulting
in increased dopamine concentrations in the space between
neurons. Methamphetamine, on the other hand, causes a
flood of dopamine from the presynaptic neuron, while also
preventing its reuptake. “Crystal meth,” one form of
methamphetamine, is highly neurotoxic, killing off natural
dopamine-producing cells, which compounds its highly