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[♪INTRO]
Your brain has a limited number of molecules that let you do everything you do.
And in pop culture, we tend to have a pretty narrow view
of what each molecule regulates.
Dopamine makes you happy, right?
Well, it totally can. But this neurotransmitter can also help you move around,
take appropriate risks, and focus! And that is just the tip of the iceberg.
So when you have different amounts of dopamine in certain regions of your brain,
it often affects you in more ways than one.
Dopamine is made in and sent to a few different parts of the brain.
It often gets sent to the caudate putamen,
which is a part of the brain involved in producing movement.
So dopamine is an influential chemical in diseases that affect movement,
like Parkinson's Disease.
Parkinson’s is a neurodegenerative disease that makes it difficult to initiate
and control movement like walking or writing.
So, many people diagnosed with Parkinson’s experience
a characteristic shaking symptom.
And while dopamine is not the only chemical involved,
there isn’t as much of it in the brains of people diagnosed with Parkinson’s.
This is likely because the brain cells that release it
progressively degenerate as the disease worsens.
About half a million people in the US alone
are diagnosed with this kind of disorder. And today, there is no cure.
But there are some treatments that some people find helpful,
like the drug pramipexole.
It is a drug that is designed to look like dopamine and bind to dopamine receptors.
Basically, it pretends to be dopamine.
This reduces the symptoms of movement disorders like Parkinson’s disease
and Restless Leg Syndrome.
But dopamine doesn’t just go to the caudate putamen.
It also goes to the nucleus accumbens,
which can impact depression symptoms, among many other things.
A 2010 study published in Biological Psychiatry found that some people
with treatment-resistant depression had symptom improvement
after deep brain stimulation to the nucleus accumbens.
Depression is also a commonly reported symptom of Parkinson’s.
So these symptoms likely go hand in hand
because they can both be the result of low dopamine in the same person.
And it can be a good thing that dopamine acts in both of these ways
when we’re trying to treat multiple symptoms,
because it means that pramipexole could be a two-in-one treatment
for motor symptoms and depression in Parkinson’s.
Even if you don’t have Parkinson’s, it can treat depression alone.
Stimulating dopamine in your brain affects a wide range of feelings and behaviors.
But that wide range also means this treatment could take things in another direction.
Increasing your dopamine levels in the nucleus accumbens
can send your risk-taking tendencies into overdrive.
For example, Parkinson’s medications have been known to lead to
side effects like being more prone to compulsive gambling.
Motor control and risk-taking are very different behaviors,
but both are controlled by dopamine.
So medications that regulate dopamine levels could bring your motor control back
to manageable levels but over-activate your drive for seeking rewards.
Manipulating dopamine with drugs like pramipexole can lead to
lots of other off-target, or unintended effects
because dopamine can be found pretty much everywhere in the brain.
Dopamine also goes to the prefrontal cortex to impact attention,
the hippocampus to impact memory,
and the hypothalamus to impact hormone secretion, and the list goes on.
Some pharmaceuticals even create Parkinson's-like symptoms
in people who previously did not have movement disorders.
And unfortunately, we can’t deliver a drug to just the part of the brain
where the dopamine regulates movement.
The drug is systemically administered.
So it goes to all parts of the brain and acts wherever there are dopamine receptors.
Whether these impacts are relatively good or bad
often depends on the person and their pre-existing brain chemistry.
So one neurotransmitter does not exclusively make you just happy, mobile, or focused.
The same one often does all of these things in complex and interconnected ways!
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[♪OUTRO]