2-Minute Neuroscience: L-DOPA

L-DOPA is an amino acid involved in the synthesis of the neurotransmitter dopamine, as well as the most common treatment for Parkinson’s disease. In this video, I discuss L-DOPA as a Parkinson’s disease treatment.

TRANSCRIPT:

L-DOPA is an amino acid involved in the synthesis of the neurotransmitter dopamine. When dopamine is produced in the brain, the amino acid tyrosine is first converted to L-DOPA and then L-DOPA is converted to dopamine. While dopamine administered as a drug cannot pass the blood-brain barrier to enter the brain, L-DOPA can, and this characteristic has helped to make L-DOPA the most common treatment for Parkinson’s disease.

Parkinson’s disease is characterized by the death of dopamine neurons in a region of the brainstem called the substantia nigra, and a subsequent deficiency of dopamine in a group of structures known as the basal ganglia. This dopamine deficiency is thought to contribute to the problems Parkinson’s patients experience with movement.

L-DOPA has a remarkable ability to reduce the symptoms of Parkinson’s disease in some patients. The generally accepted mechanism for this action is that the brain is able to use L-DOPA to synthesize more dopamine and replenish its depleted dopamine stores. While this does seem to be a main characteristic of L-DOPA’s mechanism, however, it is thought that L-DOPA may exert a therapeutic effect through other mechanisms as well, such as by acting as a neurotransmitter on its own. While L-DOPA can effectively treat the symptoms of Parkinson’s disease, it is not able to stop the neurodegeneration caused by the disease. Thus, Parkinson’s disease continues to progress even with L-DOPA treatment. Additionally, over time L-DOPA’s effectiveness begins to decrease and eventually movement problems, known as L-DOPA dyskinesias, may occur in response to L-DOPA treatment. L-DOPA dyskinesias typically involve quick involuntary movements, but may also include a number of other complications like uncontrolled muscle contractions or writhing movements. The mechanisms underlying L-DOPA dyskinesias are still not completely understood, and may involve factors like the continued death of dopamine neurons in the substantia nigra and fluctuations in dopamine levels caused by L-DOPA treatment.

REFERENCES:

Halbig TD, Koller WC. 2007. Levodopa. In: Koller WC, Melamed E, eds. Parkinson's disease and related disorders, Part II. Amsterdam: Elsevier.

Obeso JA, Stamelou M, Goetz CG, et al. Past, present, and future of Parkinson's disease: A special essay on the 200th Anniversary of the Shaking Palsy.
Mov Disord. 2017 Sep;32(9):1264-1310. doi: 10.1002/mds.27115.

Special thanks to Nicole Lookfong for help with fact-checking this video.

[Kilo_of_Milk]

Nice, who doesn't love a 2 min educational video

[trinitywalter]

I've heard that the reason why L-dopa use causes dyskinesias is because it inhibits some of the serotonin in the brain, which is also partially responsible for movement disorders. If L-dopa is taken with 5-HTP it can be a bit balanced because 5-HTP inhibits some dopamine

[aamirrazak]

Great video I wish there was some way to prevent the neurodegeneration associated with Parkinson’s like help get the substantia Nigra to make more dopamine... maybe one day it’s sad that even with l dopa symptoms return

[quicknessquantum]

It also increases hgh by a lot which is why ima take it but only while I’m sleep

[sdmdijr]

Please research Dopa-Responsive Dystonia because It is a rare disorder causing dopmine deficiency, and still almost no one knows anything about it. I found out I carry and have this disorder, after passing to my daughter who started displaying significant physical mobility issues, very similar to parkonsonism movements. It is so annoying that pharmacists and others don't know anything about this form or any other of Dystonia therefore don't understand that we CANNOT "overdose" on dopamine and we need more depending on our level of movement and cant really say exactly.

[tempseyy]

I got a question, the blood brain barrier can be penetrated by any drug that has influence in the bloodstream, right? Or there is any other thing im not in knowledge?

[gutubirutesema]

I have 6 years baby with this problem Ethiopia, oromia yekkatit 12 hosp of a.a

[sondostawfiq]

How does it pass the BBB by active Transport (from low to high) when there is low conc of dopamine in the brain already ??

[jasonsmith]

Is L Dopa a good treatment against depression

[pratimachaurasiya]

Due to downside caption I m not able to see the structure properly

[goodfella]

decrease over time is a myth and wrong