2-Minute Neuroscience: L-DOPA

2-Minute Neuroscience: L-DOPA

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.

4 thoughts on “2-Minute Neuroscience: L-DOPA

  1. 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

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