Dopamine and Parkinson’s Disease

If you or someone you know has been diagnosed with Parkinson’s disease (PD), you may have heard of dopamine. You may have some questions about dopamine and how it affects PD. We are going to look at some of the important points about dopamine in the brain.

What is it?

Dopamine is a chemical produced in the body that is known as a neurotransmitter.¹ Neurotransmitters help the brain send messages from the nerve cells to other cells, including cells in the muscles and heart. These messages can also be between the nerve cells within the brain called neurons.

What does it do?

Dopamine has many functions in the body. It is an important part of motor function, which is how the body moves correctly. It is also an important part of how the brain understands reward and reinforcement.²

It works to make you feel good when you do something correctly. Finally, it is one of the chemicals in the brain that is responsible for sexual arousal.³

Where is it made in the brain?

Dopamine is produced in the substantia nigra, ventral tegmental area, and hypothalamus.¹ You may not remember these complicated names. That is fine! It is probably more important to know what these areas of the brain do:^1,4-6

• The substantia nigra is part of the brain known as the basal ganglia. This part of the brain is responsible for making movement possible.
• The ventral tegmental area is the part of the brain that is responsible for reward and reinforcement.
• The hypothalamus has many functions. It is responsible for sleep, appetite, body temperature, and sexual arousal, among other things. The hypothalamus helps control the autonomic nervous system.

How does PD affect dopamine?

Doctors believe that PD affects the brain’s ability to create dopamine.⁷ Since the brain cannot produce the dopamine it needs, a person’s movement begins to be affected. PD can also cause other symptoms as the brain begins to create less dopamine.⁸

People with PD can have issues with sleep, depression, and blood pressure. Younger people with PD can also have issues with impulse control.⁹ As you can see, these are all related to the parts of the brain that create dopamine. Doctors are not sure why this happens, or what causes PD.

PD causes the neuron cells in the substantia nigra to break down and die. People with PD have 80 percent fewer dopamine-producing cells in their substantia nigra than people without PD have.⁷

Doctors are not sure why this happens. If doctors can figure out why PD causes the brain to stop producing dopamine, they think they may be able to find a better treatment for PD.

How does treatment work?

Currently most of the drugs that treat PD work to either replace or mimic dopamine in a person’s brain.⁷ A few drugs work by keeping the body from breaking down dopamine, so it can stay in a person’s system longer.

Doctors also think that there are other neurotransmitters that affect and are affected by PD.¹⁰ They are currently doing research to find out what these neurotransmitters are and how drugs affecting them may help with better PD treatment in the future. Hopefully, these studies will lead to better outcomes for all people with PD.