Scientists are confident this new discovery could lead to new ways to make drugs to treat the symptoms of Parkinson’s disease, a movement disorder that is suspected to be caused by the loss of cells that make dopamine.

As was recently revealed by scientists at Oregon Health & Science University, the neurotransmitter adenosine functions as a brake on the action of dopamine, another well-known neurotransmitter involved in motor control.

The discovery, published today in Nature, suggests that adenosine and dopamine have a sort of push-pull dynamic in the brain.

“There are two neuronal circuits: one that helps promote action and the other that inhibits action,” explains senior author Haining Zhong. “Dopamine promotes the first circuit to enable movement, and adenosine is the ‘brake’ that promotes the second circuit and brings balance to the system.”

Dopamine is essential for movement, reward, motivation, and learning, and scientists have long thought that the striatum, a key part of the brain, is influenced by an opposing dynamic of neuronal transmission.

In Parkinson’s disease, the striatum is also the first brain region to lose dopamine-producing cells.

“People for a long time suspected there has to be this push-pull system,” adds co-author Tianyi Mao.

As the new study shows, adenosine is the neurotransmitter that counteracts the effects of dopamine for the first time in a clear and conclusive way.

Genetically modified protein probes created in the Zhong and Mao labs were employed in the research of mice.

Just last month, a paper highlighting this approach was featured in the journal Nature Methods.

Adenosine is notable for being the receptor that caffeine acts upon.

“Coffee acts in our brain through the same receptors,” Mao adds. “Drinking coffee lifts the brake imposed by adenosine.”

Source: 10.1038/s41586-022-05407-4

Image Credit: Getty