Parkinson’s breakthrough changes what we know about dopamine

[Mij]

Dopamine isn't the brain's throttle- it's the oil that keeps movement running, and the insight could change Parkinson's care

Date: December 22, 2025

Source: McGill University

Summary: A new study shows dopamine isn’t the brain’s movement “gas pedal” after all. Instead of setting speed or strength, it quietly enables movement in the background, much like oil in an engine. When scientists manipulated dopamine during movement, nothing changed—but restoring baseline dopamine levels made a big difference. The finding could reshape how Parkinson’s disease is treated.

Dopamine Acts as Support, Not a Speed Controller

The study suggests dopamine does not act as a moment-by-moment controller of movement. Instead, it serves a more fundamental role.

"Rather than acting as a throttle that sets movement speed, dopamine appears to function more like engine oil. It's essential for the system to run, but not the signal that determines how fast each action is executed," said Tritsch.

 

[hotblack]

Details on the paper behind this:

Subsecond dopamine fluctuations do not specify the vigor of ongoing actions

Spoiler: Authors

Liu, Haixin; Melani, Riccardo; Maltese, Marta; Taniguchi, James; Sankaramanchi, Akhila; Zeng, Ruoheng; Martin, Jenna R.; Tritsch, Nicolas X.

Abstract
Abstract Dopamine (DA) is essential for the production of vigorous actions, but how DA modifies the gain of motor commands remains unclear. Here we show that subsecond DA transients in the striatum of mice are neither required nor sufficient for specifying the vigor of ongoing forelimb movements. Our findings have important implications for our understanding of how DA contributes to motor control under physiological conditions and in Parkinson’s disease.

Web | DOI | PMC | PDF | Nature Neuroscience

 

[Jonathan Edwards]

I think we were taught this as students 50 years ago. Extrapyramidal problems like Parkinson's are due to high level regulatory errors, not lack of immediate drive.

 

[bobbler]

I think we were taught this as students 50 years ago. Extrapyramidal problems like Parkinson's are due to high level regulatory errors, not lack of immediate drive.

I was thinking that I didn’t think anyone ever thought it was the ‘throttle’ but I haven’t read the literature on it to be sure

I’m not convinced on the grease analogy off the top of my head either particularly although whilst I like a good analogy where it’s used to explain nuance or specificity of a situation I’ve noticed that medicine tends to be really poor at using and therefore picking analogies (despite being fond of them) vs eg how this is used for business.

So it tends to focus on something it (normally someone in a certain demographics assumptions of what it think the plebia understand - which is often insightful in how it’s off) thinks is a part ‘people will know of’ and that’ll have to do as the closest we will all get rather than picking the thing that’s closest in mechanism/specifucs of mechanism that needs to be got across.

So I’m aware their analogies sort of don’t necessarily mean the same thing as I assume they do from the way they are used elsewhere


However just the fact that dopamine makes one feel good but in a certain way after a session of exercise but not hyper or shaky like adrenaline does said it wasn’t about tank fuel or throttle. I’d guess it’s that problem of people who like to generalize quite specific situation—> consequences things to ‘someone else’s mood’ in quite a sledgehammer way that hasn’t helped there. I’ve always been cynical of the generic ‘X makes people feel y’ level stuff on hormones when I got the sense the y they described was simplistic vs what those inside those bodies could actually describe.

And its implication supposedly in things like restless legs most people know (adhd is another isn’t it?) seems a bit more like properception or something more coordination (and therefore anticipation) related system was impacted by it (or vice versa)