New research conducted at the Université de Montréal suggests that Parkinson’s disease may silently progress for over a decade before symptoms appear. The study, which was published in the journal Nature Communications, found that movement circuits in the brain can maintain function even with a drastic reduction of active dopamine secretion, which is contrary to popular belief.
Dopamine is considered crucial for movement, and its decrease is a hallmark of Parkinson’s disease. However, the research conducted at the Université de Montréal found that the brain’s movement circuits were surprisingly resilient, functioning normally even with a nearly complete loss of active dopamine secretion.
“This observation went against our initial hypothesis, but that’s often the way it is in science, and it forced us to re-evaluate our certainties about what dopamine really does in the brain,” said Louis-Éric Trudeau, a neuroscientist and professor at the Université de Montréal.
The researchers used genetic manipulations to eliminate the ability of dopamine-producing neurons to release the chemical messenger. Surprisingly, mice in the study showed a completely normal capacity for movement, despite the loss of dopamine secretion. Measurements of dopamine levels in the brain also revealed that extracellular levels of dopamine in the mice were normal.
These findings suggest that the activity of movement circuits in the brain requires only low basal levels of dopamine. Therefore, in the early stages of Parkinson’s disease, basal dopamine levels in the brain may remain sufficiently high for many years, despite the gradual loss of dopamine-producing neurons. It is only when a minimum threshold is exceeded that motor perturbations appear.
The researchers believe that by understanding the mechanisms involved in dopamine secretion in the brain, new therapeutic approaches to alleviate symptoms of Parkinson’s disease could be developed. Currently, Parkinson’s disease is an incurable neurodegenerative disease that affects millions of people worldwide.
The findings of this study could pave the way for new methods for treating symptoms of Parkinson’s disease. However, further research is needed to fully understand the mechanisms behind dopamine secretion in the brain and how they can be targeted with therapeutic approaches.
If you or someone close to you has recently been diagnosed with Parkinson’s disease, this research highlights the importance of early detection and intervention. While the disease may progress silently for over a decade, understanding the underlying mechanisms can lead to improved treatment options and a better quality of life for those affected by Parkinson’s.