The progression of Parkinson’s disease is characterized by a reduced ability of the brain to produce dopamine, a neurotransmitter responsible for the messaging that controls body movement. For this reason, much research in the area concentrates on developing therapies that can arrest this slide, and scientists in Finland have now uncovered a promising path forward in the form of a new molecule found to boost dopamine levels in mice.

Improving the brain’s capability to generate dopamine, and protecting the healthy dopamine-producing brain cells that remain, is a key focus for medical scientists working on new therapies for Parkinson’s. Generally speaking, by the time a patient is diagnosed with the condition they have already lost 70 to 80 precent of these cells, and there are currently no available treatments that can halt this degenerative process.

One possibility, however, is through a growth-factor protein called glial cell line-derived neurotrophic factor (GDNF). Previous research has shown that administering this protein could offer a way of treating or even reversing the effects of Parkinson’s, including one 2019 study that tested out a brain implant in human patients as delivery system, with promising results.

A shortcoming of this approach, however, is the relatively large size of the GDNF protein. This means it requires complex procedures (like the one mentioned above), to get it into the brain, but the team at the University of Helsinki claim to have uncovered a molecule that appears to be a lot more manageable. Called BT13, the molecule targets the same receptors as GDNF, but is far smaller in size.

Its effectiveness in treating Parkinson’s was put to the test in rodent studies, where mice with the disease were administered the molecule. The scientists found that it not only led to an increase in dopamine levels, but also activated a receptor that protected healthy brain cells that produce dopamine.

“People with Parkinson’s desperately need a new treatment that can stop the condition in its tracks, instead of just masking the symptoms,” says Professor David Dexter, Deputy Director of Research at Parkinson’s UK. “One of the biggest challenges for Parkinson’s research is how to get drugs past the blood-brain barrier, so the exciting discovery of BT13 has opened up a new avenue for research to explore.”

The team is now working to improve the Parkinson’s-fighting properties of BT13, as well as investigating other compounds like it with a view to conducting tests on human subjects.

“We are constantly working on improving the effectiveness of BT13 and we are now testing a series of similar BT13 compounds,” Dr Yulia Sidorova, lead researcher on the study. “Our ultimate goal is to progress these compounds to clinical trials.”