Thanks for your comments and questions.
Firstly, on the subject of open-access publishing. We do encourage our researchers to publish their findings in scientific journals that are freely available and we also offer financial help for them to do this - see our open access publishing policy here:http://www.parkinsons.org.uk/research/for_researchers/communicating_your_research.aspx#share_your_findings
But we still have some work to do in making sure our researchers make use of the support we offer - so it's a work in progress.
Secondly, a bit more detail about the study itself. The researchers studied the brains of rats to investigate the nerve cells in a brain area called the globus pallidus external (or GPe).
Many different parts of the brain are involved in coordinating movement (as your diagram shows). We still don't fully understand how all the different parts talk to each other to produce movement but the GPe is thought to play a vital role, acting as a 'coordinating hub'. And it's sometimes described as a 'pacemaker' or regulator of the movement control system within the brain.
What's new about this research study is that they've discovered that there are two different types of cell in the GPe, which together play a vital role in keeping the 'pacemaker' working properly.
In Parkinson’s, it seems these cells stop working properly (or go rogue!). And this may unbalance the whole movement control system, resulting in the disrupted brain rhythms that cause the symptoms of the condition.
The researchers haven't yet worked out exactly how all this happens - or how things like misfolded synuclein may be involved - so the picture is far from complete. But this discovery will hopefully trigger lots of new research to understand all these things.
I hope this helps to answer your questions!!
Senior Research Communications Officer