New international research suggests that too much calcium inside brain cells may trigger a chain reaction that leads to Parkinson's.
The findings, reported in the journal Nature Communications, represent another step towards understanding how and why people develop Parkinson's.
Please note that the calcium we're talking about in this study is inside brain cells and does not suggest that people should reduce calcium in their diets.
How calcium and alpha-synuclein interact
Calcium levels rise inside brain cells when they need to release neurotransmitters - such as releasing dopamine to send messages to co-ordinate movement.
This study suggests that when calcium levels increase, alpha-synuclein is activated and attaches to packages of neurotransmitters (called 'synaptic vesicles') which helps them to be released.
For everything to work properly there needs to be the right balance of calcium and alpha-synuclein in the cell.
According to this study, when this balance is disturbed and there is too much of one or the other, alpha-synuclein starts to form toxic clumps that damage the cell.
Towards better treatments
Claire Bale, Head of Research Communications and Engagement at Parkinson's UK, comments:
"We've known for some time that too much calcium or too much alpha-synuclein - the main protein involved in Parkinson's - causes problems for brain cells affected in the condition.
"This particular study is interesting because it's the first time research has shown there may be important interplay between alpha-synuclein and calcium inside cells. If this is disturbed, it may cause the damage that ultimately leads to brain cell death.
"Understanding exactly how and why brain cells stop working properly and die in Parkinson's is still a mystery. While more research will need to be done, this important new clue could be the key to better treatments in future."