For a long time, scientists thought that both movement and thinking problems in Parkinson’s disease were caused by the build-up of a protein called alpha-synuclein in the brain.
But a new study has shown that the cause of thinking problems (like forgetfulness and poor concentration) might be something else entirely.
Researchers from Yale School of Medicine have found that changes (mutations) in a gene called GBA could be the reason people with Parkinson’s disease develop memory and thinking problems. This gene problem interferes with how brain cells talk to each other.
Dr. Sreeganga Chandra, the lead researcher, explained that dementia is one of the most feared symptoms of Parkinson’s disease. Her team wanted to understand what causes the thinking problems and find ways to treat them.
The researchers used three types of mice: one group had too much alpha-synuclein protein, another had GBA gene mutations, and the third had both problems.
They found mice with too much alpha-synuclein had movement problems, but no memory issues. Mice with GBA gene mutations had thinking problems early on, but no movement issues. Mice with both problems had both movement and thinking issues.
This shows that movement problems are caused by the alpha-synuclein protein, while memory and thinking problems are caused by GBA gene mutations.
Further testing showed that brain cells in mice with GBA mutations weren’t talking to each other properly. They found damage in the ‘synapses’—the places where brain cells connect and share messages.
The GBA mutations seem to interfere with how brain cells release and receive chemical messages. This could explain the memory and concentration problems in Parkinson’s patients with this gene mutation.
Dr. Chandra’s team is continuing to study this process in both mice and human brain cells. They hope this will lead to better treatments for the thinking problems in Parkinson’s disease—especially for those caused by GBA mutations.
These new findings show that not all Parkinson’s symptoms are caused by alpha-synuclein. There may be other important causes, like GBA mutations, that researchers need to explore.
If you care about dementia, please read studies about Early heart rhythm problem linked to higher dementia risk and findings of Green leafy vegetables may help reduce Alzheimer’s risk.
For more about dementia, please read studies about Research shows an important cause of frontotemporal dementia and findings of New way to detect Lewy body disease early, a leading cause of dementia.
The study is published in Nature Communications.
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