Scientists estimate a human brain has around 86 billion neurons, the cells that make up our brain and nervous system. Dopaminergic neurons make up only a few percent of our neurons, but play a big role in our ability to control our movements. Unlike other cells, dopaminergic neurons cannot regenerate: if they are lost, they are lost for good.
Loss of neurons, loss of control
The loss of these neurons is why people who have Parkinson’s disease experience the most well-known symptoms of this disease: shaking and loss of control of movements.
There is no cure for Parkinson’s and while science has come a long way in characterising the disease, many questions remain, such as: why do the dopaminergic neurons of these people degenerate?
Looking for clues inside the neurons
Neuroscientist Prof. Anne Grünewald and her team at the University of Luxembourg’s Centre for Systems Biomedicine (LCSB) study mitochondria, the powerhouse of these cells, to see if clues could be found here.
“What is special about mitochondrial DNA is there is not just one or two copies of DNA per cell, but hundreds. It makes sense to look at individual cells, because they might be different in their characteristics from one to the other.
Prof Anne Grünewald, University of Luxembourg
Anne has come to Luxembourg to do her research thanks to an FNR ATTRACT Fellowship, as part of which the FNR gives promising young scientists the chance to come (or return) to Luxembourg to set up their own research group. She has since become a Full Professor at the LCSB!
Discover more about the research of Anne Grünewald’s lab in the video below, or read our interview with Anne on fnr.lu.
NCER-PD: Luxembourg’s centre for research on Parkinson’s Disease
Parkinson’s disease is mainly characterised by trouble with movement: symptoms such as tremor, rigidity, and slowness of movement. Cognitive impairment and depression can also manifest. There is still no cure and no way to stop the disease from getting worse, the only option for patients is managing the symptoms with treatment.
Up to 1300 people in Luxembourg, and more than 6-10 million people in the world are living with Parkinson’s disease. One well-known person who is living with this disease is actor Michael J Fox.
Luxembourg is very active in the field of Parkinson’s disease research, with dozens of running research projects. Many of them contribute to a large 8-year research programme (NCER-PD), which the FNR supports with around 14 MEUR.
The large-scale NCER-PD research effort in Luxembourg aims to understand the mechanism of Parkinson’s disease to enable earlier diagnosis and to develop better treatments for patients.
After only four years, NCER-PD is already among the 7% of the largest cohorts of Parkinson’s patients in the world. A key element that makes the Luxembourg cohort unique is that all patients are followed annually over the years, giving researchers unprecedented information on the progression of the disease.
Over 1600 study participants helping make it possible
NCER-PD provides an important contribution to the research field of this disease. The interdisciplinary research team compares people with Parkinson’s disease with control subjects – people without the disease.
Over 1600 study participants from Luxembourg and the greater region have already taken part in clinical examinations. These clinical examinations cover many aspects, such as motor skills, memory and the sense of smell, biological samples such as blood and saliva and coming for regular follow-up visits.
Focusing on these clinical and biomedical analyses, the research team aims to a better understanding of the diversity of Parkinson’s disease and its underlying mechanisms.
“Only by combining numerous disciplines – from medical practice, to laboratory research, to computer science – could we understand the cause and at the same time identify active substances for a potential treatment.
Prof Rejko Krüger, one of the key researchers leading this large research effort.
“This kind of scientific progress ‘Made in Luxembourg’ is possible because all the necessary disciplines are unified in Luxembourg.”
Focus on sleep disorders: People with REM sleep disorders could be at higher risk
Parkinson’s disease, a neurodegenerative disorder, is mostly diagnosed when people experience first motor symptoms, such as tremor, rigidity, and slowness of movement. These motor symptoms only appear after an important part of the neurons is already lost.
It is still only possible to diagnose Parkinson’s disease when symptoms have already started because of the death of the dopaminergic neurons. Researchers are working to identify early indicators of the disease in the quest for making it possible to diagnose sooner.
Research has already identified early signs for Parkinson’s disease such as the loss of smell, constipation, depression, and sleep disorder, but much remains to be discovered. Therefore, the Luxembourgish research group NCER-PD has started a risk cohort: They invited participants with a specific sleep disorder associated with an increased risk of developing Parkinson’s disease, namely REM sleep behaviour disorder. People with this kind of sleep disorder move excessively during the dream stage as they are acting out their dreams. Often, they punch and kick so harshly that even their bed partner suffers.
With the help of this first risk cohort, the NCER-PD researchers are aiming to get a better understanding of the connection between this sleep disorder and the higher risk of developing Parkinson’s disease. A better understanding of this connection will help to detect the disease in an earlier stage. These kind of research efforts will be beneficial when research develops neuroprotective therapies to slow down or even stop the progression of the disease.
A brain bank in Luxembourg
There is still much research does not know about the human brain and its diseases. Identifying neurological disorders is very complex and often the exact disease can only be identified after death. Therefore, researchers need to compare affected brains with healthy brains. Given that, examining the brain tissue of a living person is very complicated, researchers need to study human tissue after death.
Neuropathologist Prof. Dr. Michel Mittelbronn’s main research mission was to develop a brain repository in Luxembourg collecting post-mortem human brains for scientific research. With this brain bank he aims to develop better diagnostic and treatment strategies for neurodegenerative disorders and brain tumors, such as Parkinson’s disease.
Before, brain samples had to be sent abroad – thanks to the brain bank, these samples can now be analysed in Luxembourg. The brain bank is already able to analyse many thousands of samples each year – making a huge difference to patients.
Prof Michel Mittelbronn’s research is supported by a grant from the FNR’s PEARL programme.
