A team, led by researchers from the Champalimaud Foundation (CF), has shown, for the first time it is possible to diagnose Parkinson’s disease (EP) years before it becomes intractable. As? Thank you scan the brain of people with images by functional magnetic resonance (FMRI).
The result of the Poral of Cerevcians.
It has been known for a long time that asymptomatic people who slowly develop Parkinson complain about smell loss. This situation can occur five to ten years before they are seriously illness and experience the complete symptoms of the disease: slow movements, resting tremor, stiffness and postural instability.
The importance of this type of sensory deterioration in Parkinson has not been subject to much research. In addition, although many people report loss of smell, only some will develop Parkinson, which means that the deterioration of smell alone is not a specific biomarker of the disease. However, the people who Parkinson and related disorders develop They can also suffer visual deficits and even hallucinations, and this is where there could be space for more reliable biomarkers.
Now, the Noam Shemesh and Tiago Outeiro, neuroscientist and Parkinson specialist team at the Göttingen University Medical Center have joined efforts and have shown that simultaneously evaluating these two (and perhaps others) sensory deficiencies in the brain could provide a solid biomarker for early Parkinson. And the earlier the diagnosis is, the greater the possibilities of developing effective treatments for patients with Parkinson’s.
Using an experimental magnetic resonance scanner of Ultraalt Field installed in the Shemesh Laboratory, the researchers submitted a Murino Parkinson’s model to a technique called functional magnetic resonance (FMRI). To give an idea of the power of the experimental machine, This generates a 9.4 teslas magnetic field (while medical machines usually reach only 3 teslas). This substantially improves the images and allows a clear vision of brain structures in the small brain of the mouse.
The transgenic mice used here were used in the Outeiro laboratory and presented high levels of a human protein called ALFA-SINCLEÍNA. It is believed that this protein plays a fundamental role in the disease, since it tends to accumulate and form inclusions, also in the black substance, the brain region that produces dopamine and whose progressive degeneration is responsible for motor deficiencies in Parkinson’s. “The aggregates subsequently extend to other regions of the brain and affect the motor areas,” explains Ruxanda Lungu, main co -author of the study.
“This mouse model is very useful,” says Outeiro, “because it produces the human type of alpha-sinuclein.” In addition, mice behavior denotes a smell alteration, and it is also believed that these animals suffer from visual disabilities.
Functional magnetic resonance is used to observe which areas of the animal (or human) brain are activated under certain conditions; In this case, when exposed to smells or visual stimuli. In the complete brain images obtained, The areas are illuminated in response to stimulation due to changes in blood flow and oxygenation, driven by neuronal activity.
Brain activity
The researchers began by comparing, through functional magnetic resonances (FMRI), the brain activity of living mice produced by alpha-sinuclein ovillus with that of their brothers who did not produce them. The mice were about nine months old, equivalent to an intermediate stage of the development of EP.
And, in fact, the main analyzes, carried out by Francisca Fernandes, coping author of the study, showed that the control mice had a normal activity in the corresponding brain areas, while in the Parkinsonian mice there was much less activity.
However, the problem with the FMRI is that «it does not detect the neuronal activity per se,” says Shemesh. »Since it is based on the interactions between the current neuronal activity and vascular properties, it detects a complex combination of both effects«. In the present study, it was essential to unravel these two components to visualize the purely neuronal effects of the disease. “It is extremely difficult to achieve it with the FMRI,” says Shemesh.
Therefore, they also had to use others approaches.
Co -author Sara Monteiro evaluated vascular properties with a method called «cerebral blood flow mapping«And he showed that the vascular effects were, in fact, weaker in the mice with Parkinson’s than in the controls.
At the same time, Lungu measured neuronal contributions by means of a protein called C-Fos, which is released when a neuron is activated. By quantifying the amount of this protein present in the brain of mice with EP (post mortem), he discovered that the reduction of neuronal activity was even more pronounced than that of vascular flow. “We conclude that, although there are both neuronal and vascular effects, the changes observed in functional magnetic resonances were mainly due to neuronal effects,” says Shemesh. «Mice neurons simply activated less».
“As far as we know, this is the first observation of a visual and olfactory sensory aberration combined in the brain activity of rodent models with EP in general and the alpha-sinuclein model in particular,” the authors write in their article.
“The great advantage of this method is that it is really non -invasive and easy to realize,” says Outeiro. “This could enrich the diagnosis and classification of EP, something that is urgently needed,” he adds.
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