Parkinson’s disease is the second neurodegenerative disease that most affects the world population. Therefore, the scientific community has a great interest in investigating which pathological and biochemical changes are associated with the development of this disease.
Parkinson's disease is a degenerative disease of the central nervous system that mainly affects motor coordination. Worldwide, 7 to 10 million people live with this disease, and it commonly affects people over 60 years old. although it is much more common in people over 60, the number of younger people diagnosed with the disease is reduced. Symptoms appear slowly and gradually over time, and many of them are related with motor control - the ability to control muscles and movements.
In the early stages, the most obvious symptoms are tremors, stiffness, slow movement, postural instability and difficulty walking. In the advanced stages of the disease, the presence of dementia is common.
In Parkinson's disease, there is degeneration and cell death of dopamine-producing neurons. nerve cells of the substantia nigra (an area of the basal ganglia (called the substantia nigra) degenerate, decreasing dopamine production and the number of connections between nerve cells in the basal ganglia.
Dopamine is a neurotransmitter that allows communication between brain cells that are involved in controlling movement. For this reason, a reduction in dopamine levels triggers the onset of symptoms of Parkinson's disease. According to the National Parkinson Foundation, 60-80% of the production of dopamine cells are lost, even before the motor symptoms of Parkinson's disease appear.
Changes in neuron mitochondria are associated with the progression of Parkinson's disease
Currently, no objective analysis method allows to validate the diagnosis of Parkinson's disease, to follow the disease progression, or even to evaluate the effectiveness of possible treatments. However, several scientific studies have already identified 2 biochemical modifications associated with this disease, which have a high diagnostic potential:
The appearance of abnormal aggregations of a key protein (alpha-synuclein) – known as Lewy bodies;
The loss of neurons that contain either the neurotransmitters dopamine or norepinephrine.
Scientists has also observed that the dysfunction of mitochondria is a key piece in the progression of the Parkinson’s disease. Rui Simões, a PhD student of the University of Coimbra, and his research group recently published a scientific paper, aiming to review the role of changes in mitochondrial dynamics in this disease.
Dysfunctional mitochondria can raise the calcium concentration of the interior of the neuron. In turn, calcium can bind to alpha-synuclein, promoting the aggregation of this protein, and thus the disease progression. It was just one of the scientific evidences found between Dysfunctional mitochondria of neurons and the Parkinson's disease. If you are interested in knowing more about the other biochemical changes recorded, check the full article here.
According to the authors, “further work is clearly needed to articulate the full significance of changed mitochondrial dynamics in Parkinson’s disease etiology.”
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