Causes of Parkinson's DiseaseNormal movement depends on the appropriate production of a chemical messenger or ‘neurotransmitter’ called dopamine by cells in an area of the brain called the substantia nigra (Figure 1). In people with Parkinson’s disease, the cells in this part of the brain begin to lose their ability to produce this chemical messenger. When a major proportion of the dopamine-producing cells have stopped working, the symptoms of Parkinson’s disease start to appear.
The reason why these dopamine-producing brain cells stop working is still unknown. Scientists think that certain people may have an inherited susceptibility to develop Parkinson’s disease. Other causes, such as environmental effects, have also been tentatively suggested as causes of the condition; however, none of these have been fully confirmed yet4.
Figure 1. In Parkinson’s disease, dopamine-producing cells in the brain degenerate