What is Parkinson's disease primarily caused by?

Parkinson's disease is primarily caused by the degeneration of dopamine-producing cells, specifically located in a part of the brain called the substantia nigra. These cells produce dopamine, a neurotransmitter that plays a crucial role in controlling movement and coordination. As these cells deteriorate, there is a significant reduction in dopamine levels, leading to the characteristic motor symptoms of Parkinson's disease, such as tremors, stiffness, and bradykinesia (slowness of movement).

Understanding the underlying mechanism of the disease is essential for recognizing its impact on motor function and how it can be treated. Treatments often focus on increasing dopamine levels or mimicking its action to alleviate symptoms. Other answers involve processes that are relevant to different neurological conditions but are not primary causes of Parkinson's disease, thereby distinguishing Parkinson's from those conditions.