The pathophysiology of Parkinson’s primarily involves the degeneration of neurons in a region of the midbrain called the substantia nigra. These neurons produce dopamine, a neurotransmitter crucial for regulating mood, movement and coordination. As these neurons die, they can no longer produce enough dopamine to send messages and cause symptoms like changes in mood, tremors, rigidity, and slowness of movement. Additionally, the presence of Lewy bodies and abnormal aggregates of the protein alpha-synuclein is a pathological feature of Parkinson’s.