Parkinson's disease is a degenerative, progressive disorder that affects nerve cells in deep parts of the brain called the basal ganglia and the substantia nigra. Nerve cells in the substantia nigra produce the neurotransmitter dopamine and are responsible for relaying messages that plan and control body movement.
Related Theory
Dopamine plays important roles in executive function, motor control, motivation, arousal, reinforcement, and reward through signaling cascades that are exerted via binding to dopaminergic receptors.
Caution
Dopamine system is linked to motivation. Serotonin is involved in emotions, which can affect your overall mood.