Parkinson’s disease is caused by death of dopamine-producing neurons in the substantia nigra pars compacta (SNPC) region of the brain, an important control center for motor function.[1] The neurons in the SNPC communicate with other regions of the brain to control movement by releasing the neurotransmitter dopamine. When dopamine levels are reduced, the biochemical imbalance creates the characteristic PD motor symptoms such as tremors, bradykinesia, and impaired balance and coordination.[2]
Although neuronal death in the SNPC is responsible for the characteristic symptoms associated with motor function in PD, other areas of the brain are also affected[3] that may contribute to non-motor symptoms.[4]