[The Relationship Between Pathophysiology and Neurotransmitters in Parkinson's Disease]

Parkinson's disease (PD) is a progressive neurodegenerative disorder. The major motor symptoms of PD are mainly caused by dopamine (DA) deficiency due to the loss of dopaminergic neurons in the substantia nigra. Most patients also show non-motor symptoms, such as cognitive impairment, mood disturbance, pain, and sleep disturbance. These symptoms cannot be explained by DA deficiency alone and are likely involved with other neurotransmitter systems, including glutamate, serotonin, noradrenaline, or gamma aminobutyric acid. Other neurotransmitters may have therapeutic effects on some symptoms of PD. In this review, we discuss the pathophysiology of Parkinsonian symptoms, with a focus on neurotransmitters. (Received 2 February, 2021; Accepted 16 February, 2021; Published 1 July, 2021).