The Role of CBGTC Synaptic Neurotransmission in the Pathophysiology of Tics.

The pathophysiology of tic disorders involves an alteration in the transmission of messages through the cortico-basal ganglia-thalamo-cortical circuit. A major requirement for the passage of a message through this circuit is an intact chemically mediated synaptic neurotransmitter system (ie, neurotransmitters and second messengers). This article reviews the scientific evidence supporting the involvement of a variety of neurotransmitters (ie, dopamine, glutamate, gamma-aminobutyric acid, serotonin, acetylcholine, and the opioid system). Although there are favored neurotransmitter abnormalities, their complex interactions suggest the likelihood that several are involved in the production of tics.