How do adenosine A receptors regulate motor function?

Adenosine A receptor antagonism is a new therapeutic strategy in the symptomatic treatment of Parkinson's disease (PD). This review addresses how adenosine A receptors are involved with the control of motor function via the basal ganglia-thalamocortical circuit, and considers the anatomical localization and physiological function of the receptor, along with its ultrastructural localization in critical areas/neurons of the circuit. Based on this understanding of the functional significance of the adenosine A receptor in the basal ganglia, the mode of action of A receptor antagonists is explored in terms of the dynamic functioning of the basal ganglia and the activity of the internal circuits of the striatum in PD. Finally, the pathophysiological differences between the normal and PD states are examined to emphasize the importance of the adenosine A receptor.