T1. Introduction
Caffeine probably causes most of its biological effects by blocking all
adenosine receptors located at the neurons and brain glial cells and
removing the brain's adenosinergic tonus (Ribeiro and Sebastião,
2010). Animal models suggest that 1) adenosine plays a role opposite
to dopamine in the striatum; 2) adenosine agonists produce effects
similar to dopamine antagonists; and 3) adenosine antagonists, such as caffeine, produce effects similar to increased dopaminergic neurotransmission
(Ferré, 1997).