Adenosine receptor (primarily A2A, also A1, A2B, A3)

The principal central nervous system targets responsible for the stimulant effects of caffeine-containing botanicals are the adenosine receptors, most notably the adenosine A2A receptor (also acting at A1, A2B, and A3, but with lower affinity). Caffeine acts as a nonselective, competitive antagonist of adenosine receptors, blocking the suppressive effects of endogenous adenosine on neuronal activity. This antagonism results in increased neurotransmitter release (including dopamine, norepinephrine, and acetylcholine), greater arousal, reduced fatigue, and heightened cognitive function. Other methylxanthines such as theophylline and theobromine act similarly, though with differing potencies. The canonical molecular classification of the target is G protein-coupled receptor (GPCR), within the P1 purinergic receptor family. Central nervous system stimulation via caffeine is pharmacologically mediated, not a target itself, but the concept maps directly to the antagonism of adenosine receptors[1][2][4][5][6][7].

Other names

Adenosine receptoradenosine A2A receptorA1 receptorA2B receptorA3 receptor

Competitive antagonism of adenosine receptors, blocking adenosine-induced neuronal inhibition and disinhibition of neurotransmitter release, leading to increased arousal, alertness, and CNS stimulation[1][2][4][5][6][7].