Adenosine and synaptic plasticity

Adenosine modulates long-term synaptic plasticity. Application of adenosine Al receptor agonists attenuates long-term potentiation (LTP) in the hippocampus. Endogenous adenosine exerts a tonic inhibitory effect on LTP, since A(1) receptor antagonists consistently facilitate LTP. Adenosine also modulates the reciprocal phenomenon of synaptic plasticity, long-term depression (LTD), and depotentiation in a way that depends on the specific induction protocol. Application of adenosine AZA receptor agonists can facilitate LTP, but the role of endogenous adenosine mediated through AZA receptors in the modulation of synaptic plasticity is still the subject of controversy. The effects of adenosine on synaptic plasticity mediated through A(3) receptors have been described. In accordance with the notion that synaptic plasticity is the basis for learning and memory in different brain areas, adenosine correspondingly modulates behavior in various learning and memory paradigms. The effects of adenosine on synaptic plasticity should be relevant for the enhancement of intellectual performance related to caffeine intake. Adenosinergic compounds might prove helpful in the treatment of memory disorders. Drug Dev. Res. 52:283-290, 2001. (C) 2001 Wiley-Liss, Inc.