A functional role for adenosine A3 receptors:: modulation of synaptic plasticity in the rat hippocampus

Adenosine modulates hippocampal synaptic plasticity, namely long-term potentiation (LTP) and long-term depression (LTD), through activation of A(1) and A(2A) receptors. We now report a novel role for the recently described adenosine A(3) receptor in the regulation of synaptic plasticity in the CA1 area of hippocampal slices. Activation of adenosine A(3) receptors by (1-[2-chloro-6-[[(3-iodophenyl)methyl]amino]-9H-purin-p-yl]-1-deoxy-N-methyl-beta -D-ribofuranuronamide (CI-IBMECA) (100 nM) increased the magnitude of theta -burst induced LTP (from 1.2 +/- 0.6% in the control solution to 25.5 +/- 0.8% in the presence of CI-IBMECA) and attenuated LTD (from 30.0 +/- 5.5% decrease in the control solution to 13.6 +/- 6.6% decrease in the presence of CI-IBMECA). The selective adenosine A(3) receptor antagonist, MRS 1191 (5-10 muM), prevented the effects of CI-IBMECA, These findings indicate a functional role for adenosine A(3) receptors in the modulation of synaptic plasticity. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.