Evidence for pre- and postsynaptic localization of adenosine A1 receptors in the CA1 region of rat hippocampus: a quantitative autoradiographic study.

The cellular localization of adenosine A1 receptors in the CA1 region of the rat hippocampus was investigated using radioligand binding and lesioning methods in a quantitative autoradiographic study. Kainic acid injection reduced [3H]cyclohexyladenosine binding in the CA3 region by 40% and in the CA1 region by 30%. Transient cerebral ischemia reduced [3H]cyclohexyladenosine binding in the CA1 region by 50%, while no change was measured in the CA3 region. These findings suggest that adenosine A1 receptors are located presynaptically on axon terminals of CA3 pyramidal cells and postsynaptically on the dendrites of CA1 pyramidal cells in the CA1 region of rat hippocampus.