8-cyclopentyltheophylline, an adenosine A(1) receptor antagonist, inhibits the reversal of long-term potentiation in hippocampal CA1 neurons

The effects of an adenosine A(1) receptor antagonist, 8-cyclopentyltheophylline (8-CPT, 1 mu M), on the reduction of long-term potentiation were studied in CA1 neurons of guinea pig hippocampal slices. Reduction of long-term potentiation (depotentiation) was achieved by delivering a train of low-frequency afferent stimuli (low-frequency stimulation, 1000 pulses, 1 Hz) 20 min after the tetanus (100 Hz, 100 pulses). In control experiments, low-frequency stimulation reduced the potentiated component of the slope of the field EPSP reduced to 13.4 +/- 9.7% and 9.0 +/- 10.9% (n = 7) when the low-frequency stimulation was applied during the perfusion with 8-CPT (1 mu M). These results indicate that activation of adenosine A(1) receptors enhances the depotentiation of long-term potentiation. (C) 1997 Elsevier Science B.V.