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-cyclopentylthe ophylline (8-CPT, 1 mu M), on the reduction of long-term potentiation were studied in CA1 neurons of guinea pig hippocampal slices. Reductio n of long-term potentiation (depotentiation) was achieved by deliverin g 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 potentiate d component of the slope of the field EPSP reduced to 13.4 +/- 9.7% an d 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.