8-cyclopentyltheophylline, an adenosine A1 receptor antagonist, inhibits the reversal of long-term potentiation in hippocampal CA1 neurons.
The effects of an adenosine A1 receptor antagonist, 8-cyclopentyltheophylline (8-CPT, 1 microM), 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 and the amplitude of the population spike by 68.5 +/- 14.4% and 80.1 +/- 8.8%, respectively (n = 6); these values were significantly 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 microM). These results indicate that activation of adenosine A1 receptors enhances the depotentiation of long-term potentiation.
Fujii
S
S
Department of Physiology, Yamagata University School of Medicine, Japan. sfujii@med.id.yamagata-u.ac.jp
Sekino
Y
Y
Kuroda
Y
Y
Sasaki
H
H
Ito
K
K
Kato
H
H
D000818:Animals; D004558:Electric Stimulation; D006168:Guinea Pigs; D006624:Hippocampus / Q000187:drug effects*; D066298:In Vitro Techniques; D008297:Male; D009474:Neurons / Q000187:drug effects; D058915:Purinergic P1 Receptor Antagonists; D009435:Synaptic Transmission / Q000187:drug effects; D013806:Theophylline / Q000031:analogs & derivatives* / Q000494:pharmacology
D058915:Purinergic P1 Receptor Antagonists; C053907:8-cyclopentyl-1,3-dimethylxanthine; D013806:Theophylline