Selective inhibition of homosynaptic depression in a tetanized pathway by an adenosine A1 blocker in the CA1 region of rat hippocampal slice.
The involvement of adenosine A1 receptors in post-tetanic depression (PTD) of CA1, induced by 5 Hz, 20 s stimulation to the Schaffer collateral/commissural fibers was studied in the rat hippocampal slice. The tetanic stimulation induced post-tetanic depression (PTD) lasting for 5-10 min in the excitatory postsynaptic potentials (EPSP) and the population spike (PS) of the tetanized pathway (homosynaptic PTD), and of a non-tetanized pathway (heterosynaptic PTD). 8-Cyclopentyltheophylline (an adenosine A1 antagonist) blocked the induction of homosynaptic PTD, but not of heterosynaptic PTD. These results indicate that adenosine released during tetanic stimulation acts on the A1 receptor to induce the homosynaptic PTD.
Sekino
Y
Y
Department of Physiology, Tokyo Women's Medical College, Japan.
Koyama
I
I
D000818:Animals; D004305:Dose-Response Relationship, Drug; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D008297:Male; D058914:Purinergic Antagonists; D011712:Pyramidal Tracts / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D013806:Theophylline / Q000031:analogs & derivatives* / Q000494:pharmacology; D013997:Time Factors
D058914:Purinergic Antagonists; C053907:8-cyclopentyl-1,3-dimethylxanthine; D013806:Theophylline