LTP-induced depression of response to hypoxia in hippocampus: effects of adenosine receptor activation.
Previous work has shown that long-term potentiation (LTP) can reduce the effects of hypoxia in depressing population spikes in rat hippocampal slices. We have now investigated the role of adenosine in this phenomenon. There is no mutual inhibition between the depressant effects of hypoxia and adenosine, but LTP reduces responses to both hypoxia and adenosine, as does application of an A1 receptor antagonist. The effect of LTP is not due to a change in the balance of activation of A1 and A2A adenosine receptors since a selective A2A receptor antagonist did not prevent the interaction. We suggest that LTP may reduce the response to hypoxia by attenuating neuronal sensitivity to adenosine A1 receptors.
Youssef
Farid F
FF
Department of Pre-Clinical Science, University of the West Indies, St Augustine Campus, Trinidad and Tobago. fmyoussef@tsst.net.tt
Addae
Jonas I
JI
Stone
Trevor W
TW
D000241:Adenosine / Q000494:pharmacology; D000818:Animals; D004558:Electric Stimulation; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects / Q000502:physiology*; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D058906:Purinergic P1 Receptor Agonists; D051381:Rats; D017207:Rats, Sprague-Dawley; D018047:Receptors, Purinergic P1 / Q000378:metabolism*; D014227:Triazines / Q000494:pharmacology; D014230:Triazoles / Q000494:pharmacology
D058906:Purinergic P1 Receptor Agonists; D018047:Receptors, Purinergic P1; D014227:Triazines; D014230:Triazoles; C097270:ZM 241385; D000241:Adenosine