Effect of hypoxia on excitatory transmission in the rat substantia gelatinosa neurons.
We have investigated the effect of hypoxia on the excitatory synaptic transmission in the substantia gelatinosa neurons using perforated-patch-clamp configuration. Brief periods of hypoxia induced a depression in the evoked excitatory postsynaptic current (eEPSC) amplitude. The hypoxia-induced depression of eEPSC was not observed in the presence of theophylline, a nonselective adenosine receptor antagonist, and DPCPX, a selective adenosine receptor A1 antagonist. Application of adenosine (100 microM) also depressed eEPSC in a similar way as with hypoxia. This adenosine-induced depression of eEPSC was inhibited by DPCPX. Hypoxia and exogenous adenosine decreased the frequency of the spontaneous excitatory postsynaptic current (sEPSC) but not the amplitude of sEPSC and increased the paired-pulse ratio. From these results, it is suggested that acute hypoxia depresses the excitatory synaptic transmission by activating the presynaptic adenosine A1 receptor.
Department of Physiology and Biophysics, Seoul National University College of Medicine, 28 Yongon-dong, Chongno-gu, Seoul, Republic of Korea.
Yun
Y
Kyung Park
Sung
S
Jun Jung
Jiyeon
J
Kwak
Jun
J
Kim
D000241:Adenosine / Q000378:metabolism / Q000494:pharmacology; D000700:Analgesics / Q000494:pharmacology; D000818:Animals; D004594:Electrophysiology; D000860:Hypoxia / Q000378:metabolism*; D009474:Neurons / Q000378:metabolism*; D018408:Patch-Clamp Techniques; D010726:Phosphodiesterase Inhibitors / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D018047:Receptors, Purinergic P1 / Q000378:metabolism; D013376:Substantia Gelatinosa / Q000378:metabolism*; D013569:Synapses / Q000378:metabolism; D013806:Theophylline / Q000494:pharmacology*; D013997:Time Factors
D000700:Analgesics; D010726:Phosphodiesterase Inhibitors; D018047:Receptors, Purinergic P1; D013806:Theophylline; D000241:Adenosine