Nitric oxide-related species inhibit evoked neurotransmission but enhance spontaneous miniature synaptic currents in central neuronal cultures.
Nitric oxide (NO.) does not react significantly with thiol groups under physiological conditions, whereas a variety of endogenous NO donor molecules facilitate rapid transfer to thiol of nitrosonium ion (NO+, with one less electron than NO.). Here, nitrosonium donors are shown to decrease the efficacy of evoked neurotransmission while increasing the frequency of spontaneous miniature excitatory postsynaptic currents (mEPSCs). In contrast, pure NO donors have little effect (displaying at most only a slight increase) on the amplitude of evoked EPSCs and frequency of spontaneous mEPSCs in our preparations. These findings may help explain heretofore paradoxical observations that the NO moiety can either increase, decrease, or have no net effect on synaptic activity in various preparations.
Pan
Z H
ZH
Department of Neurology, Children's Hospital, Boston, MA 02115, USA.
Segal
M M
MM
Lipton
S A
SA
D000818:Animals; D001048:Aplysia; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000502:physiology*; D006152:Cyclic GMP / Q000031:analogs & derivatives / Q000378:metabolism / Q000494:pharmacology; D003545:Cysteine / Q000031:analogs & derivatives / Q000494:pharmacology; D005033:Ethylmaleimide / Q000494:pharmacology; D005333:Fetus; D006624:Hippocampus / Q000502:physiology; D006834:Hydrazines / Q000494:pharmacology; D007700:Kinetics; D009457:Neuroglia / Q000187:drug effects / Q000502:physiology*; D009474:Neurons / Q000187:drug effects / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D009589:Nitrogen Oxides; D005996:Nitroglycerin / Q000494:pharmacology; D018408:Patch-Clamp Techniques; D051381:Rats; D017207:Rats, Sprague-Dawley; D026403:S-Nitrosothiols; D013569:Synapses / Q000187:drug effects / Q000502:physiology*; D009435:Synaptic Transmission / Q000187:drug effects*
D006834:Hydrazines; D009589:Nitrogen Oxides; D026403:S-Nitrosothiols; C016276:8-bromocyclic GMP; D009569:Nitric Oxide; C084012:1,1-diethyl-2-hydroxy-2-nitrosohydrazine; C021315:S-nitrosocysteine; D005996:Nitroglycerin; D006152:Cyclic GMP; D003545:Cysteine; D005033:Ethylmaleimide