Electrical activity of no-producing neuron depends on NO level.
NO-producing neuron exhibited an excitatory response to the decrease in NO concentration, which was induced by NO synthase inhibitor N-nitro-L-arginine or specific NO acceptor 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. Addition of NO donors to the medium inhibits neuronal activity. The excitatory effects of N-nitro-L-arginine and 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide were preserved, while the inhibitory action of NO donors significantly decreased after isolation of the neuron. These findings indicate that NO regulates activity of these neurons by the negative feedback mechanism. This regulation includes the following complementary mechanisms: (1) endogenous mechanism of cell self-activation in response to the decrease in NO concentration; and (2) exogenous mechanism of cell-mediated inhibition in response to NO excess.
Dyakonova
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N. K. Kol'tsov Institute of Developmental Biology, Russian Academy of Sciences, Moscow, Russia. dyakonova@nm.ru
Dyakonova
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D000818:Animals; D003497:Cyclic N-Oxides / Q000494:pharmacology; D004594:Electrophysiology; D007093:Imidazoles / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism* / Q000502:physiology*; D009569:Nitric Oxide / Q000378:metabolism*; D020030:Nitric Oxide Donors / Q000494:pharmacology; D019335:Nitroarginine / Q000494:pharmacology; D009599:Nitroprusside / Q000494:pharmacology; D012908:Snails
D003497:Cyclic N-Oxides; D007093:Imidazoles; D020030:Nitric Oxide Donors; D009599:Nitroprusside; C079391:2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide; D019335:Nitroarginine; D009569:Nitric Oxide