Nitric oxide facilitates N-methyl-D-aspartate-induced burst firing in dopamine neurons from rat midbrain slices.
Dopamine (DA) neurons in the ventral tegmental area and substantia nigra pars compacta were induced to fire in bursts with application of N-methyl-D-aspartate (NMDA, 20 microM) and apamin (100 nM) while recording intracellularly in the rat brain slice. L-Arginine (300 microM), a substrate for nitric oxide (NO) production, increased both the number of spikes per burst and the magnitude of interburst hyperpolarizations. Nitric oxide synthase inhibitors N-nitro-L-arginine methyl ester (L-NAME, 100 microM), N-nitro-L-arginine, and 7-nitroindazole inhibited NMDA-induced burst firing by reducing the number of spikes per burst. Moreover, L-arginine (100 microM) reversed the inhibition of burst firing produced by L-NAME. These findings suggest that NO facilitates NMDA-induced burst firing in DA neurons.
Cox
B A
BA
Department of Physiology and Pharmacology, Oregon Health Sciences University, Portland 97201, USA.
Johnson
S W
SW
D000818:Animals; D001030:Apamin / Q000494:pharmacology; D001120:Arginine / Q000494:pharmacology; D004298:Dopamine / Q000378:metabolism*; D004357:Drug Synergism; D004594:Electrophysiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D066298:In Vitro Techniques; D007191:Indazoles / Q000494:pharmacology; D008297:Male; D008636:Mesencephalon / Q000166:cytology / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D016202:N-Methylaspartate / Q000494:pharmacology*; D019331:NG-Nitroarginine Methyl Ester / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000378:metabolism / Q000502:physiology*; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley
D004791:Enzyme Inhibitors; D007191:Indazoles; D019335:Nitroarginine; D001030:Apamin; D009569:Nitric Oxide; D016202:N-Methylaspartate; D001120:Arginine; C080122:7-nitroindazole; D019331:NG-Nitroarginine Methyl Ester; D004298:Dopamine