Inhibitory action of N omega-nitro-L-arginine methyl ester on in vivo long-term potentiation in the rat dentate gyrus.
Recent in vitro observations have led to the suggestion that nitric oxide (NO) plays a modulatory role in the expression of long-term potentiation (LTP). We investigated whether an NO synthesis inhibitor, N omega-nitro-L-arginine methyl ester (L-NAME), affects the generation of LTP in anesthetized rats in vivo. Administration of L-NAME (0.1 and 1 nmol, i.c.v.) suppressed the magnitude of LTP dose dependently in the dentate gyrus of anesthetized rats. Co-injection of L-arginine, which interferes with the inhibitory action of L-NAME on NO synthesis, reversed these effects, whereas there was no reversal in rats that received co-administration with D-arginine. These results provide further support for the hypothesis that NO plays a modulatory role in the expression of synaptic potentiation.
Iga
Y
Y
First Department of Pharmacology, Hokkaido University School of Medicine, Sapporo, Japan.
Yoshioka
M
M
Togashi
H
H
Saito
H
H
D000818:Animals; D001120:Arginine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology; D004558:Electric Stimulation; D005071:Evoked Potentials / Q000187:drug effects; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology; D007276:Injections, Intraventricular; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D009569:Nitric Oxide / Q000037:antagonists & inhibitors; D051381:Rats; D017208:Rats, Wistar; D013237:Stereoisomerism
D009569:Nitric Oxide; D001120:Arginine; D019331:NG-Nitroarginine Methyl Ester