The suppression of long-term potentiation in rat hippocampus by inhibitors of nitric oxide synthase is temperature and age dependent.
At room temperature (23 degrees C-25 degrees C), the induction of long-term potentiation (LTP) in area CA1 of slices from young male Sprague-Dawley rats was depressed by preincubation with the nitric oxide synthase inhibitors NG-nitro-L-arginine (L-NA, 100 microM) and NG-nitro-L-arginine methyl ester (L-NAME, 100 microM). The D isomers were ineffective under the same conditions. Hemoglobin (20 microM) reduced but did not completely block LTP. Neither L-NA (at concentrations up to 1 mM) nor hemoglobin (20 microM) had any significant effect on LTP in slices from adult rats at room temperature, or in young rats at 29 degrees C-30 degrees C. These results suggest that nitric oxide is unlikely to play a role in the induction of LTP under physiological conditions.
Williams
J H
JH
Division of Neurophysiology and Neuropharmacology, National Institute for Medical Research, Mill Hill, England.
Li
Y G
YG
Nayak
A
A
Errington
M L
ML
Murphy
K P
KP
Bliss
T V
TV
D000375:Aging / Q000502:physiology*; D000594:Amino Acid Oxidoreductases / Q000037:antagonists & inhibitors*; D000818:Animals; D001120:Arginine / Q000031:analogs & derivatives / Q000494:pharmacology; D006454:Hemoglobins / Q000494:pharmacology; D006624:Hippocampus / Q000187:drug effects* / Q000502:physiology*; D066298:In Vitro Techniques; D017774:Long-Term Potentiation / Q000187:drug effects*; D008297:Male; D019331:NG-Nitroarginine Methyl Ester; D019001:Nitric Oxide Synthase; D019335:Nitroarginine; D051381:Rats; D017207:Rats, Sprague-Dawley; D013696:Temperature
D006454:Hemoglobins; D019335:Nitroarginine; D001120:Arginine; D019001:Nitric Oxide Synthase; D000594:Amino Acid Oxidoreductases; D019331:NG-Nitroarginine Methyl Ester