Nitric oxide but not carbon monoxide is involved in spatial learning of mice.
The aim of the present study was to elucidate the role of carbon monoxide (CO) in learning and to compare it with that of nitric oxide (NO). Effects of an inhibitor of heme oxygenase which produces CO, Zn-protoporphyrin IX, on passive avoidance learning and spatial learning in mice were examined using step through, step down and water maze tests. Zn-protoporphyrin IX (10, 20 nmol, i.c.v.) affected neither type of learning. In contrast, N-omega-nitro-L-arginine (40 nmol, i.c.v.), an inhibitor of NO synthase, impaired spatial learning, but not passive avoidance learning. These results suggest that NO but not CO is involved in spatial learning.
Toyoda
M
M
Department of Chemical Pharmacology, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Saito
H
H
Matsuki
N
N
D000818:Animals; D001362:Avoidance Learning / Q000187:drug effects; D001835:Body Weight; D002248:Carbon Monoxide / Q000494:pharmacology*; D017774:Long-Term Potentiation / Q000187:drug effects; D008297:Male; D018782:Maze Learning / Q000187:drug effects; D051379:Mice; D009043:Motor Activity / Q000187:drug effects; D009569:Nitric Oxide / Q000502:physiology*; D019335:Nitroarginine / Q000494:pharmacology; D011524:Protoporphyrins / Q000494:pharmacology
D011524:Protoporphyrins; C017803:zinc protoporphyrin; D019335:Nitroarginine; D009569:Nitric Oxide; D002248:Carbon Monoxide